1
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Jensen IM, Clark V, Kirby HL, Arroyo-Currás N, Jenkins DM. Tuning N-heterocyclic carbene wingtips to form electrochemically stable adlayers on metals. MATERIALS ADVANCES 2024; 5:7052-7060. [PMID: 39156595 PMCID: PMC11325317 DOI: 10.1039/d4ma00648h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2024] [Accepted: 08/08/2024] [Indexed: 08/20/2024]
Abstract
Self-assembled monolayers (SAMs) are employed in electrochemical biosensors to passivate and functionalize electrode surfaces. These monolayers prevent the occurrence of undesired electrochemical reactions and act as scaffolds for coupling bioaffinity reagents. Thiols are the most common adlayer used for this application; however, the thiol-gold bond is susceptible to competitive displacement by naturally occurring solvated thiols in biological fluids, as well as to desorption under continuous voltage interrogation. To overcome these issues, N-heterocyclic carbene (NHC) monolayers have been proposed as an alternative for electrochemical biosensor applications due to the strong carbon-gold bond. To maximize the effectiveness of NHCs for SAMs, a thorough understanding of both the steric effects of wingtip substituents and NHC precursor type to the passivation of electrode surfaces is required. In this study, five different NHC wingtips as well as two kinds of NHC precursors were evaluated. The best performing NHC adlayers can be cycled continuously for four days (over 30 000 voltammetric cycles) without appreciably desorbing from the electrode surface. Benchmark thiol monolayers, in contrast, rapidly desorb after only twelve hours. Investigations also show NHC adlayer formation on other biosensor-relevant electrodes such as platinum and palladium.
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Affiliation(s)
- Isabel M Jensen
- Department of Chemistry University of Tennessee Knoxville Knoxville TN 37996 USA
| | - Vincent Clark
- Chemistry-Biology Interface Program Johns Hopkins University Baltimore MD 21218 USA
| | - Harper L Kirby
- Department of Chemistry University of Tennessee Knoxville Knoxville TN 37996 USA
| | - Netzahualcóyotl Arroyo-Currás
- Chemistry-Biology Interface Program Johns Hopkins University Baltimore MD 21218 USA
- Department of Pharmacology and Molecular Sciences Johns Hopkins University School of Medicine Baltimore MD 21205 USA
| | - David M Jenkins
- Department of Chemistry University of Tennessee Knoxville Knoxville TN 37996 USA
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2
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Flynn CD, Riordan KT, Young TL, Chang D, Wu Z, Isaacson SE, Yousefi H, Das J, Kelley SO. Self-Assembled Monolayer Transporters Enable Reagentless Analysis of Small Molecule Analytes. ACS Sens 2024; 9:3864-3869. [PMID: 39074375 DOI: 10.1021/acssensors.4c00861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/31/2024]
Abstract
The detection of small molecules beyond glucose remains an ongoing challenge in the field of biomolecular sensing owing to their small size, diverse structures, and lack of alternative non-enzymatic sensing methods. Here, we present a new reagentless electrochemical approach for small molecule detection that involves directed movement of electroactive analytes through a self-assembled monolayer to an electrode surface. Using this method, we demonstrate detection of several physiologically relevant small molecules as well as the capacity for the system to operate in several biological fluids. We anticipate that this mechanism will further improve our capacity for small molecule measurement and provide a new generalizable monolayer-based technique for electrochemical assessment of various electroactive analytes.
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Affiliation(s)
- Connor D Flynn
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S3M2
- Department of Chemistry, Weinberg College of Arts & Sciences, Northwestern University, Evanston, Illinois 60208 United States
| | - Kimberly T Riordan
- Department of Chemistry, Weinberg College of Arts & Sciences, Northwestern University, Evanston, Illinois 60208 United States
| | - Tiana L Young
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada M5S3M2
| | - Dingran Chang
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada M5S3M2
| | - Zhenwei Wu
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, Illinois 60208 United States
| | - Scott E Isaacson
- Department of Chemistry, Weinberg College of Arts & Sciences, Northwestern University, Evanston, Illinois 60208 United States
| | - Hanie Yousefi
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, Illinois 60208 United States
- Chan Zuckerberg Biohub Chicago, Chicago, Illinois 60642 United States
| | - Jagotamoy Das
- Department of Chemistry, Weinberg College of Arts & Sciences, Northwestern University, Evanston, Illinois 60208 United States
| | - Shana O Kelley
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S3M2
- Department of Chemistry, Weinberg College of Arts & Sciences, Northwestern University, Evanston, Illinois 60208 United States
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada M5S3M2
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, Illinois 60208 United States
- International Institute for Nanotechnology, Northwestern University, Evanston, Illinois 60208 United States
- Department of Biochemistry, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611 United States
- Simpson Querrey Institute, Northwestern University, Chicago, Illinois 60611 United States
- Chan Zuckerberg Biohub Chicago, Chicago, Illinois 60642 United States
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3
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Ye C, Lukas H, Wang M, Lee Y, Gao W. Nucleic acid-based wearable and implantable electrochemical sensors. Chem Soc Rev 2024; 53:7960-7982. [PMID: 38985007 PMCID: PMC11308452 DOI: 10.1039/d4cs00001c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2024]
Abstract
The rapid advancements in nucleic acid-based electrochemical sensors for implantable and wearable applications have marked a significant leap forward in the domain of personal healthcare over the last decade. This technology promises to revolutionize personalized healthcare by facilitating the early diagnosis of diseases, monitoring of disease progression, and tailoring of individual treatment plans. This review navigates through the latest developments in this field, focusing on the strategies for nucleic acid sensing that enable real-time and continuous biomarker analysis directly in various biofluids, such as blood, interstitial fluid, sweat, and saliva. The review delves into various nucleic acid sensing strategies, emphasizing the innovative designs of biorecognition elements and signal transduction mechanisms that enable implantable and wearable applications. Special perspective is given to enhance nucleic acid-based sensor selectivity and sensitivity, which are crucial for the accurate detection of low-level biomarkers. The integration of such sensors into implantable and wearable platforms, including microneedle arrays and flexible electronic systems, actualizes their use in on-body devices for health monitoring. We also tackle the technical challenges encountered in the development of these sensors, such as ensuring long-term stability, managing the complexity of biofluid dynamics, and fulfilling the need for real-time, continuous, and reagentless detection. In conclusion, the review highlights the importance of these sensors in the future of medical engineering, offering insights into design considerations and future research directions to overcome existing limitations and fully realize the potential of nucleic acid-based electrochemical sensors for healthcare applications.
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Affiliation(s)
- Cui Ye
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA.
| | - Heather Lukas
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA.
| | - Minqiang Wang
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA.
| | - Yerim Lee
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA.
| | - Wei Gao
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA.
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4
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Guo K, Grünberg R, Ren Y, Chang T, Wustoni S, Strnad O, Koklu A, Díaz‐Galicia E, Agudelo JP, Druet V, Castillo TCH, Moser M, Ohayon D, Hama A, Dada A, McCulloch I, Viola I, Arold ST, Inal S. SpyDirect: A Novel Biofunctionalization Method for High Stability and Longevity of Electronic Biosensors. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2306716. [PMID: 38161228 PMCID: PMC11251562 DOI: 10.1002/advs.202306716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/21/2023] [Indexed: 01/03/2024]
Abstract
Electronic immunosensors are indispensable tools for diagnostics, particularly in scenarios demanding immediate results. Conventionally, these sensors rely on the chemical immobilization of antibodies onto electrodes. However, globular proteins tend to adsorb and unfold on these surfaces. Therefore, self-assembled monolayers (SAMs) of thiolated alkyl molecules are commonly used for indirect gold-antibody coupling. Here, a limitation associated with SAMs is revealed, wherein they curtail the longevity of protein sensors, particularly when integrated into the state-of-the-art transducer of organic bioelectronics-the organic electrochemical transistor. The SpyDirect method is introduced, generating an ultrahigh-density array of oriented nanobody receptors stably linked to the gold electrode without any SAMs. It is accomplished by directly coupling cysteine-terminated and orientation-optimized spyTag peptides, onto which nanobody-spyCatcher fusion proteins are autocatalytically attached, yielding a dense and uniform biorecognition layer. The structure-guided design optimizes the conformation and packing of flexibly tethered nanobodies. This biolayer enhances shelf-life and reduces background noise in various complex media. SpyDirect functionalization is faster and easier than SAM-based methods and does not necessitate organic solvents, rendering the sensors eco-friendly, accessible, and amenable to scalability. SpyDirect represents a broadly applicable biofunctionalization method for enhancing the cost-effectiveness, sustainability, and longevity of electronic biosensors, all without compromising sensitivity.
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Affiliation(s)
- Keying Guo
- Computational Bioscience Research Center (CBRC), Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Raik Grünberg
- Computational Bioscience Research Center (CBRC), Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Yuxiang Ren
- Computational Bioscience Research Center (CBRC), Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Tianrui Chang
- Computational Bioscience Research Center (CBRC), Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Shofarul Wustoni
- Computational Bioscience Research Center (CBRC), Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Ondrej Strnad
- Computer, Electrical and Mathematical Science and EngineeringKAUSTThuwal23955‐6900Saudi Arabia
| | - Anil Koklu
- Computational Bioscience Research Center (CBRC), Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Escarlet Díaz‐Galicia
- Computational Bioscience Research Center (CBRC), Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Jessica Parrado Agudelo
- Computational Bioscience Research Center (CBRC), Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Victor Druet
- Computational Bioscience Research Center (CBRC), Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Tania Cecilia Hidalgo Castillo
- Computational Bioscience Research Center (CBRC), Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | | | - David Ohayon
- Computational Bioscience Research Center (CBRC), Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Adel Hama
- Computational Bioscience Research Center (CBRC), Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Ashraf Dada
- King Faisal Specialist Hospital & Research Centre (KFSH‐RC)Jeddah21499Saudi Arabia
| | - Iain McCulloch
- Department of ChemistryUniversity of OxfordOxfordOX1 3TAUK
| | - Ivan Viola
- Computer, Electrical and Mathematical Science and EngineeringKAUSTThuwal23955‐6900Saudi Arabia
| | - Stefan T. Arold
- Computational Bioscience Research Center (CBRC), Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
- Centre de Biologie Structurale (CBS), INSERM, CNRSUniversité de MontpellierMontpellierF‐34090France
| | - Sahika Inal
- Computational Bioscience Research Center (CBRC), Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
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5
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Olivan LA, Hand K, White RJ. Utilization of Spontaneous Alkyne-Gold Self-Assembly Chemistry as an Alternative Method for Fabricating Electrochemical Aptamer-Based Sensors. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:12117-12123. [PMID: 38826127 DOI: 10.1021/acs.langmuir.4c00972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Electrochemical aptamer-based (E-AB) sensors are a promising class of biosensors which use structure-switching redox-labeled oligonucleotides (aptamers) codeposited with passivating alkanethiol monolayers on electrode surfaces to specifically bind and detect target analytes. Signaling in E-AB sensors is an outcome of aptamer conformational changes upon target binding, with the sequence of the aptamer imparting specificity toward the analyte of interest. The change in conformation translates to a change in electron transfer between the redox label attached to the aptamer and the underlying electrode and is related to analyte concentration, allowing specific electrochemical detection of nonelectroactive analytes. E-AB sensor measurements are reagentless with time resolutions of seconds or less and may be miniaturized into the submicron range. Traditionally these sensors are fabricated using thiol-on-gold chemistry. Here we present an alternate immobilization chemistry, gold-alkyne binding, which results in an increase in sensor lifetimes under ideal conditions by up to ∼100%. We find that gold-alkyne binding is spontaneous and supports efficient E-AB sensor signaling with analytical performance characteristics similar to those of thiol generated monolayers. The surface modification differs from gold-thiol binding only in the time and aptamer concentration required to achieve similar aptamer surface coverages. In addition, alkynated aptamers differ from their thiolated analogues only by their chemical handle for surface attachment, so any existing aptamers can be easily adapted to utilize this attachment strategy.
