1
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Yang Y, Gao X, Widdicombe B, Zhang X, Zielinski JL, Cheng T, Gunatilaka A, Leung KK, Plaxco KW, Rajasekharan Unnithan R, Stewart AG. Dual-Purpose Aptamer-Based Sensors for Real-Time, Multiplexable Monitoring of Metabolites in Cell Culture Media. ACS NANO 2024. [PMID: 39255458 DOI: 10.1021/acsnano.4c06813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2024]
Abstract
The availability of high-frequency, real-time measurements of the concentrations of specific metabolites in cell culture systems will enable a deeper understanding of cellular metabolism and facilitate the application of good laboratory practice standards in cell culture protocols. However, currently available approaches to this end either are constrained to single-time-point and single-parameter measurements or are limited in the range of detectable analytes. Electrochemical aptamer-based (EAB) biosensors have demonstrated utility in real-time monitoring of analytes in vivo in blood and tissues. Here, we characterize a pH-sensing capability of EAB sensors that is independent of the specific target analyte of the aptamer sequence. We applied this dual-purpose EAB to the continuous measurement of pH and phenylalanine in several in vitro cell culture settings. The miniature EAB sensor that we developed exhibits rapid response times, good stability, high repeatability, and biologically relevant sensitivity. We also developed and characterized a leak-free reference electrode that mitigates the potential cytotoxic effects of silver ions released from conventional reference electrodes. Using the resulting dual-purpose sensor, we performed hourly measurements of pH and phenylalanine concentrations in the medium superfusing cultured epithelial tumor cell lines (A549, MDA-MB-23) and a human fibroblast cell line (MRC-5) for periods of up to 72 h. Our scalable technology may be multiplexed for high-throughput monitoring of pH and multiple analytes in support of the broad metabolic qualification of microphysiological systems.
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Affiliation(s)
- Yiling Yang
- Department of Electrical and Electronic Engineering, University of Melbourne, Melbourne, Victoria 3010, Australia
- ARC Centre for Personalised Therapeutics Technologies, Melbourne, Victoria 3010, Australia
| | - Xumei Gao
- Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, Victoria 3010, Australia
- ARC Centre for Personalised Therapeutics Technologies, Melbourne, Victoria 3010, Australia
| | - Bryce Widdicombe
- Department of Electrical and Electronic Engineering, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Xiaodan Zhang
- Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Jana Lorraine Zielinski
- Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Tianhong Cheng
- Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Avanka Gunatilaka
- Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Kaylyn K Leung
- Department of Chemistry and Biochemistry, 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
| | - Ranjith Rajasekharan Unnithan
- Department of Electrical and Electronic Engineering, University of Melbourne, Melbourne, Victoria 3010, Australia
- ARC Centre for Personalised Therapeutics Technologies, Melbourne, Victoria 3010, Australia
| | - Alastair G Stewart
- Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, Victoria 3010, Australia
- ARC Centre for Personalised Therapeutics Technologies, Melbourne, Victoria 3010, Australia
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2
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Probst D, Batchu K, Younce JR, Sode K. Levodopa: From Biological Significance to Continuous Monitoring. ACS Sens 2024; 9:3828-3839. [PMID: 39047295 PMCID: PMC11348912 DOI: 10.1021/acssensors.4c00602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 06/21/2024] [Accepted: 07/03/2024] [Indexed: 07/27/2024]
Abstract
A continuous levodopa sensor can improve the quality of life for patients suffering with Parkinson's disease by enhancing levodopa titration and treatment effectiveness; however, its development is currently hindered by the absence of a specific levodopa molecular recognition element and limited insights into how real-time monitoring might affect clinical outcomes. This gap in research contributes to clinician uncertainty regarding the practical value of continuous levodopa monitoring data. This paper examines the current state of levodopa sensing and the inherent limitations in today's methods. Further, these challenges are described, including aspects such as interference from the metabolic pathway and adjunct medications, temporal resolution, and clinical questions, with a specific focus on a comprehensive selection of molecules, such as adjunct medications and structural isomers, as an interferent panel designed to assess and validate future levodopa sensors. We review insights and lessons from previously reported levodopa sensors and present a comparative analysis of potential molecular recognition elements, discussing their advantages and drawbacks.
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Affiliation(s)
- David Probst
- Joint
Department of Biomedical Engineering, The
University of North Carolina at Chapel Hill and North Carolina State
University, Chapel Hill, North Carolina 27599, United States
| | - Kartheek Batchu
- Joint
Department of Biomedical Engineering, The
University of North Carolina at Chapel Hill and North Carolina State
University, Chapel Hill, North Carolina 27599, United States
| | - John Robert Younce
- Department
of Neurology, University of North Carolina
at Chapel Hill, Chapel
Hill, North Carolina 27599, United States
| | - Koji Sode
- Joint
Department of Biomedical Engineering, The
University of North Carolina at Chapel Hill and North Carolina State
University, Chapel Hill, North Carolina 27599, United States
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3
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Verrinder E, Gerson J, Leung K, Kippin TE, Plaxco KW. Dual-Frequency, Ratiometric Approaches to EAB Sensor Interrogation Support the Calibration-Free Measurement of Specific Molecules In Vivo. ACS Sens 2024; 9:3205-3211. [PMID: 38775190 DOI: 10.1021/acssensors.4c00516] [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: 06/29/2024]
Abstract
Electrochemical aptamer-based (EAB) sensors represent the first molecular measurement technology that is both (1) independent of the chemical reactivity of the target, and thus generalizable to many targets and (2) able to function in an accurate, drift-corrected manner in situ in the living body. Signaling in EAB sensors is generated when an electrode-bound aptamer binds to its target ligand, altering the rate of electron transfer from an attached redox reporter and producing an easily detectable change in peak current when the sensor is interrogated using square wave voltammetry. Due to differences in the microscopic surface area of the interrogating electrodes, the baseline peak currents obtained from EAB sensors, however, can be highly variable. To overcome this, we have historically performed single-point calibration using measurements performed in a single sample of known target concentration. Here, however, we explore approaches to EAB sensor operation that negate the need to perform even single-point calibration of individual sensors. These are a ratiometric approach employing the ratio of the peak currents observed at two distinct square wave frequencies, and a kinetic differential measurement approach that employs the difference between peak currents seen at the two frequencies. Using in vivo measurements of vancomycin and phenylalanine as our test bed, we compared the output of these methods with that of the same sensor when single-point calibration was employed. Doing so we find that both methods support accurately drift-corrected measurements in vivo in live rats, even when employing rather crudely handmade devices. By removing the need to calibrate each individual sensor in a sample of known target concentration, these interrogation methods should significantly simplify the use of EAB sensors for in vivo applications.