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Affiliation(s)
- Lars Alexander Olivan
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0171, United States
| | - Kaitlyn Hand
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0171, United States
| | - Ryan J White
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0171, United States
- Department of Electrical and Computer Engineering, University of Cincinnati, Cincinnati, Ohio 45221, United States
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6
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Davis N, Heikenfeld J, Milla C, Javey A. The challenges and promise of sweat sensing. Nat Biotechnol 2024; 42:860-871. [PMID: 38212492 DOI: 10.1038/s41587-023-02059-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 11/07/2023] [Indexed: 01/13/2024]
Abstract
The potential of monitoring biomarkers in sweat for health-related applications has spurred rapid growth in the field of wearable sweat sensors over the past decade. Some of the key challenges have been addressed, including measuring sweat-secretion rate and collecting sufficient sample volumes for real-time, continuous molecular analysis without intense exercise. However, except for assessment of cystic fibrosis and regional nerve function, the ability to accurately measure analytes of interest and their physiological relevance to health metrics remain to be determined. Although sweat is not a crystal ball into every aspect of human health, we expect sweat measurements to continue making inroads into niche applications involving active sweating, such as hydration monitoring for athletes and physical laborers and later for medical and casual health monitoring of relevant drugs and hormones.
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Affiliation(s)
- Noelle Davis
- Electrical Engineering and Computer Sciences, University of California at Berkeley, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jason Heikenfeld
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA.
- Department of Electrical and Computer Engineering, University of Cincinnati, Cincinnati, OH, USA.
| | - Carlos Milla
- The Stanford Cystic Fibrosis Center, Center for Excellence in Pulmonary Biology, Stanford School of Medicine, Palo Alto, CA, USA.
| | - Ali Javey
- Electrical Engineering and Computer Sciences, University of California at Berkeley, Berkeley, CA, USA.
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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7
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Siddiqui AR, N'Diaye J, Santiago-Carboney A, Martin K, Bhargava R, Rodríguez-López J. Spectroelectrochemical determination of thiolate self-assembled monolayer adsorptive stability in aqueous and non-aqueous electrolytes. Analyst 2024; 149:2842-2854. [PMID: 38600773 DOI: 10.1039/d4an00241e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
Self-assembled monolayers (SAM) are ubiquitous in studies of modified electrodes for sensing, electrocatalysis, and environmental and energy applications. However, determining their adsorptive stability is crucial to ensure robust experiments. In this work, the stable potential window (SPW) in which a SAM-covered electrode can function without inducing SAM desorption was determined for aromatic SAMs on gold electrodes in aqueous and non-aqueous solvents. The SPWs were determined by employing cyclic voltammetry, attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), and surface plasmon resonance (SPR). The electrochemical and spectroscopic findings concluded that all the aromatic SAMs used displayed similar trends and SPWs. In aqueous systems, the SPW lies between the reductive desorption and oxidative desorption, with pH being the decisive factor affecting the range of the SPW, with the widest SPW observed at pH 1. In the non-aqueous electrolytes, the desorption of SAMs was observed to be slow and progressive. The polarity of the solvent was the main factor in determining the SPW. The lower the polarity of the solvent, the larger the SPW, with 1-butanol displaying the widest SPW. This work showcases the power of spectroelectrochemical analysis and provides ample future directions for the use of non-polar solvents to increase SAM stability in electrochemical applications.
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Affiliation(s)
- Abdur-Rahman Siddiqui
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois, 61801, USA.
| | - Jeanne N'Diaye
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois, 61801, USA.
- The Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois, 61801, USA
| | | | - Kristin Martin
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois, 61801, USA.
| | - Rohit Bhargava
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois, 61801, USA.
- The Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois, 61801, USA
- Department of Bioengineering and Cancer Center at Illinois, University of Illinois Urbana-Champaign, Urbana, Illinois, 61801, USA
| | - Joaquín Rodríguez-López
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois, 61801, USA.
- The Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois, 61801, USA
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8
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Wu Y, Shi J, Kippin TE, Plaxco KW. Codeposition Enhances the Performance of Electrochemical Aptamer-Based Sensors. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:8703-8710. [PMID: 38616608 DOI: 10.1021/acs.langmuir.4c00585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Electrochemical aptamer-based (EAB) sensors, a minimally invasive means of performing high-frequency, real-time measurement of drugs and biomarkers in situ in the body, have traditionally been fabricated by depositing their target-recognizing aptamer onto an interrogating gold electrode using a "sequential" two-step method involving deposition of the thiol-modified oligonucleotide (typically for 1 h) followed by incubation in mercaptohexanol solution (typically overnight) to complete the formation of a stable, self-assembled monolayer. Here we use EAB sensors targeting vancomycin, tryptophan, and phenylalanine to show that "codeposition", a less commonly employed EAB fabrication method in which the thiol-modified aptamer and the mercaptohexanol diluent are deposited on the electrode simultaneously and for as little as 1 h, improves the signal gain (relative change in signal upon the addition of high concentrations of the target) of the vancomycin and tryptophan sensors without significantly reducing their stability. In contrast, the gain of the phenylalanine sensor is effectively identical irrespective of the fabrication approach employed. This sensor, however, appears to employ binding-induced displacement of the redox reporter rather than binding-induced folding as its signal transduction mechanism, suggesting in turn a mechanism for the improvement observed for the other two sensors. Codeposition thus not only provides a more convenient means of fabricating EAB sensors but also can improve their performance.
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Affiliation(s)
- Yuyang Wu
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Jinyuan Shi
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Tod E Kippin
- Department of Psychological and Brain Sciences, University of California Santa Barbara, Santa Barbara, California 93106, United States
- Department of Molecular Cellular and Developmental Biology, University of California, Santa Barbara, California 93106, United States
- Neuroscience Research Institute, University of California, Santa Barbara, California 93106, United States
- Biological Engineering Graduate Program, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Kevin W Plaxco
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
- Biological Engineering Graduate Program, University of California Santa Barbara, Santa Barbara, California 93106, United States
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9
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Wang Y, Duan H, Yalikun Y, Cheng S, Li M. A pendulum-type electrochemical aptamer-based sensor for continuous, real-time and stable detection of proteins. Talanta 2024; 266:125026. [PMID: 37544252 DOI: 10.1016/j.talanta.2023.125026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/27/2023] [Accepted: 08/01/2023] [Indexed: 08/08/2023]
Abstract
Continuous detection of proteins is crucial for health management and biomedical research. Electrochemical aptamer-based (E-AB) sensor that relies on binding affinity between a recognition oligonucleotide and its specific target is a versatile platform to fulfill this purpose. Yet, the vast majority of E-AB sensors are characterized by voltammetric methods, which suffer from signal drifts and low-frequency data acquisition during continuous operations. To overcome these limitations, we developed a novel E-AB sensor empowered by Gold nanoparticle-DNA Pendulum (GDP). Using chronoamperometric interrogation, the developed sensor enabled drift-resistant, high-frequency, and real-time monitoring of vascular endothelial growth factor (VEGF), a vital signaling protein that regulates angiogenesis, endothelial cell proliferation and vasculogenesis. We assembled VEGF aptamer-anchored GDP probes to a reduced graphene modified electrode, where a fast chronoamperometric current transient occurs as the GDP rapidly transport to the electrode surface. In the presence of target molecules, longer and concentration-dependent time decays were observed because of slower motion of the GDP in its bound state. After optimizing several decisive parameters, including composition ratios of GDP, probe density, and incubation time, the GDP empowered E-AB sensor achieves continuous, selective, and reversible monitoring of VEGF in both phosphate buffered saline (PBS) solutions and artificial urine with a wide detection range from 13 fM to 130 nM. Moreover, the developed sensor acquires signals on a millisecond timescale, and remains resistant to signal degradation during operation. This study offers a new approach to designing E-AB architectures for continuous biomolecular monitoring.
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Affiliation(s)
- Yizhou Wang
- School of Engineering, Macquarie University, Sydney, 2109, NSW, Australia
| | - Haowei Duan
- School of Engineering, Macquarie University, Sydney, 2109, NSW, Australia
| | - Yaxiaer Yalikun
- Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 630-0192, Ikoma, Japan
| | - Shaokoon Cheng
- School of Engineering, Macquarie University, Sydney, 2109, NSW, Australia
| | - Ming Li
- School of Engineering, Macquarie University, Sydney, 2109, NSW, Australia.
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10
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Weber CJ, Clay OM, Lycan RE, Anderson GK, Simoska O. Advances in electrochemical biosensor design for the detection of the stress biomarker cortisol. Anal Bioanal Chem 2024; 416:87-106. [PMID: 37989847 DOI: 10.1007/s00216-023-05047-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/30/2023] [Accepted: 11/08/2023] [Indexed: 11/23/2023]
Abstract
The monitoring of stress levels in humans has become increasingly relevant, given the recent incline of stress-related mental health disorders, lifestyle impacts, and chronic physiological diseases. Long-term exposure to stress can induce anxiety and depression, heart disease, and risky behaviors, such as drug and alcohol abuse. Biomarker molecules can be quantified in biological fluids to study human stress. Cortisol, specifically, is a hormone biomarker produced in the adrenal glands with biofluid concentrations that directly correlate to stress levels in humans. The rapid, real-time detection of cortisol is necessary for stress management and predicting the onset of psychological and physical ailments. Current methods, including mass spectrometry and immunoassays, are effective for sensitive cortisol quantification. However, these techniques provide only single measurements which pose challenges in the continuous monitoring of stress levels. Additionally, these analytical methods often require trained personnel to operate expensive instrumentation. Alternatively, low-cost electrochemical biosensors enable the real-time detection and continuous monitoring of cortisol levels while also providing adequate analytical figures of merit (e.g., sensitivity, selectivity, sensor response times, detection limits, and reproducibility) in a simple design platform. This review discusses the recent developments in electrochemical biosensor design for the detection of cortisol in human biofluids. Special emphasis is given to biosensor recognition elements, including antibodies, molecularly imprinted polymers (MIPs), and aptamers, as critical components of electrochemical biosensors for cortisol detection. Furthermore, the advantages and limiting factors of various electrochemical techniques and sensing in complex biofluid matrices are overviewed. Remarks on the current challenges and future perspectives regarding electrochemical biosensors for stress monitoring are provided, including matrix effects (pH dependence and biological interferences), wearability, and large-scale production.
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Affiliation(s)
- Courtney J Weber
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Olivia M Clay
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Reese E Lycan
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Gracie K Anderson
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Olja Simoska
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA.