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Affiliation(s)
- Elsi Verrinder
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Julian Gerson
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, United States
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Kaylyn Leung
- 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
| | - 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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4
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Gerson J, Erdal MK, Dauphin-Ducharme P, Idili A, Hespanha JP, Plaxco KW, Kippin TE. A high-precision view of intercompartmental drug transport via simultaneous, seconds-resolved, in situ measurements in the vein and brain. Br J Pharmacol 2024. [PMID: 38877797 DOI: 10.1111/bph.16471] [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: 07/21/2023] [Revised: 04/06/2024] [Accepted: 04/19/2024] [Indexed: 06/16/2024] Open
Abstract
BACKGROUND AND PURPOSE The ability to measure specific molecules at multiple sites within the body simultaneously, and with a time resolution of seconds, could greatly advance our understanding of drug transport and elimination. EXPERIMENTAL APPROACH As a proof-of-principle demonstration, here we describe the use of electrochemical aptamer-based (EAB) sensors to measure transport of the antibiotic vancomycin from the plasma (measured in the jugular vein) to the cerebrospinal fluid (measured in the lateral ventricle) of live rats with temporal resolution of a few seconds. KEY RESULTS In our first efforts, we made measurements solely in the ventricle. Doing so we find that, although the collection of hundreds of concentration values over a single drug lifetime enables high-precision estimates of the parameters describing intracranial transport, due to a mathematical equivalence, the data produce two divergent descriptions of the drug's plasma pharmacokinetics that fit the in-brain observations equally well. The simultaneous collection of intravenous measurements, however, resolves this ambiguity, enabling high-precision (typically of ±5 to ±20% at 95% confidence levels) estimates of the key pharmacokinetic parameters describing transport from the blood to the cerebrospinal fluid in individual animals. CONCLUSIONS AND IMPLICATIONS The availability of simultaneous, high-density 'in-vein' (plasma) and 'in-brain' (cerebrospinal fluid) measurements provides unique opportunities to explore the assumptions almost universally employed in earlier compartmental models of drug transport, allowing the quantitative assessment of, for example, the pharmacokinetic effects of physiological processes such as the bulk transport of the drug out of the CNS via the dural venous sinuses.
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Affiliation(s)
- Julian Gerson
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, California, USA
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, California, USA
| | - Murat Kaan Erdal
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, California, USA
| | - Philippe Dauphin-Ducharme
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California, USA
| | - Andrea Idili
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California, USA
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, Rome, Italy
| | - Joao P Hespanha
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, California, USA
| | - Kevin W Plaxco
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California, USA
- Center for Bioengineering, University of California, Santa Barbara, Santa Barbara, California, USA
- Interdepartmental Program in Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, California, USA
| | - Tod E Kippin
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, California, USA
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, California, USA
- Interdepartmental Program in Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, California, USA
- Department of Molecular Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, California, USA
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5
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Fiore L, Mazzaracchio V, Gosti C, Duranti L, Vitiello R, Maccauro G, Arduini F. Functionalized orthopaedic implant as pH electrochemical sensing tool for smart diagnosis of hardware infection. Analyst 2024; 149:3085-3096. [PMID: 38712737 DOI: 10.1039/d4an00253a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
In the orthopaedic surgery field, the use of medical implants to treat a patient's bone fracture is nowadays a common practice, nevertheless, it is associated with possible cases of infection. The consequent hardware infection can lead to implant failure and systemic infections, with prolonged hospitalization, time-consuming rehabilitation treatments, and extended antibiotic therapy. Hardware infections are strictly related to bacterial adhesion to the implant, leading to infection occurrence and consequent pH decreasing from physiological level to acid pH. Here, we demonstrate the new strategy to use an orthopaedic implant functionalized with iridium oxide film as the working electrode for the potentiometric monitoring of pH in hardware infection diagnosis. A functional investigation was focused on selecting the implant material, namely titanium, titanium alloy, and stainless steel, and the component, namely screws and implants. After selecting the titanium-based implant as the working electrode and a silver wire as the reference electrode in the final configuration of the smart sensing orthopaedic implant, a calibration curve was performed in standard solutions. An equation equal to y = (0.76 ± 0.02) - (0.068 ± 0.002) x, R2 = 0.996, was obtained in the pH range of 4-8. Subsequently, hysteresis, interference, matrix effect, recovery study, and storage stability were investigated to test the overall performance of the sensing device, demonstrating the tremendous potential of electrochemical sensors to deliver the next generation of smart orthopaedic implants.
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Affiliation(s)
- Luca Fiore
- Department of Chemical Science and Technologies, University of Rome "Tor Vergata", via della Ricerca Scientifica, 00133 Rome, Italy.
- SENSE4MED, Via Bitonto 139, 00133, Rome, Italy
| | - Vincenzo Mazzaracchio
- Department of Chemical Science and Technologies, University of Rome "Tor Vergata", via della Ricerca Scientifica, 00133 Rome, Italy.
| | - Christian Gosti
- Department of Chemical Science and Technologies, University of Rome "Tor Vergata", via della Ricerca Scientifica, 00133 Rome, Italy.
| | - Leonardo Duranti
- Department of Chemical Science and Technologies, University of Rome "Tor Vergata", via della Ricerca Scientifica, 00133 Rome, Italy.
| | - Raffaele Vitiello
- Università Cattolica del Sacro Cuore, Rome, Italy
- Fondazione Policlinico Universitario Agostino Gemelli Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
| | - Giulio Maccauro
- Università Cattolica del Sacro Cuore, Rome, Italy
- Fondazione Policlinico Universitario Agostino Gemelli Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
| | - Fabiana Arduini
- Department of Chemical Science and Technologies, University of Rome "Tor Vergata", via della Ricerca Scientifica, 00133 Rome, Italy.
- SENSE4MED, Via Bitonto 139, 00133, Rome, Italy
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6
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Leung KK, Gerson J, Emmons N, Heemstra JM, Kippin TE, Plaxco KW. The Use of Xenonucleic Acids Significantly Reduces the In Vivo Drift of Electrochemical Aptamer-Based Sensors. Angew Chem Int Ed Engl 2024; 63:e202316678. [PMID: 38500260 DOI: 10.1002/anie.202316678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 02/09/2024] [Accepted: 03/17/2024] [Indexed: 03/20/2024]
Abstract
Electrochemical aptamer-based sensors support the high-frequency, real-time monitoring of molecules-of-interest in vivo. Achieving this requires methods for correcting the sensor drift seen during in vivo placements. While this correction ensures EAB sensor measurements remain accurate, as drift progresses it reduces the signal-to-noise ratio and precision. Here, we show that enzymatic cleavage of the sensor's target-recognizing DNA aptamer is a major source of this signal loss. To demonstrate this, we deployed a tobramycin-detecting EAB sensor analog fabricated with the DNase-resistant "xenonucleic acid" 2'O-methyl-RNA in a live rat. In contrast to the sensor employing the equivalent DNA aptamer, the 2'O-methyl-RNA aptamer sensor lost very little signal and had improved signal-to-noise. We further characterized the EAB sensor drift using unstructured DNA or 2'O-methyl-RNA oligonucleotides. While the two devices drift similarly in vitro in whole blood, the in vivo drift of the 2'O-methyl-RNA-employing device is less compared to the DNA-employing device. Studies of the electron transfer kinetics suggested that the greater drift of the latter sensor arises due to enzymatic DNA degradation. These findings, coupled with advances in the selection of aptamers employing XNA, suggest a means of improving EAB sensor stability when they are used to perform molecular monitoring in the living body.