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11
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Watkins Z, McHenry A, Heikenfeld J. Wearing the Lab: Advances and Challenges in Skin-Interfaced Systems for Continuous Biochemical Sensing. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2024; 187:223-282. [PMID: 38273210 DOI: 10.1007/10_2023_238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2024]
Abstract
Continuous, on-demand, and, most importantly, contextual data regarding individual biomarker concentrations exemplify the holy grail for personalized health and performance monitoring. This is well-illustrated for continuous glucose monitoring, which has drastically improved outcomes and quality of life for diabetic patients over the past 2 decades. Recent advances in wearable biosensing technologies (biorecognition elements, transduction mechanisms, materials, and integration schemes) have begun to make monitoring of other clinically relevant analytes a reality via minimally invasive skin-interfaced devices. However, several challenges concerning sensitivity, specificity, calibration, sensor longevity, and overall device lifetime must be addressed before these systems can be made commercially viable. In this chapter, a logical framework for developing a wearable skin-interfaced device for a desired application is proposed with careful consideration of the feasibility of monitoring certain analytes in sweat and interstitial fluid and the current development of the tools available to do so. Specifically, we focus on recent advancements in the engineering of biorecognition elements, the development of more robust signal transduction mechanisms, and novel integration schemes that allow for continuous quantitative analysis. Furthermore, we highlight the most compelling and promising prospects in the field of wearable biosensing and the challenges that remain in translating these technologies into useful products for disease management and for optimizing human performance.
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Affiliation(s)
- Zach Watkins
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA.
| | - Adam McHenry
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA
| | - Jason Heikenfeld
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA
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12
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Nguyen MD, Nguyen KN, Malo S, Banerjee I, Wu D, Du-Thumm L, Dauphin-Ducharme P. Electrochemical Aptamer-Based Biosensors for Measurements in Undiluted Human Saliva. ACS Sens 2023; 8:4625-4635. [PMID: 37992319 DOI: 10.1021/acssensors.3c01624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2023]
Abstract
Although blood remains a gold standard diagnostic fluid for most health exams, it involves an unpleasant and relatively invasive sampling procedure (finger pricking or venous draw). Saliva contains many relevant and useful biomarkers for diagnostic purposes, and its collection, in contrast, is noninvasive and can be obtained with minimal effort. Current saliva analyses are, however, achieved using chromatography or lateral flow assays, which, despite their high accuracy and sensitivity, can demand expensive laboratory-based instruments operated by trained personnel or offer only semiquantitative results. In response, we investigated electrochemical aptamer-based (E-AB) biosensors, a reagentless sensing platform, to allow for continuous and real-time measurements directly in undiluted, unstimulated human whole saliva. As a proof-of-concept study, we developed E-AB biosensors capable of detecting low-molecular-weight analytes (glucose and adenosine monophosphate (AMP)). To our knowledge, we report the first E-AB sensor for glucose, an approach that is inherently independent of its chemical reactivity in contrast to home glucometers. For these three sensors, we evaluated their figures of merits, stability, and reusability over short- and long-term exposure directly in saliva. In doing so, we found that E-AB sensors allow rapid and convenient molecular measurements in whole saliva with unprecedented sensitivities in the pico- to nanomolar regime and could be regenerated and reused up to 7 days when washed and stored in phosphate-buffered saline at room temperature. We envision that salivary molecular measurements using E-AB sensors are a promising alternative to invasive techniques and can be used for improved point-of-care clinical diagnosis and at-home measurements.
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Affiliation(s)
- Minh-Dat Nguyen
- Département de chimie, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
| | - Khoa-Nam Nguyen
- Département de chimie, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
| | - Samuel Malo
- Département de chimie, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
| | - Indrani Banerjee
- Colgate, Research and Development Center, Piscataway, New Jersey 08854, United States
| | - Donghui Wu
- Colgate, Research and Development Center, Piscataway, New Jersey 08854, United States
| | - Laurence Du-Thumm
- Colgate, Research and Development Center, Piscataway, New Jersey 08854, United States
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13
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Dominique NL, Chandran A, Jensen IM, Jenkins DM, Camden JP. Unmasking the Electrochemical Stability of N-Heterocyclic Carbene Monolayers on Gold. Chemistry 2023:e202303681. [PMID: 38116819 DOI: 10.1002/chem.202303681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 12/16/2023] [Indexed: 12/21/2023]
Abstract
N-heterocyclic carbene (NHC) monolayers are transforming electrocatalysis and biosensor design via their increased performance and stability. Despite their increasing use in electrochemical systems, the integrity of the NHC monolayer during voltage perturbations remains largely unknown. Herein, we deploy surface-enhanced Raman spectroscopy (SERS) to measure the stability of two model NHCs on gold in ambient conditions as a function of applied potential and under continuous voltammetric interrogation. Our results illustrate that NHC monolayers exhibit electrochemical stability over a wide voltage window (-1 V to 0.5 V vs Ag|AgCl), but they are found to degrade at strongly reducing (< -1 V) or oxidizing (>0.5 V) potentials. We also address NHC monolayer stability under continuous voltammetric interrogation between 0.2 V and -0.5 V, a commonly used voltage window for sensing, showing they are stable for up to 43 hours. However, we additionally find that modifications of the backbone NHC structure can lead to significantly shorter operational lifetimes. While these results highlight the potential of NHC architectures for electrode functionalization, they also reveal potential pitfalls that have not been fully appreciated in electrochemical applications of NHCs.
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Affiliation(s)
- Nathaniel L Dominique
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN-46556, United States
| | - Aruna Chandran
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN-46556, United States
| | - Isabel M Jensen
- Department of Chemistry, University of Tennessee, Knoxville, Knoxville, TN-37996
| | - David M Jenkins
- Department of Chemistry, University of Tennessee, Knoxville, Knoxville, TN-37996
| | - Jon P Camden
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN-46556, United States
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14
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Li Z, Lv Y, Duan X, Liu B, Zhao Y. Highly Uniform DNA Monolayers Generated by Freezing-Directed Assembly on Gold Surfaces Enable Robust Electrochemical Sensing in Whole Blood. Angew Chem Int Ed Engl 2023; 62:e202312975. [PMID: 37726209 DOI: 10.1002/anie.202312975] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 09/17/2023] [Accepted: 09/18/2023] [Indexed: 09/21/2023]
Abstract
Assembling DNA on solid surfaces is fundamental to surface-based DNA technology. However, precise control over DNA conformation and organization at solid-liquid interfaces remains a challenge, resulting in limited stability and sensitivity in biosensing applications. We herein communicate a simple and robust method for creating highly uniform DNA monolayers on gold surfaces by a freeze-thawing process. Using Raman spectroscopy, fluorescent imaging, and square wave voltammetry, we demonstrate that thiolated DNA is concentrated and immobilized on gold surfaces with an upright conformation. Moreover, our results reveal that the freezing-induced DNA surfaces are more uniform, leading to improved DNA stability and target recognition. Lastly, we demonstrate the successful detection of a model drug in undiluted whole blood while mitigating the effects of biofouling. Our work not only provides a simple approach to tailor the DNA-gold surface for biosensors but also sheds light on the unique behavior of DNA oligonucleotides upon freezing on the liquid-solid interface.
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Affiliation(s)
- Zhenglian Li
- Institute of Analytical Chemistry and Instrument for Life Science, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, P. R. China
| | - Yanguan Lv
- Institute of Analytical Chemistry and Instrument for Life Science, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, P. R. China
- Department of Clinical Medical Laboratory, Affiliated Hospital of Yang Zhou University Medical College, Huai'an Maternal and Child Health Care Center, Huai'an, Jiangsu, 223002, P. R. China
| | - Xiaoman Duan
- Institute of Analytical Chemistry and Instrument for Life Science, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, P. R. China
| | - Biwu Liu
- Institute of Analytical Chemistry and Instrument for Life Science, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, P. R. China
| | - Yongxi Zhao
- Institute of Analytical Chemistry and Instrument for Life Science, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, P. R. China
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, P. R. China
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15
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Son K, Uzawa T, Ito Y, Kippin T, Plaxco KW, Fujie T. Survey of oligoethylene glycol-based self-assembled monolayers on electrochemical aptamer-based sensor in biological fluids. Biochem Biophys Res Commun 2023; 668:1-7. [PMID: 37230045 DOI: 10.1016/j.bbrc.2023.05.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 04/26/2023] [Accepted: 05/10/2023] [Indexed: 05/27/2023]
Abstract
The ability to monitor levels of endogenous markers and clearance profiles of drugs and their metabolites can improve the quality of biomedical research and precision with which therapies are individualized. Towards this end, electrochemical aptamer-based (EAB) sensors have been developed that support the real-time monitoring of specific analytes in vivo with clinically relevant specificity and sensitivity. A challenge associated with the in vivo deployment of EAB sensors, however, is how to manage the signal drift which, although correctable, ultimately leads to unacceptably low signal-to-noise ratios, limiting the measurement duration. Motivated by the correction of signal drift, in this paper, we have explored the use of oligoethylene glycol (OEG), a widely employed antifouling coating, to reduce the signal drift in EAB sensors. Counter to expectations, however, when challenged in 37 °C whole blood in vitro, EAB sensors employing OEG-modified self-assembled monolayers exhibit both greater drift and reduced signal gain, compared with those employ a simple, hydroxyl-terminated monolayer. On the other hand, when EAB sensor was prepared with a mix monolayer using MCH and lipoamido OEG 2 alcohol, reduced signal noise was observed compared to the same sensor prepared with MCH presumably due to improved SAM construction. These results suggest broader exploration of antifouling materials will be required to improve the signal drift of EAB sensors.
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Affiliation(s)
- Kon Son
- School of Life Science and Technology, Tokyo Institute of Technology, B-50, Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan; RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Takanori Uzawa
- RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan; RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Yoshihiro Ito
- RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan; RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Tod Kippin
- Department of Psychological and Brain Sciences, UCSB, Santa Barbara, CA, 93106, USA
| | - Kevin W Plaxco
- Department of Chemistry and Biochemistry, UCSB, Santa Barbara, CA, 93106, USA
| | - Toshinori Fujie
- School of Life Science and Technology, Tokyo Institute of Technology, B-50, Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan; RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan; Living Systems Materialogy (LiSM) Research Group, International Research Frontiers Initiative (IRFI), Tokyo Institute of Technology, B-50, Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan.
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16
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Pellitero M, Jensen IM, Dominique NL, Ekowo LC, Camden JP, Jenkins DM, Arroyo-Currás N. Stability of N-Heterocyclic Carbene Monolayers under Continuous Voltammetric Interrogation. ACS APPLIED MATERIALS & INTERFACES 2023; 15:35701-35709. [PMID: 37449918 PMCID: PMC10377464 DOI: 10.1021/acsami.3c06148] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 06/28/2023] [Indexed: 07/18/2023]
Abstract
N-Heterocyclic carbenes (NHCs) are promising monolayer-forming ligands that can overcome limitations of thiol-based monolayers in terms of stability, surface functionality, and reactivity across a variety of transition-metal surfaces. Recent publications have reported the ability of NHCs to support biomolecular receptors on gold substrates for sensing applications and improved tolerance to prolonged biofluid exposure relative to thiols. However, important questions remain regarding the stability of these monolayers when subjected to voltage perturbations, which is needed for applications with electrochemical platforms. Here, we investigate the ability of two NHCs, 1,3-diisopropylbenzimidazole and 5-(ethoxycarbonyl)-1,3-diisopropylbenzimidazole, to form monolayers via self-assembly from methanolic solutions of their trifluoromethanesulfonate salts. We compare the electrochemical behavior of the resulting monolayers relative to that of benchmark mercaptohexanol monolayers in phosphate-buffered saline. Within the -0.15 to 0.25 V vs Ag|AgCl voltage window, NHC monolayers are stable on gold surfaces, wherein they electrochemically perform like thiol-based monolayers and undergo similar reorganization kinetics, displaying long-term stability under incubation in buffered media and under continuous voltammetric interrogation. At negative voltages, NHC monolayers cathodically desorb from the electrode surface at lower bias (-0.1 V) than thiol-based monolayers (-0.5 V). At voltages more positive than 0.25 V, NHC monolayers anodically desorb from electrode surfaces at similar voltages to thiol-based monolayers. These results highlight new limitations to NHC monolayer stability imposed by electrochemical interrogation of the underlying gold electrodes. Our results serve as a framework for future optimization of NHC monolayers on gold for electrochemical applications, as well as structure-functionality studies of NHCs on gold.