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Affiliation(s)
- Kaylyn K Leung
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, CA 93106, USA
- Center for Bioengineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Julian Gerson
- Department of Psychological and Brain Sciences, University of California, Santa Barbara
- Center for Bioengineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Nicole Emmons
- Department of Psychological and Brain Sciences, University of California, Santa Barbara
- Center for Bioengineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Jennifer M Heemstra
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Tod E Kippin
- Department of Psychological and Brain Sciences, University of California, Santa Barbara
- Department of Molecular Cellular and Developmental Biology, University of California, Santa Barbara
| | - Kevin W Plaxco
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, CA 93106, USA
- Center for Bioengineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA
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7
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Abeykoon SW, White RJ. Single Voltammetric Sweep Calibration-Free Interrogation of Electrochemical Aptamer-Based Sensors Employing Continuous Square Wave Voltammetry. Anal Chem 2024; 96:6958-6967. [PMID: 38662230 DOI: 10.1021/acs.analchem.3c05920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Continuous square wave voltammetry (cSWV) is a technique that enables the continuous collection of current data (at 100 kHz) to maximize the information content obtainable from a single voltammetric sweep. This data collection procedure results in the generation of multiple voltammograms corresponding to different effective square wave frequencies. The application of cSWV brings significant benefits to electrochemical aptamer-based (E-AB) sensors. The E-AB sensor platform permits continuous real-time monitoring of small biological molecules. Traditionally, E-AB sensors report only on changes in analyte concentration rather than absolute quantification in matrices when basal concentrations are not known a priori. This is because they exhibit a voltammetric peak current even in the absence of a target. However, using a dual-frequency approach, calibration-free sensing can be performed effectively, eliminating the sensor-to-sensor variation by taking ratiometric current responses obtained at two different frequencies from two different voltammetric sweeps. In employing our approach, cSWV provides a great advantage over the conventionally used square wave voltammetry since the required voltammograms are collected with a single sweep, which improves the temporal resolution of the measurement when considering the current at multiple frequencies for improved accuracy and reduced surface interrogation. Moreover, we show here that using cSWV provides significantly improved concentration predictions. E-AB sensors sensitive to ATP and tobramycin were interrogated across a wide range of concentrations. With this approach, cSWV allowed us to estimate the target concentration, retaining up to an ±5% error of the expected concentration when tested in buffer and complex media.
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Affiliation(s)
- Sanduni W Abeykoon
- 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
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8
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Alkhamis O, Canoura J, Wu Y, Emmons NA, Wang Y, Honeywell KM, Plaxco KW, Kippin TE, Xiao Y. High-Affinity Aptamers for In Vitro and In Vivo Cocaine Sensing. J Am Chem Soc 2024; 146:3230-3240. [PMID: 38277259 DOI: 10.1021/jacs.3c11350] [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: 01/28/2024]
Abstract
The ability to quantify cocaine in biological fluids is crucial for both the diagnosis of intoxication and overdose in the clinic as well as investigation of the drug's pharmacological and toxicological effects in the laboratory. To this end, we have performed high-stringency in vitro selection to generate DNA aptamers that bind cocaine with nanomolar affinity and clinically relevant specificity, thus representing a dramatic improvement over the current-generation, micromolar-affinity, low-specificity cocaine aptamers. Using these novel aptamers, we then developed two sensors for cocaine detection. The first, an in vitro fluorescent sensor, successfully detects cocaine at clinically relevant levels in 50% human serum without responding significantly to other drugs of abuse, endogenous substances, or a diverse range of therapeutic agents. The second, an electrochemical aptamer-based sensor, supports the real-time, seconds-resolved measurement of cocaine concentrations in vivo in the circulation of live animals. We believe the aptamers and sensors developed here could prove valuable for both point-of-care and on-site clinical cocaine detection as well as fundamental studies of cocaine neuropharmacology.
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Affiliation(s)
- Obtin Alkhamis
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27607, United States
| | - Juan Canoura
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27607, United States
| | - Yuyang Wu
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Nicole A Emmons
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, California 93106, United States
| | - Yuting Wang
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, California 93106, United States
| | - Kevin M Honeywell
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Kevin W Plaxco
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Tod E Kippin
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, California 93106, United States
| | - Yi Xiao
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27607, United States
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9
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Chamorro A, Rossetti M, Bagheri N, Porchetta A. Rationally Designed DNA-Based Scaffolds and Switching Probes for Protein Sensing. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2024; 187:71-106. [PMID: 38273204 DOI: 10.1007/10_2023_235] [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
The detection of a protein analyte and use of this type of information for disease diagnosis and physiological monitoring requires methods with high sensitivity and specificity that have to be also easy to use, rapid and, ideally, single step. In the last 10 years, a number of DNA-based sensing methods and sensors have been developed in order to achieve quantitative readout of protein biomarkers. Inspired by the speed, specificity, and versatility of naturally occurring chemosensors based on structure-switching biomolecules, significant efforts have been done to reproduce these mechanisms into the fabrication of artificial biosensors for protein detection. As an alternative, in scaffold DNA biosensors, different recognition elements (e.g., peptides, proteins, small molecules, and antibodies) can be conjugated to the DNA scaffold with high accuracy and precision in order to specifically interact with the target protein with high affinity and specificity. They have several advantages and potential, especially because the transduction signal can be drastically enhanced. Our aim here is to provide an overview of the best examples of structure switching-based and scaffold DNA sensors, as well as to introduce the reader to the rational design of innovative sensing mechanisms and strategies based on programmable functional DNA systems for protein detection.
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Affiliation(s)
| | - Marianna Rossetti
- Department of Chemistry, University of Rome Tor Vergata, Rome, Italy
| | - Neda Bagheri
- Department of Chemistry, University of Rome Tor Vergata, Rome, Italy
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10
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Hariri AA, Cartwright AP, Dory C, Gidi Y, Yee S, Thompson IAP, Fu KX, Yang K, Wu D, Maganzini N, Feagin T, Young BE, Afshar BH, Eisenstein M, Digonnet MJF, Vuckovic J, Soh HT. Modular Aptamer Switches for the Continuous Optical Detection of Small-Molecule Analytes in Complex Media. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2304410. [PMID: 37975267 DOI: 10.1002/adma.202304410] [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: 05/10/2023] [Revised: 11/10/2023] [Indexed: 11/19/2023]
Abstract
Aptamers are a promising class of affinity reagents because signal transduction mechanisms can be built into the reagent, so that they can directly produce a physically measurable output signal upon target binding. However, endowing the signal transduction functionality into an aptamer remains a trial-and-error process that can compromise its affinity or specificity and typically requires knowledge of the ligand binding domain or its structure. In this work, a design architecture that can convert an existing aptamer into a "reversible aptamer switch" whose kinetic and thermodynamic properties can be tuned without a priori knowledge of the ligand binding domain or its structure is described. Finally, by combining these aptamer switches with evanescent-field-based optical detection hardware that minimizes sample autofluorescence, this study demonstrates the first optical biosensor system that can continuously measure multiple biomarkers (dopamine and cortisol) in complex samples (artificial cerebrospinal fluid and undiluted plasma) with second and subsecond-scale time responses at physiologically relevant concentration ranges.
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Affiliation(s)
- Amani A Hariri
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Alyssa P Cartwright
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Constantin Dory
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Yasser Gidi
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Steven Yee
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Ian A P Thompson
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Kaiyu X Fu
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Kiyoul Yang
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Diana Wu
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
| | - Nicolò Maganzini
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Trevor Feagin
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Brian E Young
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Behrad Habib Afshar
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
| | | | - Michel J F Digonnet
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Jelena Vuckovic
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - H Tom Soh
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
- Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA
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11
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Myres GJ, Kitt JP, Harris JM. Raman Scattering Reveals Ion-Dependent G-Quadruplex Formation in the 15-mer Thrombin-Binding Aptamer upon Association with α-Thrombin. Anal Chem 2023; 95:16160-16168. [PMID: 37870982 DOI: 10.1021/acs.analchem.3c02751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
The discovery of DNA aptamers that bind biomolecular targets has enabled significant innovations in biosensing. Aptamers form secondary structures that exhibit selective high-affinity interactions with their binding partners. The binding of its target by an aptamer is often accompanied by conformational changes, and sensing by aptamers often relies on these changes to provide readout signals from extrinsic labels to detect target association. Many biosensing applications involve aptamers immobilized to surfaces, but methods to characterize conformations of immobilized aptamers and their in situ response have been lacking. To address this challenge, we have developed a structurally informative Raman spectroscopy method to determine conformations of the 15-mer thrombin-binding aptamer (TBA) immobilized on porous silica surfaces. The TBA is of interest because its binding of α-thrombin depends on the aptamer forming an antiparallel G-quadruplex, which is thought to drive signal changes that allow thrombin-binding to be detected. However, specific metal cations also stabilize the G-quadruplex conformation of the aptamer, even in the absence of its protein target. To develop a deeper understanding of the conformational response of the TBA, we utilize Raman spectroscopy to quantify the effects of the metal cations, K+ (stabilizing) and Li+ (nonstabilizing), on G-quadruplex versus unfolded populations of the TBA. In K+ or Li+ solutions, we then detect the association of α-thrombin with the immobilized aptamer, which can be observed in Raman scattering from the bound protein. The results show that the association of α-thrombin in K+ solutions produces no detectable change in aptamer conformation, which is found in the G-quadruplex form both before and after binding its target. In Li+ solutions, however, where the TBA is unfolded prior to α-thrombin association, protein binding occurs with the formation of a G-quadruplex by the aptamer.
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Affiliation(s)
- Grant J Myres
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, United States
| | - Jay P Kitt
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, United States
| | - Joel M Harris
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, United States
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12
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Wu G, Zhang ET, Qiang Y, Esmonde C, Chen X, Wei Z, Song Y, Zhang X, Schneider MJ, Li H, Sun H, Weng Z, Santaniello S, He J, Lai RY, Li Y, Bruchas MR, Zhang Y. Long-Term In Vivo Molecular Monitoring Using Aptamer-Graphene Microtransistors. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.18.562080. [PMID: 37905115 PMCID: PMC10614860 DOI: 10.1101/2023.10.18.562080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Long-term, real-time molecular monitoring in complex biological environments is critical for our ability to understand, prevent, diagnose, and manage human diseases. Aptamer-based electrochemical biosensors possess the promise due to their generalizability and a high degree of selectivity. Nevertheless, the operation of existing aptamer-based biosensors in vivo is limited to a few hours. Here, we report a first-generation long-term in vivo molecular monitoring platform, named aptamer-graphene microtransistors (AGMs). The AGM incorporates a layer of pyrene-(polyethylene glycol)5-alcohol and DNase inhibitor-doped polyacrylamide hydrogel coating to reduce biofouling and aptamer degradation. As a demonstration of function and generalizability, the AGM achieves the detection of biomolecules such as dopamine and serotonin in undiluted whole blood at 37 °C for 11 days. Furthermore, the AGM successfully captures optically evoked dopamine release in vivo in mice for over one week and demonstrates the capability to monitor behaviorally-induced endogenous dopamine release even after eight days of implantation in freely moving mice. The results reported in this work establish the potential for chronic aptamer-based molecular monitoring platforms, and thus serve as a new benchmark for molecular monitoring using aptamer-based technology.
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Affiliation(s)
- Guangfu Wu
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA
- Institute of Materials Science, University of Connecticut, Storrs, CT 06269, USA
| | - Eric T. Zhang
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
- Center for Neurobiology of Addiction, Pain, and Emotion, University of Washington, Seattle, WA 98195, USA
| | - Yingqi Qiang
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA
- Institute of Materials Science, University of Connecticut, Storrs, CT 06269, USA
| | - Colin Esmonde
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL 32306, USA
| | - Xingchi Chen
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL 32306, USA
| | - Zichao Wei
- Department of Chemistry, University of Connecticut, Storrs, CT 06269, USA
| | - Yang Song
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA
- Institute of Materials Science, University of Connecticut, Storrs, CT 06269, USA
| | - Xincheng Zhang
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA
- Institute of Materials Science, University of Connecticut, Storrs, CT 06269, USA
| | - Michael J. Schneider
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA
| | - Huijie Li
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA
- Institute of Materials Science, University of Connecticut, Storrs, CT 06269, USA
| | - He Sun
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA
- Institute of Materials Science, University of Connecticut, Storrs, CT 06269, USA
| | - Zhengyan Weng
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA
- Institute of Materials Science, University of Connecticut, Storrs, CT 06269, USA
| | - Sabato Santaniello
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA
| | - Jie He
- Department of Chemistry, University of Connecticut, Storrs, CT 06269, USA
| | - Rebecca Y. Lai
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Yan Li
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL 32306, USA
| | - Michael R. Bruchas
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA 98195, USA
- Center for Neurobiology of Addiction, Pain, and Emotion, University of Washington, Seattle, WA 98195, USA
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
| | - Yi Zhang
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA
- Institute of Materials Science, University of Connecticut, Storrs, CT 06269, USA
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13
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Roehrich B, Leung KK, Gerson J, Kippin TE, Plaxco KW, Sepunaru L. Calibration-Free, Seconds-Resolved In Vivo Molecular Measurements using Fourier-Transform Impedance Spectroscopy Interrogation of Electrochemical Aptamer Sensors. ACS Sens 2023; 8:3051-3059. [PMID: 37584531 PMCID: PMC10463274 DOI: 10.1021/acssensors.3c00632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 08/02/2023] [Indexed: 08/17/2023]
Abstract
Electrochemical aptamer-based (EAB) sensors are capable of measuring the concentrations of specific molecules in vivo, in real time, and with a few-second time resolution. For their signal transduction mechanism, these sensors utilize a binding-induced conformational change in their target-recognizing, redox-reporter-modified aptamer to alter the rate of electron transfer between the reporter and the supporting electrode. While a variety of voltammetric techniques have been used to monitor this change in kinetics, they suffer from various drawbacks, including time resolution limited to several seconds and sensor-to-sensor variation that requires calibration to remove. Here, however, we show that the use of fast Fourier transform electrochemical impedance spectroscopy (FFT-EIS) to interrogate EAB sensors leads to improved (here better than 2 s) time resolution and calibration-free operation, even when such sensors are deployed in vivo. To showcase these benefits, we demonstrate the approach's ability to perform real-time molecular measurements in the veins of living rats.