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Affiliation(s)
- Miguel
Aller Pellitero
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Isabel M. Jensen
- Department
of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Nathaniel L. Dominique
- Department
of Chemistry and Biochemistry, University
of Notre Dame, Notre
Dame, Indiana 46556, United States
| | - Lilian Chinenye Ekowo
- Department
of Chemistry and Biochemistry, University
of Notre Dame, Notre
Dame, Indiana 46556, United States
| | - Jon P. Camden
- Department
of Chemistry and Biochemistry, University
of Notre Dame, Notre
Dame, Indiana 46556, United States
| | - David M. Jenkins
- Department
of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Netzahualcóyotl Arroyo-Currás
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
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17
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Young T, Clark V, Arroyo-Currás N, Heikenfeld J. Perspective-The Feasibility of Continuous Protein Monitoring in Interstitial Fluid. ECS SENSORS PLUS 2023; 2:027001. [PMID: 37128505 PMCID: PMC10140668 DOI: 10.1149/2754-2726/accd7e] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/09/2023] [Indexed: 05/03/2023]
Abstract
Real-time continuous monitoring of proteins in-vivo holds great potential for personalized medical applications. Unfortunately, a prominent knowledge gap exists in the fundamental biology regarding protein transfer and correlation between interstitial fluid and blood. Additionally, technological sensing will require affinity-based platforms that cannot be robustly protected in-vivo and will therefore be challenged in sensitivity, longevity, and fouling over multi-day to week timelines. Here we use electrochemical aptamer sensors as a model system to discuss further research necessary to achieve continuous protein sensing.
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Affiliation(s)
- Thomas Young
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH 45221, United States of America
| | - Vincent Clark
- Chemistry-Biology Interface Program, Zanvyl Krieger School of Arts & Sciences, Johns Hopkins University, Baltimore, MD 21218, United States of America
| | - Netzahualcóyotl Arroyo-Currás
- Chemistry-Biology Interface Program, Zanvyl Krieger School of Arts & Sciences, Johns Hopkins University, Baltimore, MD 21218, United States of America
| | - Jason Heikenfeld
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH 45221, United States of America
- Department of Electrical & Computer Engineering, University of Cincinnati, Cincinnati, OH 45221, United States of America
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States of America
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18
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Szunerits S, Pagneux Q, M'Barek YB, Vassal S, Boukherroub R. Do not let electrode fouling be the enemy of bioanalysis. Bioelectrochemistry 2023; 153:108479. [PMID: 37329846 DOI: 10.1016/j.bioelechem.2023.108479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 05/19/2023] [Accepted: 05/24/2023] [Indexed: 06/19/2023]
Abstract
Electrochemical biosensors are one of the best choices for the sensing of biomarkers due to their high performance, low cost, miniaturization, and wide applicability. However, like for any sensing process, electrode fouling affects severely the analytical performance of the sensor, such as sensitivity, detection limit, reproducibility, and overall reliability. Fouling arises from nonspecific adsorption of different components present in the sensing medium and in particular in complex biofluids such as full blood. The complex composition of blood where biomarkers are present at extremely low concentrations compared to the rest of the fluid composition makes electrochemical biosensing challenging. Direct biomarker analysis within full blood samples remains however central for the future development in electrochemical-based diagnostics. Herein, we aim to provide short discussion of past and more recent strategies and concepts employed to diminish background noise due to surface fouling and overcome current hurdles for the implementation and commercialisation of electrochemical-based biosensors for medical diagnostics of protein biomarkers in a point of care format.
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Affiliation(s)
- Sabine Szunerits
- Univ. Lille, CNRS, Centrale Lille, Univ. Polytechnique Hauts-de-France, UMR 8520 - IEMN, F-59000 Lille, France
| | - Quentin Pagneux
- Univ. Lille, CNRS, Centrale Lille, Univ. Polytechnique Hauts-de-France, UMR 8520 - IEMN, F-59000 Lille, France
| | | | - Simon Vassal
- Linxens France, 37 rue des Closeaux, 78200 Mantes-la-Jolie, France
| | - Rabah Boukherroub
- Univ. Lille, CNRS, Centrale Lille, Univ. Polytechnique Hauts-de-France, UMR 8520 - IEMN, F-59000 Lille, France
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19
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Watkins Z, Karajic A, Young T, White R, Heikenfeld J. Week-Long Operation of Electrochemical Aptamer Sensors: New Insights into Self-Assembled Monolayer Degradation Mechanisms and Solutions for Stability in Serum at Body Temperature. ACS Sens 2023; 8:1119-1131. [PMID: 36884003 PMCID: PMC10443649 DOI: 10.1021/acssensors.2c02403] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Abstract
Conventional wisdom suggests that widely utilized self-assembled alkylthiolate monolayers on gold are too unstable to last more than several days when exposed to complex fluids such as raw serum at body temperature. Demonstrated here is that these monolayers can not only last at least 1 week under such harsh conditions but that significant applied value can be captured for continuous electrochemical aptamer biosensors. Electrochemical aptamer biosensors provide an ideal tool to investigate monolayer degradation, as aptamer sensors require a tightly packed monolayer to preserve sensor signal vs background current and readily reveal fouling by albumin and other solutes when operating in biofluids. Week-long operation in serum at 37 °C is achieved by (1) increasing van der Waals interactions between adjacent monolayer molecules to increase the activation energy required for desorption, (2) optimizing electrochemical measurement to decrease both alkylthiolate oxidation and electric-field-induced desorption, and (3) mitigating fouling using protective zwitterionic membranes and zwitterion-based blocking layers with antifouling properties. This work further proposes origins and mechanisms of monolayer degradation in a logical stepwise manner that was previously unobservable over multiday time scales. Several of the observed results are surprising, revealing that short-term improvements to sensor longevity (i.e., hours) actually increase sensor degradation in the longer term (i.e., days). The results and underlying insights on mechanisms not only push forward fundamental understanding of stability for self-assembled monolayers but also demonstrate an important milestone for continuous electrochemical aptamer biosensors.
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Affiliation(s)
- Zach Watkins
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH 45221
- Medical Scientist Training Program, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Aleksandar Karajic
- Department of Electrical & Computer Engineering, University of Cincinnati, Cincinnati, OH 45221
| | - Thomas Young
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH 45221
| | - Ryan White
- Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221
- Department of Electrical & Computer Engineering, University of Cincinnati, Cincinnati, OH 45221
| | - Jason Heikenfeld
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH 45221
- Department of Electrical & Computer Engineering, University of Cincinnati, Cincinnati, OH 45221
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20
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Clark V, Pellitero MA, Arroyo-Currás N. Explaining the Decay of Nucleic Acid-Based Sensors under Continuous Voltammetric Interrogation. Anal Chem 2023; 95:4974-4983. [PMID: 36881708 PMCID: PMC10035425 DOI: 10.1021/acs.analchem.2c05158] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 02/23/2023] [Indexed: 03/09/2023]
Abstract
Nucleic acid-based electrochemical sensors (NBEs) can support continuous and highly selective molecular monitoring in biological fluids, both in vitro and in vivo, via affinity-based interactions. Such interactions afford a sensing versatility that is not supported by strategies that depend on target-specific reactivity. Thus, NBEs have significantly expanded the scope of molecules that can be monitored continuously in biological systems. However, the technology is limited by the lability of the thiol-based monolayers employed for sensor fabrication. Seeking to understand the main drivers of monolayer degradation, we studied four possible mechanisms of NBE decay: (i) passive desorption of monolayer elements in undisturbed sensors, (ii) voltage-induced desorption under continuous voltammetric interrogation, (iii) competitive displacement by thiolated molecules naturally present in biofluids like serum, and (iv) protein binding. Our results indicate that voltage-induced desorption of monolayer elements is the main mechanism by which NBEs decay in phosphate-buffered saline. This degradation can be overcome by using a voltage window contained between -0.2 and 0.2 V vs Ag|AgCl, reported for the first time in this work, where electrochemical oxygen reduction and surface gold oxidation cannot occur. This result underscores the need for chemically stable redox reporters with more positive reduction potentials than the benchmark methylene blue and the ability to cycle thousands of times between redox states to support continuous sensing for long periods. Additionally, in biofluids, the rate of sensor decay is further accelerated by the presence of thiolated small molecules like cysteine and glutathione, which can competitively displace monolayer elements even in the absence of voltage-induced damage. We hope that this work will serve as a framework to inspire future development of novel sensor interfaces aiming to eliminate the mechanisms of signal decay in NBEs.
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Affiliation(s)
- Vincent Clark
- Chemistry-Biology
Interface Program, Zanvyl Krieger School of Arts & Sciences, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Miguel Aller Pellitero
- Departamento
de Química Física y Analítica, Universidad de Oviedo, Av. Julián Clavería 8, Oviedo 33006, Spain
- Instituto
de Investigación Sanitaria Del Principado de Asturias, Avenida de Roma, Oviedo 33011, Spain
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Netzahualcóyotl Arroyo-Currás
- Chemistry-Biology
Interface Program, Zanvyl Krieger School of Arts & Sciences, Johns Hopkins University, Baltimore, Maryland 21218, United States
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
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21
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Williamson P, Piskunen P, Ijäs H, Butterworth A, Linko V, Corrigan DK. Signal Amplification in Electrochemical DNA Biosensors Using Target-Capturing DNA Origami Tiles. ACS Sens 2023; 8:1471-1480. [PMID: 36914224 PMCID: PMC10152479 DOI: 10.1021/acssensors.2c02469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
Electrochemical DNA (e-DNA) biosensors are feasible tools for disease monitoring, with their ability to translate hybridization events between a desired nucleic acid target and a functionalized transducer, into recordable electrical signals. Such an approach provides a powerful method of sample analysis, with a strong potential to generate a rapid time to result in response to low analyte concentrations. Here, we report a strategy for the amplification of electrochemical signals associated with DNA hybridization, by harnessing the programmability of the DNA origami method to construct a sandwich assay to boost charge transfer resistance (RCT) associated with target detection. This allowed for an improvement in the sensor limit of detection by two orders of magnitude compared to a conventional label-free e-DNA biosensor design and linearity for target concentrations between 10 pM and 1 nM without the requirement for probe labeling or enzymatic support. Additionally, this sensor design proved capable of achieving a high degree of strand selectivity in a challenging DNA-rich environment. This approach serves as a practical method for addressing strict sensitivity requirements necessary for a low-cost point-of-care device.