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Affiliation(s)
- Brian Roehrich
- Department
of Chemistry and Biochemistry, University
of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Kaylyn K. Leung
- Department
of Chemistry and Biochemistry, 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, California 93106, United States
- Center
for Bioengineering, 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, California 93106, United States
- Department
of Molecular Cellular and Developmental Biology, University of California, 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
- Center
for Bioengineering, University of California
Santa Barbara, Santa Barbara, California 93106, United States
| | - Lior Sepunaru
- Department
of Chemistry and Biochemistry, University
of California Santa Barbara, Santa Barbara, California 93106, United States
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14
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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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15
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Chang D, Wang Z, Flynn CD, Mahmud A, Labib M, Wang H, Geraili A, Li X, Zhang J, Sargent EH, Kelley SO. A high-dimensional microfluidic approach for selection of aptamers with programmable binding affinities. Nat Chem 2023; 15:773-780. [PMID: 37277648 DOI: 10.1038/s41557-023-01207-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 04/17/2023] [Indexed: 06/07/2023]
Abstract
Aptamers are being applied as affinity reagents in analytical applications owing to their high stability, compact size and amenability to chemical modification. Generating aptamers with different binding affinities is desirable, but systematic evolution of ligands by exponential enrichment (SELEX), the standard for aptamer generation, is unable to quantitatively produce aptamers with desired binding affinities and requires multiple rounds of selection to eliminate false-positive hits. Here we introduce Pro-SELEX, an approach for the rapid discovery of aptamers with precisely defined binding affinities that combines efficient particle display, high-performance microfluidic sorting and high-content bioinformatics. Using the Pro-SELEX workflow, we were able to investigate the binding performance of individual aptamer candidates under different selective pressures in a single round of selection. Using human myeloperoxidase as a target, we demonstrate that aptamers with dissociation constants spanning a 20-fold range of affinities can be identified within one round of Pro-SELEX.
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Affiliation(s)
- Dingran Chang
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Zongjie Wang
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, USA
| | - Connor D Flynn
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
- Department of Chemistry, Weinberg College of Arts & Sciences, Northwestern University, Evanston, IL, USA
| | - Alam Mahmud
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Mahmoud Labib
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
- Department of Chemistry, Weinberg College of Arts & Sciences, Northwestern University, Evanston, IL, USA
- Peninsula Medical School, Faculty of Health, University of Plymouth, Plymouth, UK
| | - Hansen Wang
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Armin Geraili
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Xiangling Li
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Jiaqi Zhang
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Edward H Sargent
- Department of Chemistry, Weinberg College of Arts & Sciences, Northwestern University, Evanston, IL, USA
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada
- Department of Electrical and Computer Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, USA
- International Institute for Nanotechnology, Northwestern University, Evanston, IL, USA
| | - Shana O Kelley
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada.
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, USA.
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada.
- Department of Chemistry, Weinberg College of Arts & Sciences, Northwestern University, Evanston, IL, USA.
- International Institute for Nanotechnology, Northwestern University, Evanston, IL, USA.
- Department of Biochemistry, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
- Simpson Querrey Institute, Northwestern University, Chicago, IL, USA.
- Chan Zuckerberg Biohub Chicago, Chicago, IL, USA.
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16
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Yuan Y, Arroyo-Currás N. Continuous Molecular Monitoring in the Body via Nucleic Acid-based Electrochemical Sensors: The Need for Statistically-powered Validation. CURRENT OPINION IN ELECTROCHEMISTRY 2023; 39:101305. [PMID: 37274549 PMCID: PMC10237360 DOI: 10.1016/j.coelec.2023.101305] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Nucleic acid-based electrochemical (NBE) sensors offer real-time and reagent-free sensing capabilities that overcome limitations of target-specific reactivity via affinity-based molecular detection. By leveraging affinity probes, NBE sensors become modular and versatile, allowing the monitoring of a variety of molecular targets by simply swapping the recognition probe without the need to change their sensor architecture. However, NBE sensors have not been rigorously validated in vivo in terms of analytical performance and clinical agreement relative to benchmark methods. In this article, we highlight reports from the past three years that evaluate NBE sensors performance in vivo. We hope this discussion will inspire future translational efforts with statistically robust experimental design, thus enabling real-world clinical applications and commercial development of NBE sensors.
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Affiliation(s)
- Yuchan Yuan
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21202
| | - Netzahualcóyotl Arroyo-Currás
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21202
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD 21218
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD 21218
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17
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Downs AM, Bolotsky A, Weaver BM, Bennett H, Wolff N, Polsky R, Miller PR. Microneedle electrochemical aptamer-based sensing: Real-time small molecule measurements using sensor-embedded, commercially-available stainless steel microneedles. Biosens Bioelectron 2023; 236:115408. [PMID: 37267688 DOI: 10.1016/j.bios.2023.115408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 05/11/2023] [Accepted: 05/15/2023] [Indexed: 06/04/2023]
Abstract
Microneedle sensors could enable minimally-invasive, continuous molecular monitoring - informing on disease status and treatment in real-time. Wearable sensors for pharmaceuticals, for example, would create opportunities for treatments personalized to individual pharmacokinetics. Here, we demonstrate a commercial-off-the-shelf (COTS) approach for microneedle sensing using an electrochemical aptamer-based sensor that detects the high-toxicity antibiotic, vancomycin. Wearable monitoring of vancomycin could improve patient care by allowing targeted drug dosing within its narrow clinical window of safety and efficacy. To produce sensors, we miniaturize the electrochemical aptamer-based sensors to a microelectrode format, and embed them within stainless steel microneedles (sourced from commercial insulin pen needles). The microneedle sensors achieve quantitative measurements in body-temperature undiluted blood. Further, the sensors effectively maintain electrochemical signal within porcine skin. This COTS approach requires no cleanroom fabrication or specialized equipment, and produces individually-addressable, sterilizable microneedle sensors capable of easily penetrating the skin. In the future, this approach could be adapted for multiplexed detection, enabling real-time monitoring of a range of biomarkers.
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Affiliation(s)
- Alex M Downs
- Biological & Chemical Sensors Department, Sandia National Laboratories, 1515 Eubank Blvd. SE, Albuquerque, New Mexico 87123, USA.
| | - Adam Bolotsky
- Biological & Chemical Sensors Department, Sandia National Laboratories, 1515 Eubank Blvd. SE, Albuquerque, New Mexico 87123, USA
| | - Bryan M Weaver
- Biological & Chemical Sensors Department, Sandia National Laboratories, 1515 Eubank Blvd. SE, Albuquerque, New Mexico 87123, USA
| | - Haley Bennett
- Biological & Chemical Sensors Department, Sandia National Laboratories, 1515 Eubank Blvd. SE, Albuquerque, New Mexico 87123, USA
| | - Nathan Wolff
- Biological & Chemical Sensors Department, Sandia National Laboratories, 1515 Eubank Blvd. SE, Albuquerque, New Mexico 87123, USA
| | - Ronen Polsky
- Biological & Chemical Sensors Department, Sandia National Laboratories, 1515 Eubank Blvd. SE, Albuquerque, New Mexico 87123, USA
| | - Philip R Miller
- Biological & Chemical Sensors Department, Sandia National Laboratories, 1515 Eubank Blvd. SE, Albuquerque, New Mexico 87123, USA
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18
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Flynn CD, Chang D, Mahmud A, Yousefi H, Das J, Riordan KT, Sargent EH, Kelley SO. Biomolecular sensors for advanced physiological monitoring. NATURE REVIEWS BIOENGINEERING 2023; 1:1-16. [PMID: 37359771 PMCID: PMC10173248 DOI: 10.1038/s44222-023-00067-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 04/06/2023] [Indexed: 06/28/2023]
Abstract
Body-based biomolecular sensing systems, including wearable, implantable and consumable sensors allow comprehensive health-related monitoring. Glucose sensors have long dominated wearable bioanalysis applications owing to their robust continuous detection of glucose, which has not yet been achieved for other biomarkers. However, access to diverse biological fluids and the development of reagentless sensing approaches may enable the design of body-based sensing systems for various analytes. Importantly, enhancing the selectivity and sensitivity of biomolecular sensors is essential for biomarker detection in complex physiological conditions. In this Review, we discuss approaches for the signal amplification of biomolecular sensors, including techniques to overcome Debye and mass transport limitations, and selectivity improvement, such as the integration of artificial affinity recognition elements. We highlight reagentless sensing approaches that can enable sequential real-time measurements, for example, the implementation of thin-film transistors in wearable devices. In addition to sensor construction, careful consideration of physical, psychological and security concerns related to body-based sensor integration is required to ensure that the transition from the laboratory to the human body is as seamless as possible.
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Affiliation(s)
- Connor D. Flynn
- Department of Chemistry, Faculty of Arts & Science, University of Toronto, Toronto, ON Canada
- Department of Chemistry, Weinberg College of Arts & Sciences, Northwestern University, Evanston, IL USA
| | - Dingran Chang
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON Canada
| | - Alam Mahmud
- The Edward S. Rogers Sr Department of Electrical and Computer Engineering, University of Toronto, Toronto, ON Canada
| | - Hanie Yousefi
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL USA
| | - Jagotamoy Das
- Department of Chemistry, Weinberg College of Arts & Sciences, Northwestern University, Evanston, IL USA
| | - Kimberly T. Riordan
- Department of Chemistry, Weinberg College of Arts & Sciences, Northwestern University, Evanston, IL USA
| | - Edward H. Sargent
- Department of Chemistry, Weinberg College of Arts & Sciences, Northwestern University, Evanston, IL USA
- The Edward S. Rogers Sr Department of Electrical and Computer Engineering, University of Toronto, Toronto, ON Canada
- Department of Electrical and Computer Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL USA
| | - Shana O. Kelley
- Department of Chemistry, Faculty of Arts & Science, University of Toronto, Toronto, ON Canada
- Department of Chemistry, Weinberg College of Arts & Sciences, Northwestern University, Evanston, IL USA
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON Canada
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL USA
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Evanston, IL USA
- International Institute for Nanotechnology, Northwestern University, Evanston, IL USA
- Chan Zuckerberg Biohub Chicago, Chicago, IL USA
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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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Leung KK, Gerson J, Emmons N, Roehrich B, Verrinder E, Fetter LC, Kippin TE, Plaxco KW. A tight squeeze: geometric effects on the performance of three-electrode electrochemical-aptamer based sensors in constrained, in vivo placements. Analyst 2023; 148:1562-1569. [PMID: 36891771 DOI: 10.1039/d2an02096c] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
Electrochemical, aptamer-based (EAB) sensors are the first molecular monitoring technology that is (1) based on receptor binding and not the reactivity of the target, rendering it fairly general, and (2) able to support high-frequency, real-time measurements in situ in the living body. To date, EAB-derived in vivo measurements have largely been performed using three electrodes (working, reference, counter) bundled together within a catheter for insertion into the rat jugular. Exploring this architecture, here we show that the placement of these electrodes inside or outside of the lumen of the catheter significantly impacts sensor performance. Specifically, we find that retaining the counter electrode within the catheter increases the resistance between it and the working electrode, increasing the capacitive background. In contrast, extending the counter electrode outside the lumen of the catheter reduces this effect, significantly enhancing the signal-to-noise of intravenous molecular measurements. Exploring counter electrode geometries further, we find that they need not be larger than the working electrode. Putting these observations together, we have developed a new intravenous EAB architecture that achieves improved performance while remaining short enough to safely emplace in the rat jugular. These findings, though explored here with EAB sensors may prove important for the design of many electrochemical biosensors.
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Affiliation(s)
- Kaylyn K Leung
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, CA 93106, USA. .,Center for Bioengineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Julian Gerson
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA 93106, USA.,Center for Bioengineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Nicole Emmons
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA 93106, USA.,Center for Bioengineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Brian Roehrich
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, CA 93106, USA.
| | - Elsi Verrinder
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, CA 93106, USA. .,Center for Bioengineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Lisa C Fetter
- Biomolecular Sciences and Engineering, University of California, Santa Barbara, California 93106, USA.,Center for Bioengineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Tod E Kippin
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA 93106, USA.,Department of Molecular Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Kevin W Plaxco
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, CA 93106, USA. .,Biomolecular Sciences and Engineering, University of California, Santa Barbara, California 93106, USA.,Center for Bioengineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA
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21
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Parolo C, Idili A, Heikenfeld J, Plaxco KW. Conformational-switch biosensors as novel tools to support continuous, real-time molecular monitoring in lab-on-a-chip devices. LAB ON A CHIP 2023; 23:1339-1348. [PMID: 36655710 PMCID: PMC10799767 DOI: 10.1039/d2lc00716a] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Recent years have seen continued expansion of the functionality of lab on a chip (LOC) devices. Indeed LOCs now provide scientists and developers with useful and versatile platforms across a myriad of chemical and biological applications. The field still fails, however, to integrate an often important element of bench-top analytics: real-time molecular measurements that can be used to "guide" a chemical response. Here we describe the analytical techniques that could provide LOCs with such real-time molecular monitoring capabilities. It appears to us that, among the approaches that are general (i.e., that are independent of the reactive or optical properties of their targets), sensing strategies relying on binding-induced conformational change of bioreceptors are most likely to succeed in such applications.
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Affiliation(s)
- Claudio Parolo
- Barcelona Institute for Global Health, Hospital Clínic Universitat de Barcelona, 08036, Barcelona, Spain
| | - Andrea Idili
- Department of Chemical Science and Technologies, University of Rome, Tor Vergata, 00133 Rome, Italy
| | - Jason Heikenfeld
- Novel Devices Laboratory, University of Cincinnati, Cincinnati, Ohio, USA
| | - Kevin W Plaxco
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California, USA.