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Affiliation(s)
- Paul Williamson
- Department of Biomedical Engineering, University of Strathclyde, Glasgow G1 1QE, United Kingdom
| | - Petteri Piskunen
- Biohybrid Materials, Department of Bioproducts and Biosystems, Aalto University, 00076 Aalto, Finland
| | - Heini Ijäs
- Biohybrid Materials, Department of Bioproducts and Biosystems, Aalto University, 00076 Aalto, Finland.,Ludwig-Maximilians-University, Geschwister-Scholl-Platz 1, 80539 Munich, Germany
| | - Adrian Butterworth
- Department of Biomedical Engineering, University of Strathclyde, Glasgow G1 1QE, United Kingdom
| | - Veikko Linko
- Biohybrid Materials, Department of Bioproducts and Biosystems, Aalto University, 00076 Aalto, Finland.,LIBER Center of Excellence, Aalto University, 00076 Aalto, Finland.,Institute of Technology, University of Tartu, Nooruse 1, 50411 Tartu, Estonia
| | - Damion K Corrigan
- Department of Biomedical Engineering, University of Strathclyde, Glasgow G1 1QE, United Kingdom.,Department of Pure & Applied Chemistry, Thomas Graham Building, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, United Kingdom
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22
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Shaver A, Arroyo-Currás N. Expanding the Monolayer Scope for Nucleic Acid-Based Electrochemical Sensors Beyond Thiols on Gold: Alkylphosphonic Acids on ITO. ECS SENSORS PLUS 2023; 2:010601. [PMID: 37006966 PMCID: PMC10053865 DOI: 10.1149/2754-2726/acc4d9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/15/2023] [Indexed: 03/18/2023]
Abstract
Electrochemical biosensors are a powerful and rapidly evolving molecular monitoring technology. Evidenced by the success of the continuous glucose monitor in managing Type 1 Diabetes, these sensors are capable of precise, accurate measurements in unprocessed biological environments. Nucleic acid-based electrochemical sensors (NBEs) are a specific type of biosensor that employs the target binding and conformational dynamics of nucleic acids for signal transduction. Currently, the vast majority of NBEs are fabricated via self-assembly of alkylthiols on Au electrodes. However, this architecture is limited in scope, as Au electrodes are not universally deployable for all potential NBE applications. Here, to expand the repertoire of materials on which NBEs can be made, we describe the multistep procedure for creating sensing monolayers of alkylphosphonic acids on a conductive oxide surface. Using such monolayers on indium tin oxide (ITO)-coated glass slides, we couple redox reporter-modified nucleic acids and demonstrate signaling of procaine-binding NBE sensors in buffer and human serum. We investigate the operational stability of these NBE sensors to reveal faster signal loss relative to benchmark thiol-on-gold sensing layers, a result that arises due to poor stability of the underlying ITO. Finally, we discuss future directions to continue expansion of NBE sensor materials and applications.
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Affiliation(s)
- Alexander Shaver
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21202, United States of America
| | - Netzahualcóyotl Arroyo-Currás
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21202, United States of America
- Department of Chemical and Biomolecular Engineering and Institute for NanoBioTechnology, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States of America
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23
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Aller Pellitero M, Kundu N, Sczepanski J, Arroyo-Currás N. Os(II/III) complex supports pH-insensitive electrochemical DNA-based sensing with superior operational stability than the benchmark methylene blue reporter. Analyst 2023; 148:806-813. [PMID: 36632808 PMCID: PMC9924220 DOI: 10.1039/d2an01901a] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
DNA-based electrochemical sensors use redox reporters to transduce affinity events into electrical currents. Ideally, such reporters must be electrochemically reversible, chemically stable for thousands of redox cycles, and tolerant to changing chemical environments. Here we report the first use of an Os(II/III) complex in DNA-based sensors, which undergoes pH-insensitive electron transfer with 35% better operational stability relative to the benchmark methylene blue, making it a promising reporter for continuous molecular monitoring applications where pH fluctuates with time.
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Affiliation(s)
- Miguel Aller Pellitero
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, USA.
| | - Nandini Kundu
- Department of Chemistry, Texas A&M UniversityCollege StationTX 77843USA
| | | | - Netzahualcóyotl Arroyo-Currás
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, USA. .,Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, 21218, USA
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24
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Khuda N, Somasundaram S, Urgunde AB, Easley CJ. Ionic Strength and Hybridization Position near Gold Electrodes Can Significantly Improve Kinetics in DNA-Based Electrochemical Sensors. ACS APPLIED MATERIALS & INTERFACES 2023; 15:5019-5027. [PMID: 36661270 PMCID: PMC10370289 DOI: 10.1021/acsami.2c22741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
A variety of electrochemical (EC) biosensors play critical roles in disease diagnostics. More recently, DNA-based EC sensors have been established as promising for detecting a wide range of analyte classes. Since most of these sensors rely on the high specificity of DNA hybridization for analyte binding or structural control, it is crucial to understand the kinetics of hybridization at the electrode surface. In this work, we have used methylene blue-labeled DNA strands to monitor the kinetics of DNA hybridization at the electrode surface with square-wave voltammetry. By varying the position of the double-stranded DNA segment relative to the electrode surface as well as the bulk solution's ionic strength (0.125-1.00 M), we observed significant interferences with DNA hybridization closer to the surface, with more substantial interference at lower ionic strength. As a demonstration of the effect, toehold-mediated strand displacement reactions were slowed and diminished close to the surface, while strategic placement of the DNA binding site improved reaction rates and yields. This work manifests that both the salt concentration and DNA hybridization site relative to the electrode are important factors to consider when designing DNA-based EC sensors that measure hybridization directly at the electrode surface.
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Affiliation(s)
- Niamat Khuda
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849, USA
| | | | - Ajay B. Urgunde
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849, USA
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25
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Kesler V, Fu K, Chen Y, Park CH, Eisenstein M, Murmann B, Soh HT. Tailoring electrode surface charge to achieve discrimination and quantification of chemically similar small molecules with electrochemical aptamers. ADVANCED FUNCTIONAL MATERIALS 2023; 33:2208534. [PMID: 36819738 PMCID: PMC9937077 DOI: 10.1002/adfm.202208534] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Indexed: 06/18/2023]
Abstract
Electrochemical biosensors based on structure-switching aptamers offer many advantages because they can operate directly in complex samples and offer the potential to integrate with miniaturized electronics. Unfortunately, these biosensors often suffer from cross-reactivity problems when measuring a target in samples containing other chemically similar molecules, such as precursors or metabolites. While some progress has been made in selecting highly specific aptamers, the discovery of these reagents remains slow and costly. In this work, we demonstrate a novel strategy to distinguish molecules with miniscule difference in chemical composition (such as a single hydroxyl group) - with cross reactive aptamer probes - by tuning the charge state of the surface on which the aptamer probes are immobilized. As an exemplar, we show that our strategy can distinguish between DOX and many structurally similar analytes, including its primary metabolite doxorubicinol (DOXol). We then demonstrate the ability to accurately quantify mixtures of these two molecules based on their differential response to sensors with different surface-charge properties. We believe this methodology is general and can be extended to a broad range of applications.
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Affiliation(s)
- Vladimir Kesler
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA
- Department of Radiology, Stanford University, Stanford, CA 94305, USA
| | - Kaiyu Fu
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA
- Department of Radiology, Stanford University, Stanford, CA 94305, USA
| | - Yihang Chen
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Chan Ho Park
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA
- Department of Radiology, Stanford University, Stanford, CA 94305, USA
| | - Michael Eisenstein
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Boris Murmann
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA
| | - H. Tom Soh
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA
- Department of Radiology, Stanford University, Stanford, CA 94305, USA
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
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26
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Shafique H, de Vries J, Strauss J, Khorrami Jahromi A, Siavash Moakhar R, Mahshid S. Advances in the Translation of Electrochemical Hydrogel-Based Sensors. Adv Healthc Mater 2023; 12:e2201501. [PMID: 36300601 DOI: 10.1002/adhm.202201501] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 09/26/2022] [Indexed: 02/03/2023]
Abstract
Novel biomaterials for bio- and chemical sensing applications have gained considerable traction in the diagnostic community with rising trends of using biocompatible and lowly cytotoxic material. Hydrogel-based electrochemical sensors have become a promising candidate for their swellable, nano-/microporous, and aqueous 3D structures capable of immobilizing catalytic enzymes, electroactive species, whole cells, and complex tissue models, while maintaining tunable mechanical properties in wearable and implantable applications. With advances in highly controllable fabrication and processability of these novel biomaterials, the possibility of bio-nanocomposite hydrogel-based electrochemical sensing presents a paradigm shift in the development of biocompatible, "smart," and sensitive health monitoring point-of-care devices. Here, recent advances in electrochemical hydrogels for the detection of biomarkers in vitro, in situ, and in vivo are briefly reviewed to demonstrate their applicability in ideal conditions, in complex cellular environments, and in live animal models, respectively, to provide a comprehensive assessment of whether these biomaterials are ready for point-of-care translation and biointegration. Sensors based on conductive and nonconductive polymers are presented, with highlights of nano-/microstructured electrodes that provide enhanced sensitivity and selectivity in biocompatible matrices. An outlook on current challenges that shall be addressed for the realization of truly continuous real-time sensing platforms is also presented.
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Affiliation(s)
- Houda Shafique
- Department of Bioengineering, McGill University, Montreal, QC, H3A 0E9, Canada
| | - Justin de Vries
- Department of Bioengineering, McGill University, Montreal, QC, H3A 0E9, Canada
| | - Julia Strauss
- Department of Bioengineering, McGill University, Montreal, QC, H3A 0E9, Canada
| | | | | | - Sara Mahshid
- Department of Bioengineering, McGill University, Montreal, QC, H3A 0E9, Canada
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27
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Shaver A, Mahlum J, Scida K, Johnston ML, Aller Pellitero M, Wu Y, Carr GV, Arroyo-Currás N. Optimization of Vancomycin Aptamer Sequence Length Increases the Sensitivity of Electrochemical, Aptamer-Based Sensors In Vivo. ACS Sens 2022; 7:3895-3905. [PMID: 36417705 PMCID: PMC9791989 DOI: 10.1021/acssensors.2c01910] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/14/2022] [Indexed: 11/24/2022]
Abstract
The measurement of serum vancomycin levels at the clinic is critical to optimizing dosing given the narrow therapeutic window of this antibiotic. Current approaches to quantitate serum vancomycin levels are based on immunoassays, which are multistep methods requiring extensive processing of patient samples. As an alternative, vancomycin-binding electrochemical, aptamer-based sensors (E-ABs) were developed to simplify the workflow of vancomycin monitoring. E-ABs enable the instantaneous measurement of serum vancomycin concentrations without the need for sample dilution or other processing steps. However, the originally reported vancomycin-binding E-ABs had a dissociation constant of 45 μM, which is approximately 1 order of magnitude higher than the recommended trough concentrations of vancomycin measured in patients. This limited sensitivity hinders the ability of E-ABs to accurately support vancomycin monitoring. To overcome this problem, here we sought to optimize the length of the vancomycin-binding aptamer sequence to enable a broader dynamic range in the E-AB platform. Our results demonstrate, via isothermal calorimetry and E-AB calibrations in undiluted serum, that superior affinity and near-equal sensor gain in vitro can be achieved using a one-base-pair-longer aptamer than the truncated sequence originally reported. We validate the impact of the improved binding affinity in vivo by monitoring vancomycin levels in the brain cortex of live mice following intravenous administration. While the original sequence fails to resolve vancomycin concentrations from baseline noise (SNR = 1.03), our newly reported sequence provides an SNR of 1.62 at the same dose.
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Affiliation(s)
- Alexander Shaver
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - J.D. Mahlum
- Chemistry-Biology
Interface Program, Zanvyl Krieger School of Arts & Sciences, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Karen Scida
- Lieber
Institute for Brain Development, Johns Hopkins
University School of Medicine, Baltimore, Maryland 21205, United States
| | - Melanie L. Johnston
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- Biochemistry,
Cellular and Molecular Biology, Johns Hopkins
University School of Medicine, Baltimore, Maryland 21287, United States
| | - Miguel Aller Pellitero
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Yao Wu
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Gregory V. Carr
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- Lieber
Institute for Brain Development, Johns Hopkins
University School of Medicine, Baltimore, Maryland 21205, United States
| | - Netzahualcóyotl Arroyo-Currás
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- Chemistry-Biology
Interface Program, Zanvyl Krieger School of Arts & Sciences, Johns Hopkins University, Baltimore, Maryland 21218, United States
- Biochemistry,
Cellular and Molecular Biology, Johns Hopkins
University School of Medicine, Baltimore, Maryland 21287, United States
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28
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Downs AM, Plaxco KW. Real-Time, In Vivo Molecular Monitoring Using Electrochemical Aptamer Based Sensors: Opportunities and Challenges. ACS Sens 2022; 7:2823-2832. [PMID: 36205360 PMCID: PMC9840907 DOI: 10.1021/acssensors.2c01428] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The continuous, real-time measurement of specific molecules in situ in the body would greatly improve our ability to understand, diagnose, and treat disease. The vast majority of continuous molecular sensing technologies, however, either (1) rely on the chemical or enzymatic reactivity of their targets, sharply limiting their scope, or (2) have never been shown (and likely will never be shown) to operate in the complex environments found in vivo. Against this background, here we review electrochemical aptamer-based (EAB) sensors, an electrochemical approach to real-time molecular monitoring that has now seen 15 years of academic development. The strengths of the EAB platform are significant: to date it is the only molecular measurement technology that (1) functions independently of the chemical reactivity of its targets, and is thus general, and (2) supports in vivo measurements. Specifically, using EAB sensors we, and others, have already reported the real-time, seconds-resolved measurements of multiple, unrelated drugs and metabolites in situ in the veins and tissues of live animals. Against these strengths, we detail the platform's remaining weaknesses, which include still limited measurement duration (hours, rather than the more desirable days) and the difficulty in obtaining sufficiently high performance aptamers against new targets, before then detailing promising approaches overcoming these hurdles. Finally, we close by exploring the opportunities we believe this potentially revolutionary technology (as well as a few, possibly competing, technologies) will create for both researchers and clinicians.
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Affiliation(s)
- Alex M. Downs
- Sandia National Laboratories, Albuquerque, NM 87106, USA
| | - Kevin W. Plaxco
- Center for Bioengineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA,Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, CA 93106, USA,Corresponding author:
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29
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Zhang Z, Wang Y, Mei Z, Wang Y, Li H, Li S, Xia F. Incorporating Hydrophobic Moieties into Self-Assembled Monolayers to Enable Electrochemical Aptamer-Based Sensors Deployed Directly in a Complex Matrix. ACS Sens 2022; 7:2615-2624. [PMID: 35998663 DOI: 10.1021/acssensors.2c00995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Continuous real-time measurement of specific targets in complex biological samples is of great significance for early diagnosis and treatment of diseases and thus enables achievement of personalized medicine. Electrochemical aptamer-based (E-AB) sensors are good candidates to fill this role due to their high specificity, sensitivity, rapid detection, and simple preparation. However, this sensor class suffers from severe baseline drift in the complex matrix probably due to the nonspecific adsorption of components. Here, we introduce a series of self-assembled monolayers with a variety of hydrophobic functional groups into an E-AB sensor platform, achieving enhancement of the antifouling performance and thus the detection performance (e.g., stability, sensitivity, and specificity). We reveal that the antifouling performance enhanced by such hydrophobic SAMs is probably due to its instant adsorption of components onto the surface, rather than the repelling of these components by hydrophilic SAMs in previous reports.
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Affiliation(s)
- Zishuo Zhang
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Yuanyuan Wang
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Ziyin Mei
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Yiming Wang
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Hui Li
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Shaoguang Li
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Fan Xia
- State Key Laboratory of Biogeology and Environmental Geology, Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
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30
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Radwan O, Brothers MC, Coyle V, Chapleau ME, Chapleau RR, Kim SS, Ruiz ON. Electrochemical biosensor for rapid detection of fungal contamination in fuel systems. Biosens Bioelectron 2022; 211:114374. [DOI: 10.1016/j.bios.2022.114374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/11/2022] [Accepted: 05/12/2022] [Indexed: 11/26/2022]
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31
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Pellitero MA, Arroyo-Currás N. Study of surface modification strategies to create glassy carbon-supported, aptamer-based sensors for continuous molecular monitoring. Anal Bioanal Chem 2022; 414:5627-5641. [PMID: 35352164 PMCID: PMC9242903 DOI: 10.1007/s00216-022-04015-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 02/18/2022] [Accepted: 03/08/2022] [Indexed: 11/28/2022]
Abstract
Electrochemical, aptamer-based (E-AB) sensors uniquely enable reagentless, reversible, and continuous molecular monitoring in biological fluids. Because of this ability, E-AB sensors have been proposed for therapeutic drug monitoring. However, to achieve translation from the bench to the clinic, E-AB sensors should ideally operate reliably and continuously for periods of days. Instead, because these sensors are typically fabricated on gold surfaces via self-assembly of alkanethiols that are prone to desorption from electrode surfaces, they undergo significant signal losses in just hours. To overcome this problem, our group is attempting to migrate E-AB sensor interfaces away from thiol-on-gold assembly towards stronger covalent bonds. Here, we explore the modification of carbon electrodes as an alternative substrate for E-AB sensors. We investigated three strategies to functionalize carbon surfaces: (I) anodization to generate surface carboxylic groups, (II) electrografting of arenediazonium ions, and (III) electrografting of primary aliphatic amines. Our results indicate that electrografting of primary aliphatic amines is the only strategy achieving monolayer organization and packing densities closely comparable to those obtained by alkanethiols on gold. In addition, the resulting monolayers enable covalent tethering of DNA aptamers and support electrochemical sensing of small molecule targets or complimentary DNA strands. These monolayers also achieve superior stability under continuous voltammetric interrogation in biological fluids relative to benchmark thiol-on-gold monolayers when a positive voltage scan window is used. Based on these results, we postulate the electrografting of primary aliphatic amines as a path forward to develop carbon-supported E-AB sensors with increased operational stability.
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Affiliation(s)
- Miguel Aller Pellitero
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Hunterian Building, Room 314, 725 North Wolfe St., Baltimore, MD, 21205, USA.
| | - Netzahualcóyotl Arroyo-Currás
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Hunterian Building, Room 314, 725 North Wolfe St., Baltimore, MD, 21205, USA.
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA.
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32
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Wu Y, Tehrani F, Teymourian H, Mack J, Shaver A, Reynoso M, Kavner J, Huang N, Furmidge A, Duvvuri A, Nie Y, Laffel L, Doyle FJ, Patti ME, Dassau E, Wang J, Arroyo-Currás N. Microneedle Aptamer-Based Sensors for Continuous, Real-Time Therapeutic Drug Monitoring. Anal Chem 2022; 94:8335-8345. [PMID: 35653647 PMCID: PMC9202557 DOI: 10.1021/acs.analchem.2c00829] [Citation(s) in RCA: 56] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 05/19/2022] [Indexed: 12/21/2022]
Abstract
The ability to continuously monitor the concentration of specific molecules in the body is a long-sought goal of biomedical research. For this purpose, interstitial fluid (ISF) was proposed as the ideal target biofluid because its composition can rapidly equilibrate with that of systemic blood, allowing the assessment of molecular concentrations that reflect full-body physiology. In the past, continuous monitoring in ISF was enabled by microneedle sensor arrays. Yet, benchmark microneedle sensors can only detect molecules that undergo redox reactions, which limits the ability to sense metabolites, biomarkers, and therapeutics that are not redox-active. To overcome this barrier, here, we expand the scope of these devices by demonstrating the first use of microneedle-supported electrochemical, aptamer-based (E-AB) sensors. This platform achieves molecular recognition based on affinity interactions, vastly expanding the scope of molecules that can be sensed. We report the fabrication of microneedle E-AB sensor arrays and a method to regenerate them for multiple uses. In addition, we demonstrate continuous molecular measurements using these sensors in flow systems in vitro using single and multiplexed microneedle array configurations. Translation of the platform to in vivo measurements is possible as we demonstrate with a first E-AB measurement in the ISF of a rodent. The encouraging results reported in this work should serve as the basis for future translation of microneedle E-AB sensor arrays to biomedical research in preclinical animal models.
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Affiliation(s)
- Yao Wu
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21202, United States
| | - Farshad Tehrani
- Department
of Nanoengineering, University of California
San Diego, La Jolla, California 92093, United States
| | - Hazhir Teymourian
- Department
of Nanoengineering, University of California
San Diego, La Jolla, California 92093, United States
| | - John Mack
- Biochemistry,
Cellular and Molecular Biology, Johns Hopkins
University School of Medicine, Baltimore, Maryland 21202, United States
| | - Alexander Shaver
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21202, United States
| | - Maria Reynoso
- Department
of Nanoengineering, University of California
San Diego, La Jolla, California 92093, United States
| | - Jonathan Kavner
- Department
of Nanoengineering, University of California
San Diego, La Jolla, California 92093, United States
| | - Nickey Huang
- Department
of Nanoengineering, University of California
San Diego, La Jolla, California 92093, United States
| | - Allison Furmidge
- Department
of Nanoengineering, University of California
San Diego, La Jolla, California 92093, United States
| | - Andrés Duvvuri
- Department
of Nanoengineering, University of California
San Diego, La Jolla, California 92093, United States
| | - Yuhang Nie
- Department
of Nanoengineering, University of California
San Diego, La Jolla, California 92093, United States
| | - Lori
M. Laffel
- Joslin
Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215, United States
| | - Francis J. Doyle
- Harvard
John A. Paulson School of Engineering and Applied Sciences, Harvard University, Allston, Massachusetts 02134, United States
| | - Mary-Elizabeth Patti
- Joslin
Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215, United States
| | - Eyal Dassau
- Harvard
John A. Paulson School of Engineering and Applied Sciences, Harvard University, Allston, Massachusetts 02134, United States
| | - Joseph Wang
- Department
of Nanoengineering, University of California
San Diego, La Jolla, California 92093, United States
| | - Netzahualcóyotl Arroyo-Currás
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21202, United States
- Biochemistry,
Cellular and Molecular Biology, Johns Hopkins
University School of Medicine, Baltimore, Maryland 21202, United States
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33
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Shaver A, Arroyo-Currás N. The challenge of long-term stability for nucleic acid-based electrochemical sensors. CURRENT OPINION IN ELECTROCHEMISTRY 2022; 32:100902. [PMID: 36092288 PMCID: PMC9455832 DOI: 10.1016/j.coelec.2021.100902] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Nucleic acid-based electrochemical sensors are a versatile technology enabling affinity-based detection of a great variety of molecular targets, regardless of inherent electrochemical activity or enzymatic reactivity. Additionally, their modular interface and ease of fabrication enable rapid prototyping and sensor development. However, the technology has inhibiting limitations in terms of long-term stability that have precluded translation into clinically valuable platforms like continuous molecular monitors. In this opinion, we discuss published methods to address various aspects of sensor stability, including thiol-based monolayers and anti-biofouling capabilities. We hope the highlighted works will motivate the field to develop innovative strategies for extending the long-term operational life of nucleic acid-based electrochemical sensors.