- Interdepartmental Program in Biomolecular Science and Engineering, University of California Santa Barbara, Santa Barbara, California, USA
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22
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Flatebo C, Conkright WR, Beckner ME, Batchelor RH, Kippin TE, Heikenfeld J, Plaxco KW. Efforts toward the continuous monitoring of molecular markers of performance. J Sci Med Sport 2023:S1440-2440(23)00028-2. [PMID: 36841706 DOI: 10.1016/j.jsams.2023.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 01/04/2023] [Accepted: 01/28/2023] [Indexed: 02/05/2023]
Abstract
OBJECTIVES Technologies supporting the continuous, real-time measurement of blood oxygen saturation and plasma glucose levels have improved our ability to monitor performance status. Our ability to monitor other molecular markers of performance, however, including the hormones known to indicate overtraining and general health, has lagged. That is, although a number of other molecular markers of performance status have been identified, we have struggled to develop viable technologies supporting their real-time monitoring in the body. Here we review biosensor approaches that may support such measurements, as well as the molecules potentially of greatest interest to monitor. DESIGN Narrative literature review. METHOD Literature review. RESULTS Significant effort has been made to harness the specificity, affinity, and generalizability of biomolecular recognition in a platform technology supporting continuous in vivo molecular measurements. Most biosensor approaches, however, are either not generalizable to most targets, or fail when challenged in the complex environments found in vivo. Electrochemical aptamer-based sensors, in contrast, are the first technology to simultaneously achieve both of these critical attributes. In an effort to illustrate the potential of this platform technology, we both critically review the literature describing it and briefly survey some of the molecular performance markers we believe will prove advantageous to monitor using it. CONCLUSIONS Electrochemical aptamer-based sensors may be the first truly generalizable technology for monitoring specific molecules in situ in the body and how adaptation of the platform to subcutaneous microneedles will enable the real-time monitoring of performance markers via a wearable, minimally invasive device.
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Affiliation(s)
- Charlotte Flatebo
- Institute for Collaborative Biotechnologies, University of California Santa Barbara, USA
| | | | | | | | - Tod E Kippin
- Neuroscience Research Institute, Department of Psychological and Brain Sciences, University of California Santa Barbara, USA
| | - Jason Heikenfeld
- Biomedical, Electrical, and Chemical Engineering, Director Novel Devices Laboratory, University of Cincinnati, USA
| | - Kevin W Plaxco
- Institute for Collaborative Biotechnologies, University of California Santa Barbara, USA; Department of Chemistry and Biochemistry, Biological Engineering Graduate Program, University of California Santa Barbara, USA.
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23
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Chamorro-Garcia A, Gerson J, Flatebo C, Fetter L, Downs AM, Emmons N, Ennis HL, Milosavić N, Yang K, Stojanovic M, Ricci F, Kippin TE, Plaxco KW. Real-Time, Seconds-Resolved Measurements of Plasma Methotrexate In Situ in the Living Body. ACS Sens 2023; 8:150-157. [PMID: 36534756 DOI: 10.1021/acssensors.2c01894] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Dose-limiting toxicity and significant patient-to-patient pharmacokinetic variability often render it difficult to achieve the safe and effective dosing of drugs. This is further compounded by the slow, cumbersome nature of the analytical methods used to monitor patient-specific pharmacokinetics, which inevitably rely on blood draws followed by post-facto laboratory analysis. Motivated by the pressing need for improved "therapeutic drug monitoring", we are developing electrochemical aptamer-based (EAB) sensors, a minimally invasive biosensor architecture that can provide real-time, seconds-resolved measurements of drug levels in situ in the living body. A key advantage of EAB sensors is that they are generalizable to the detection of a wide range of therapeutic agents because they are independent of the chemical or enzymatic reactivity of their targets. Three of the four therapeutic drug classes that have, to date, been shown measurable using in vivo EAB sensors, however, bind to nucleic acids as part of their mode of action, leaving open questions regarding the extent to which the approach can be generalized to therapeutics that do not. Here, we demonstrate real-time, in vivo measurements of plasma methotrexate, an antimetabolite (a mode of action not reliant on DNA binding) chemotherapeutic, following human-relevant dosing in a live rat animal model. By providing hundreds of drug concentration values, the resulting seconds-resolved measurements succeed in defining key pharmacokinetic parameters, including the drug's elimination rate, peak plasma concentration, and exposure (area under the curve), with unprecedented 5 to 10% precision. With this level of precision, we easily identify significant (>2-fold) differences in drug exposure occurring between even healthy rats given the same mass-adjusted methotrexate dose. By providing a real-time, seconds-resolved window into methotrexate pharmacokinetics, such measurements can be used to precisely "individualize" the dosing of this significantly toxic yet vitally important chemotherapeutic.
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Affiliation(s)
- Alejandro Chamorro-Garcia
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States.,Dipartimento di Scienze e Tecnologie Chimiche, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Julian Gerson
- Department of Psychological and Brain Sciences, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Charlotte Flatebo
- Institute for Collaborative Biotechnologies, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Lisa Fetter
- Biomolecular Science and Engineering Program, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Alex M Downs
- Department of Mechanical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Nicole Emmons
- Department of Psychological and Brain Sciences, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Herbert L Ennis
- Center for Innovative Diagnostic and Therapeutic Approaches, Department of Medicine, Columbia University New York, New York, New York 10032, United States
| | - Nenad Milosavić
- Center for Innovative Diagnostic and Therapeutic Approaches, Department of Medicine, Columbia University New York, New York, New York 10032, United States
| | - Kyungae Yang
- Center for Innovative Diagnostic and Therapeutic Approaches, Department of Medicine, Columbia University New York, New York, New York 10032, United States
| | - Milan Stojanovic
- Center for Innovative Diagnostic and Therapeutic Approaches, Department of Medicine, Columbia University New York, New York, New York 10032, United States.,Department of Biomedical Engineering and Systems Biology, Columbia University New York, New York, New York 10032, United States
| | - Francesco Ricci
- Dipartimento di Scienze e Tecnologie Chimiche, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Tod E Kippin
- Department of Psychological and Brain Sciences, 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.,Biomolecular Science and Engineering Program, University of California Santa Barbara, Santa Barbara, California 93106, United States.,Department of Mechanical Engineering, 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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24
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Wu Y, Ranallo S, Del Grosso E, Chamoro-Garcia A, Ennis HL, Milosavić N, Yang K, Kippin T, Ricci F, Stojanovic M, Plaxco KW. Using Spectroscopy to Guide the Adaptation of Aptamers into Electrochemical Aptamer-Based Sensors. Bioconjug Chem 2023; 34:124-132. [PMID: 36044602 PMCID: PMC10799766 DOI: 10.1021/acs.bioconjchem.2c00275] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Electrochemical aptamer-based (EAB) sensors utilize the binding-induced conformational change of an electrode-attached, redox-reporter-modified aptamer to transduce target recognition into an easily measurable electrochemical output. Because this signal transduction mechanism is single-step and rapidly reversible, EAB sensors support high-frequency, real-time molecular measurements, and because it recapitulates the reagentless, conformation-linked signaling seen in vivo among naturally occurring receptors, EAB sensors are selective enough to work in the complex, time-varying environments found in the living body. The fabrication of EAB sensors, however, requires that their target-recognizing aptamer be modified such that (1) it undergoes the necessary binding-induced conformational change and (2) that the thermodynamics of this "conformational switch" are tuned to ensure that they reflect an acceptable trade-off between affinity and signal gain. That is, even if an "as-selected" aptamer achieves useful affinity and specificity, it may fail when adapted to the EAB platform because it lacks the binding-induced conformational change required to support EAB signaling. In this paper we reveal the spectroscopy-guided approaches we use to modify aptamers such that they support the necessary binding-induced conformational change. Specifically, using newly reported aptamers, we demonstrate the systematic design of EAB sensors achieving clinically and physiologically relevant specificity, limits of detection, and dynamic range against the targets methotrexate and tryptophan.