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Affiliation(s)
- Alexander Shaver
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Netzahualcóyotl Arroyo-Currás
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, 21218, USA
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34
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Chen G, Chen W, Xu L, Jin H, Sun W, Lan J, Wu F, Zhang X, Zhang J, Chen J. Sensitive, Highly Stable, and Anti-Fouling Electrode with Hexanethiol and Poly-A Modification for Exosomal microRNA Detection. Anal Chem 2022; 94:5382-5391. [PMID: 35323012 DOI: 10.1021/acs.analchem.2c00069] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It remains a huge challenge to integrate the sensitivity, stability, reproducibility, and anti-fouling ability of electrochemical biosensors for practical applications. Herein, we propose a self-assembled electrode combining hexanethiol (HT), poly-adenine (poly-A), and cholesteryl-modified DNA to meet this challenge. HT can tightly pack at the electrode interface to form a hydrophobic self-assembled monolayer (SAM), effectively improving the stability and signal-to-noise ratio (SNR) of electrochemical detection. Cholesteryl-modified DNA was immobilized at the electrode through the hydrophobic interaction with HT to avoid the competition between the SAM and the DNA probe on the gold site. Thus, the assembly efficiency and uniformity of the DNA probe as well as the detection reproducibility were increased remarkedly. Poly-A was added on the HT assembled electrode to occupy the unreacted sites of gold to further enhance the anti-fouling ability. The combination of HT and poly-A allows the electrode to ensure favorable anti-fouling ability without sacrificing the detection performance. On this basis, we proposed a dual-signal amplification electrochemical biosensor for the detection of exosomal microRNAs, which showed excellent sensitivity with a detection limit down to 1.46 aM. Importantly, this method has been successfully applied to detect exosomal microRNA-21 in cells and human serum samples, proving its potential utility in cancer diagnosis.
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Affiliation(s)
- Guanyu Chen
- Department of Pharmaceutical Analysis, The School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, P.R. China.,Fujian Key Laboratory of Drug Target Discovery and Structural and Functional Research, The School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, P.R. China
| | - Wenqian Chen
- Department of Pharmaceutical Analysis, The School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, P.R. China.,Fujian Key Laboratory of Drug Target Discovery and Structural and Functional Research, The School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, P.R. China
| | - Lilan Xu
- Department of Pharmaceutical Analysis, The School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, P.R. China.,Fujian Key Laboratory of Drug Target Discovery and Structural and Functional Research, The School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, P.R. China
| | - Huixuan Jin
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian Province, P.R. China
| | - Weiming Sun
- Department of Pharmaceutical Analysis, The School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, P.R. China.,Fujian Key Laboratory of Drug Target Discovery and Structural and Functional Research, The School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, P.R. China
| | - Jianming Lan
- Department of Pharmaceutical Analysis, The School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, P.R. China.,Fujian Key Laboratory of Drug Target Discovery and Structural and Functional Research, The School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, P.R. China
| | - Fang Wu
- Department of Pharmaceutical Analysis, The School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, P.R. China.,Fujian Key Laboratory of Drug Target Discovery and Structural and Functional Research, The School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, P.R. China
| | - Xi Zhang
- Department of Clinical Pharmacy, The School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, P. R. China
| | - Jing Zhang
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian Province, P.R. China
| | - Jinghua Chen
- Department of Pharmaceutical Analysis, The School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, P.R. China.,Fujian Key Laboratory of Drug Target Discovery and Structural and Functional Research, The School of Pharmacy, Fujian Medical University, Fuzhou 350122, Fujian Province, P.R. China
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35
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Belmonte I, White RJ. 3-D printed microfluidics for rapid prototyping and testing of electrochemical, aptamer-based sensor devices under flow conditions. Anal Chim Acta 2022; 1192:339377. [PMID: 35057946 PMCID: PMC8931854 DOI: 10.1016/j.aca.2021.339377] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 11/04/2021] [Accepted: 12/13/2021] [Indexed: 02/03/2023]
Abstract
We demonstrate the ability to rapidly prototype and fabricate an epoxy-embedded electrode platform and microfluidic device suitable for using electrochemical biosensors under flow conditions. We utilize three-dimensional (3-D) printing to rapidly prototype molds to fabricate epoxy-embedded electrodes in addition to molds for rapid prototyping of PDMS microfluidic components. We characterize the bare gold epoxy-embedded electrodes using ferricyanide as a redox indicator and then characterize the performance of an adenosine triphosphate (ATP) specific electrochemical, aptamer-based (E-AB) sensor. We then incorporate the ATP specific E-AB sensors into the microfluidic device to study and take advantage of the dynamic response this class of sensor offers. We were able to flow varying concentrations of target analyte and monitor the dynamic response of the sensors to the changing concentration. This work demonstrates the ability to rapidly prototype E-AB sensors under flow conditions using 3-D printing which can lead to rapid and affordable point-of-care or fieldable applications where dynamic measurements of concentration, specificity and sensitivity and multiplex detection are necessary.
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Affiliation(s)
- Israel Belmonte
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, United States
| | - Ryan J. White
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, United States,Department of Electrical Engineering and Computer Science, University of Cincinnati, Cincinnati, Ohio 45221-0172, United States
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36
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Chen ZM, Mou Q, Wu SH, Xie Y, Salminen K, Sun JJ. Real-Time Tunable Dynamic Range for Calibration-Free Biomolecular Measurements with a Temperature-Modulated Electrochemical Aptamer-Based Sensor in an Unprocessed Actual Sample. Anal Chem 2021; 94:1397-1405. [PMID: 34962777 DOI: 10.1021/acs.analchem.1c04697] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The sensing technologies for monitoring molecular analytes in biological fluids with high frequency and in real time could enable a broad range of applications in personalized healthcare and clinical diagnosis. However, due to the limited dynamic range (less than 81-fold), real-time analysis of biomolecular concentration varying over multiple orders of magnitude is a severe challenge faced by this class of analytical platforms. For the first time, we describe here that temperature-modulated electrochemical aptamer-based sensors with a dynamically adjustable calibration-free detection window could enable continuous, real-time, and accurate response for the several-hundredfold target concentration changes in unprocessed actual samples. Specifically, we could regulate the electrode surface temperature of sensors to obtain the corresponding dynamic range because of the temperature-dependent affinity variations. This temperature modulation method relies on an alternate hot and cold electrode reported by our group, whose surface could actively be heated and cooled without the need for altering ambient temperature, thus likewise applying for the flowing system. We then performed dual-frequency calibration-free measurements at different interface temperatures, thus achieving an extended detection window from 25 to 2500 μM for procaine in undiluted urine, 1-500 μM for adenosine triphosphate, and 5-2000 μM for adenosine in undiluted serum. The resulting sensor architecture could drastically expand the real-time response range accessible to these continuous, reagent-less biosensors.
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Affiliation(s)
- Zhi-Min Chen
- Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou 350108, Fujian, China
| | - Qi Mou
- Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou 350108, Fujian, China
| | - Sheng-Hong Wu
- Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou 350108, Fujian, China
| | - Yu Xie
- Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou 350108, Fujian, China
| | - Kalle Salminen
- Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou 350108, Fujian, China
| | - Jian-Jun Sun
- Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou 350108, Fujian, China
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37
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Wehmeyer KR, White RJ, Kissinger PT, Heineman WR. Electrochemical Affinity Assays/Sensors: Brief History and Current Status. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2021; 14:109-131. [PMID: 34314225 DOI: 10.1146/annurev-anchem-061417-125655] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The advent of electrochemical affinity assays and sensors evolved from pioneering efforts in the 1970s to broaden the field of analytes accessible to the selective and sensitive performance of electrochemical detection. The foundation of electrochemical affinity assays/sensors is the specific capture of an analyte by an affinity element and the subsequent transduction of this event into a measurable signal. This review briefly covers the early development of affinity assays and then focuses on advances in the past decade. During this time, progress on electroactive labels, including the use of nanoparticles, quantum dots, organic and organometallic redox compounds, and enzymes with amplification schemes, has led to significant improvements in sensitivity. The emergence of nanomaterials along with microfabrication and microfluidics technology enabled research pathways that couple the ease of use of electrochemical detection for the development of devices that are more user friendly, disposable, and employable, such as lab-on-a-chip, paper, and wearable sensors.
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Affiliation(s)
- Kenneth R Wehmeyer
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, USA; , ,
| | - Ryan J White
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, USA; , ,
- Department of Electrical Engineering and Computer Science, University of Cincinnati, Cincinnati, Ohio 45221-0030, USA
| | - Peter T Kissinger
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA;
| | - William R Heineman
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, USA; , ,
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38
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Animesh S, Singh YD. A Comprehensive Study on Aptasensors For Cancer Diagnosis. Curr Pharm Biotechnol 2021; 22:1069-1084. [PMID: 32957883 DOI: 10.2174/1389201021999200918152721] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/23/2020] [Accepted: 08/18/2020] [Indexed: 12/24/2022]
Abstract
Cancer is the most devastating disease in the present scenario, killing millions of people every year. Early detection, accurate diagnosis, and timely treatment are considered to be the most effective ways to control this disease. Rapid and efficient detection of cancer at their earliest stage is one of the most significant challenges in cancer detection and cure. Numerous diagnostic modules have been developed to detect cancer cells early. As nucleic acid equivalent to antibodies, aptamers emerge as a new class of molecular probes that can identify cancer-related biomarkers or circulating rare cancer/ tumor cells with very high specificity and sensitivity. The amalgamation of aptamers with the biosensing platforms gave birth to "Aptasensors." The advent of highly sensitive aptasensors has opened up many new promising point-of-care diagnostics for cancer. This comprehensive review focuses on the newly developed aptasensors for cancer diagnostics.
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Affiliation(s)
- Sambhavi Animesh
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, India
| | - Yengkhom D Singh
- Department of Post-Harvest Technology, College of Horticulture and Forestry, Central Agricultural University, Pasighat, Arunachal Pradesh, 791102, India
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39
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Shaver A, Kundu N, Young BE, Vieira PA, Sczepanski JT, Arroyo-Currás N. Nuclease Hydrolysis Does Not Drive the Rapid Signaling Decay of DNA Aptamer-Based Electrochemical Sensors in Biological Fluids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:5213-5221. [PMID: 33876937 PMCID: PMC8176561 DOI: 10.1021/acs.langmuir.1c00166] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Electrochemical aptamer-based (E-AB) sensors are a technology capable of real-time monitoring of drug concentrations directly in the body. These sensors achieve their selectivity from surface-attached aptamers, which alter their conformation upon target binding, thereby causing a change in electron transfer kinetics between aptamer-bound redox reporters and the electrode surface. Because, in theory, aptamers can be selected for nearly any target of interest, E-AB sensors have far-reaching potential for diagnostic and biomedical applications. However, a remaining critical weakness in the platform lies in the time-dependent, spontaneous degradation of the bioelectronic interface. This progressive degradation-seen in part as a continuous drop in faradaic current from aptamer-attached redox reporters-limits the in vivo operational life of E-AB sensors to less than 12 h, prohibiting their long-term application for continuous molecular monitoring in humans. In this work, we study the effects of nuclease action on the signaling lifetime of E-AB sensors, to determine whether the progressive signal loss is caused by hydrolysis of DNA aptamers and thus the loss of signaling moieties from the sensor surface. We continuously interrogate sensors deployed in several undiluted biological fluids at 37 °C and inject nuclease to reach physiologically relevant concentrations. By employing both naturally occurring d-DNA and the nuclease-resistant enantiomer l-DNA, we determine that within the current lifespan of state-of-the-art E-AB sensors, nuclease hydrolysis is not the dominant cause of sensor signal loss under the conditions we tested. Instead, signal loss is driven primarily by the loss of monolayer elements-both blocking alkanethiol and aptamer monolayers-from the electrode surface. While use of l-DNA aptamers may extend the E-AB operational life in the long term, the critical issue of passive monolayer loss must be addressed before those effects can be seen.
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Affiliation(s)
- Alexander Shaver
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21202, United States
| | - Nandini Kundu
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Brian E Young
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Philip A Vieira
- Department of Psychology, California State University Dominguez Hills, Carson, California 90747, United States
| | - Jonathan T Sczepanski
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Netzahualcóyotl Arroyo-Currás
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21202, United States
- Department of Chemical and Biomolecular Engineering and Institute for NanoBioTechnology, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
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40
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Reagentless biomolecular analysis using a molecular pendulum. Nat Chem 2021; 13:428-434. [PMID: 33686229 DOI: 10.1038/s41557-021-00644-y] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 01/22/2021] [Indexed: 01/31/2023]
Abstract
The development of reagentless sensors that can detect molecular analytes in biological fluids could enable a broad range of applications in personalized health monitoring. However, only a limited set of molecular inputs can currently be detected using reagentless sensors. Here, we report a sensing mechanism that is compatible with the analysis of proteins that are important physiological markers of stress, allergy, cardiovascular health, inflammation and cancer. The sensing method is based on the motion of an inverted molecular pendulum that exhibits field-induced transport modulated by the presence of a bound analyte. We measure the sensor's electric field-mediated transport using the electron-transfer kinetics of an attached reporter molecule. Using time-resolved electrochemical measurements that enable unidirectional motion of our sensor, the presence of an analyte bound to our sensor complex can be tracked continuously in real time. We show that this sensing approach is compatible with making measurements in blood, saliva, urine, tears and sweat and that the sensors can collect data in situ in living animals.
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41
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Li S, Wang Y, Zhang Z, Wang Y, Li H, Xia F. Exploring End-Group Effect of Alkanethiol Self-Assembled Monolayers on Electrochemical Aptamer-Based Sensors in Biological Fluids. Anal Chem 2021; 93:5849-5855. [PMID: 33787229 DOI: 10.1021/acs.analchem.1c00085] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The continuous, real-time monitoring of specific analytes in situ in biological fluids would provide personalized, high-precision pharmacokinetic information for the goal of precision medicine. Due to their conformationally linked signaling mechanism, electrochemical aptamer-based (E-AB) sensors are promising candidates for accurate measurements in such complex media. They suffer, however, from severe baseline drift when interrogated continuously and in real-time manner. In response, here, we investigate a couple of self-assembled monolayers in the application of E-AB sensors, achieving the improvement of their baseline stability and simultaneous modulation of sensor performance, e.g., target affinity and specificity.
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Affiliation(s)
- Shaoguang Li
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Yuanyuan Wang
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Zishuo Zhang
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Yiming Wang
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Hui Li
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Fan Xia
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
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42
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Pellitero MA, Curtis SD, Arroyo-Currás N. Interrogation of Electrochemical Aptamer-Based Sensors via Peak-to-Peak Separation in Cyclic Voltammetry Improves the Temporal Stability and Batch-to-Batch Variability in Biological Fluids. ACS Sens 2021; 6:1199-1207. [PMID: 33599479 DOI: 10.1021/acssensors.0c02455] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Electrochemical, aptamer-based (E-AB) sensors support continuous, real-time measurements of specific molecular targets in complex fluids such as undiluted serum. They achieve these measurements by using redox-reporter-modified, electrode-attached aptamers that undergo target binding-induced conformational changes which, in turn, change electron transfer between the reporter and the sensor surface. Traditionally, E-AB sensors are interrogated via pulse voltammetry to monitor binding-induced changes in transfer kinetics. While these pulse techniques are sensitive to changes in electron transfer, they also respond to progressive changes in the sensor surface driven by biofouling or monolayer desorption and, consequently, present a significant drift. Moreover, we have empirically observed that differential voltage pulsing can accelerate monolayer desorption from the sensor surface, presumably via field-induced actuation of aptamers. Here, in contrast, we demonstrate the potential advantages of employing cyclic voltammetry to measure electron-transfer changes directly. In our approach, the target concentration is reported via changes in the peak-to-peak separation, ΔEP, of cyclic voltammograms. Because the magnitude of ΔEP is insensitive to variations in the number of aptamer probes on the electrode, ΔEP-interrogated E-AB sensors are resistant to drift and show decreased batch-to-batch and day-to-day variability in sensor performance. Moreover, ΔEP-based measurements can also be performed in a few hundred milliseconds and are, thus, competitive with other subsecond interrogation strategies such as chronoamperometry but with the added benefit of retaining sensor capacitance information that can report on monolayer stability over time.
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Affiliation(s)
- Miguel Aller Pellitero
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21202, United States
| | - Samuel D. Curtis
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21202, United States
| | - Netzahualcóyotl Arroyo-Currás
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21202, United States
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland 21218, United States
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43
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Weaver SD, Whelan RJ. Characterization of DNA aptamer-protein binding using fluorescence anisotropy assays in low-volume, high-efficiency plates. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2021; 13:1302-1307. [PMID: 33533761 DOI: 10.1039/d0ay02256j] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Aptamers have many useful attributes including specific binding to molecular targets. After aptamers are identified, their target binding must be characterized. Fluorescence anisotropy (FA) is one technique that can be used to characterize affinity and to optimize aptamer-target interactions. Efforts to make FA assays more efficient by reducing assay volume and time from mixing to measurement may save time and resources by minimizing consumption of costly reagents. Here, we use thrombin and two thrombin-binding aptamers as a model system to show that plate-based FA experiments can be performed in volumes as low as 2 μL per well with 20 minute incubations with minimal loss in assay precision. We demonstrate that the aptamer-thrombin interaction is best modelled with the Hill equation, indicating cooperative binding. The miniaturization of this assay has implications in drug development, as well as in the efficiency of aptamer selection workflows by allowing for higher throughput aptamer analysis.
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Affiliation(s)
- Simon D Weaver
- Integrated Biomedical Sciences Graduate Program, University of Notre Dame, Notre Dame, IN, USA
| | - Rebecca J Whelan
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA.
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44
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Abstract
Current knowledge of the disposition kinetics of endogenous metabolites is founded almost entirely on poorly time-resolved experiments in which samples are removed from the body for later, benchtop analysis. Here, in contrast, we describe real-time, seconds-resolved measurements of plasma phenylalanine collected in situ in the body via electrochemical aptamer-based (EAB) sensors, a platform technology that is independent of the reactivity of its targets and thus is generalizable to many. Specifically, using indwelling EAB sensors, we have monitored plasma phenylalanine in live rats with a few micromolar precision and a 12 s temporal resolution, identifying a large-amplitude, few-seconds phase in the animals' metabolic response that had not previously been reported. Using the hundreds of individual measurements that the approach provides from each animal, we also identify inter-subject variability, including statistically significant differences associated with the feeding status. These results highlight the power of in vivo EAB measurements, an advancement that could dramatically impact our understanding of physiology and provide a valuable new tool for the monitoring and treatment of metabolic disorders.
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45
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Downs AM, Gerson J, Ploense KL, Plaxco KW, Dauphin-Ducharme P. Subsecond-Resolved Molecular Measurements Using Electrochemical Phase Interrogation of Aptamer-Based Sensors. Anal Chem 2020; 92:14063-14068. [PMID: 32959647 DOI: 10.1021/acs.analchem.0c03109] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Recent years have seen the development of a number of biosensor architectures that rely on target binding-induced changes in the rate of electron transfer from an electrode-bound receptor. Most often, the interrogation of these sensors has relied on voltammetric methods, such as square-wave voltammetry, which limit their time resolution to a few seconds. Here, we describe the use of an impedance-based approach, which we have termed electrochemical phase interrogation, as a means of collecting high time resolution measurements with sensors in this class. Specifically, using changes in the electrochemical phase to monitor target binding in an electrochemical-aptamer based (EAB) sensor, we achieve subsecond temporal resolution and multihour stability in measurements performed directly in undiluted whole blood. Electrochemical phase interrogation also offers improved insights into EAB sensors' signaling mechanism. By modeling the interfacial resistance and capacitance using equivalent circuits, we find that the only parameter that is altered by target binding is the charge-transfer resistance. This confirms previous claims that binding-induced changes in electron-transfer kinetics drive signaling in this class of sensors. Considering that a wide range of electrochemical biosensor architectures rely on this signaling mechanism, we believe that electrochemical phase interrogation may prove generalizable toward subsecond measurements of molecular targets.
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Affiliation(s)
- Alex M Downs
- Department of Mechanical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States.,Center for Bioengineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Julian Gerson
- Department of Psychological and Brain Sciences, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Kyle L Ploense
- Institute for Behavioral Genetics, University of Colorado, Boulder, Colorado 80309, United States
| | - Kevin W Plaxco
- Department of Mechanical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States.,Center for Bioengineering, University of California Santa Barbara, Santa Barbara, California 93106, United States.,Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
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46
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Parolo C, Idili A, Ortega G, Csordas A, Hsu A, Arroyo-Currás N, Yang Q, Ferguson BS, Wang J, Plaxco KW. Real-Time Monitoring of a Protein Biomarker. ACS Sens 2020; 5:1877-1881. [PMID: 32619092 DOI: 10.1021/acssensors.0c01085] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The ability to monitor protein biomarkers continuously and in real-time would significantly advance the precision of medicine. Current protein-detection techniques, however, including ELISA and lateral flow assays, provide only time-delayed, single-time-point measurements, limiting their ability to guide prompt responses to rapidly evolving, life-threatening conditions. In response, here we present an electrochemical aptamer-based sensor (EAB) that supports high-frequency, real-time biomarker measurements. Specifically, we have developed an electrochemical, aptamer-based (EAB) sensor against Neutrophil Gelatinase-Associated Lipocalin (NGAL), a protein that, if present in urine at levels above a threshold value, is indicative of acute renal/kidney injury (AKI). When deployed inside a urinary catheter, the resulting reagentless, wash-free sensor supports real-time, high-frequency monitoring of clinically relevant NGAL concentrations over the course of hours. By providing an "early warning system", the ability to measure levels of diagnostically relevant proteins such as NGAL in real-time could fundamentally change how we detect, monitor, and treat many important diseases.
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Affiliation(s)
- Claudio Parolo
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Andrea Idili
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Gabriel Ortega
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Andrew Csordas
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Alex Hsu
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Netzahualcóyotl Arroyo-Currás
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, United States
| | - Qin Yang
- Aptitude Medical Systems, Inc., Santa Barbara, California 93105, United States
| | | | - Jinpeng Wang
- Aptitude Medical Systems, Inc., Santa Barbara, California 93105, United States
| | - Kevin W. Plaxco
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, United States
- Interdepartmental Program in Biomolecular Science and Engineering University of California, Santa Barbara, Santa Barbara, California 93106, United States
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