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Affiliation(s)
- Yuyang Wu
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Simona Ranallo
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
- Chemistry Department, University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy
| | - Erica Del Grosso
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
- Chemistry Department, University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy
| | - Alejandro Chamoro-Garcia
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
- Chemistry Department, University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy
| | - Herbert L Ennis
- Department of Medicine, Columbia University, New York, New York 10032, United States
| | - Nenad Milosavić
- Department of Medicine, Columbia University, New York, New York 10032, United States
| | - Kyungae Yang
- Department of Medicine, Columbia University, New York, New York 10032, United States
| | - Tod 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, Santa Barbara, California 93106, United States
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Francesco Ricci
- Chemistry Department, University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy
| | - Milan Stojanovic
- Department of Medicine, Columbia University, New York, New York 10032, United States
- Department of Biomedical Engineering and Systems Biology, Columbia University, New York, New York 10032, 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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25
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Ming T, Luo J, Xing Y, Cheng Y, Liu J, Sun S, Kong F, Xu S, Dai Y, Xie J, Jin H, Cai X. Recent progress and perspectives of continuous in vivo testing device. Mater Today Bio 2022; 16:100341. [PMID: 35875195 PMCID: PMC9305619 DOI: 10.1016/j.mtbio.2022.100341] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 06/22/2022] [Accepted: 06/23/2022] [Indexed: 11/26/2022] Open
Abstract
Devices for continuous in-vivo testing (CIVT) can detect target substances in real time, thus providing a valuable window into a patient's condition, their response to therapeutics, metabolic activities, and neurotransmitter transmission in the brain. Therefore, CIVT devices have received increased attention because they are expected to greatly assist disease diagnosis and treatment and research on human pathogenesis. However, CIVT has been achieved for only a few markers, and it remains challenging to detect many key markers. Therefore, it is important to summarize the key technologies and methodologies of CIVT, and to examine the direction of future development of CIVT. We review recent progress in the development of CIVT devices, with consideration of the structure of these devices, principles governing continuous detection, and nanomaterials used for electrode modification. This detailed and comprehensive review of CIVT devices serves three purposes: (1) to summarize the advantages and disadvantages of existing devices, (2) to provide a reference for development of CIVT equipment to detect additional important markers, and (3) to discuss future prospects with emphasis on problems that must be overcome for further development of CIVT equipment. This review aims to promote progress in research on CIVT devices and contribute to future innovation in personalized medical treatments.
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Affiliation(s)
- Tao Ming
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100094, PR China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jinping Luo
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100094, PR China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yu Xing
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100094, PR China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yan Cheng
- Obstetrics and Gynecology Department, Peking University First Hospital, Beijing, 100034, PR China
| | - Juntao Liu
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100094, PR China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shuai Sun
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100094, PR China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Fanli Kong
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100094, PR China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shihong Xu
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100094, PR China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yuchuan Dai
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100094, PR China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jingyu Xie
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100094, PR China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hongyan Jin
- Obstetrics and Gynecology Department, Peking University First Hospital, Beijing, 100034, PR China
| | - Xinxia Cai
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100094, PR China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
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26
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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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27
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Chamorro-Garcia A, Parolo C, Ortega G, Idili A, Green J, Ricci F, Plaxco KW. The sequestration mechanism as a generalizable approach to improve the sensitivity of biosensors and bioassays. Chem Sci 2022; 13:12219-12228. [PMID: 36349092 PMCID: PMC9601244 DOI: 10.1039/d2sc03901j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 09/16/2022] [Indexed: 07/25/2023] Open
Abstract
Biosensors and bioassays, both of which employ proteins and nucleic acids to detect specific molecular targets, have seen significant applications in both biomedical research and clinical practice. This success is largely due to the extraordinary versatility, affinity, and specificity of biomolecular recognition. Nevertheless, these receptors suffer from an inherent limitation: single, saturable binding sites exhibit a hyperbolic relationship (the "Langmuir isotherm") between target concentration and receptor occupancy, which in turn limits the sensitivity of these technologies to small variations in target concentration. To overcome this and generate more responsive biosensors and bioassays, here we have used the sequestration mechanism to improve the steepness of the input/output curves of several bioanalytical methods. As our test bed for this we employed sensors and assays against neutrophil gelatinase-associated lipocalin (NGAL), a kidney biomarker for which enhanced sensitivity will improve the monitoring of kidney injury. Specifically, by introducing sequestration we have improved the responsiveness of an electrochemical aptamer based (EAB) biosensor, and two bioassays, a paper-based "dipstick" assay and an enzyme-linked immunosorbent assay (ELISA). Doing so we have narrowed the dynamic range of these sensors and assays several-fold, thus enhancing their ability to measure small changes in target concentration. Given that introducing sequestration requires only the addition of the appropriate concentration of a high-affinity "depletant," the mechanism appears simple and easily adaptable to tuning the binding properties of the receptors employed in a wide range of biosensors and bioassays.
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Affiliation(s)
- Alejandro Chamorro-Garcia
- Department of Chemistry and Biochemistry University of California Santa Barbara (UCSB) Santa Barbara CA 93106 USA
- Dipartimento di Scienze e Tecnologie Chimiche, University of Rome, Tor Vergata, Via della Ricerca Scientifica 00133 Rome Italy
| | - Claudio Parolo
- ISGlobal-Barcelona Institute for Global Health Carrer del Rosselló 132 08036 Barcelona Spain
| | - Gabriel Ortega
- Ikerbasque, Basque Foundation for Science 48013 Bilbao Spain
- Precision Medicine and Metabolism Laboratory, CIC BioGUNE, Basque Research and Technology Alliance, Parque Tecnológico de Bizkaia 48160 Derio Spain
| | - Andrea Idili
- Dipartimento di Scienze e Tecnologie Chimiche, University of Rome, Tor Vergata, Via della Ricerca Scientifica 00133 Rome Italy
| | - Joshua Green
- Department of Chemistry and Biochemistry University of California Santa Barbara (UCSB) Santa Barbara CA 93106 USA
| | - Francesco Ricci
- Dipartimento di Scienze e Tecnologie Chimiche, University of Rome, Tor Vergata, Via della Ricerca Scientifica 00133 Rome Italy
| | - Kevin W Plaxco
- Department of Chemistry and Biochemistry University of California Santa Barbara (UCSB) Santa Barbara CA 93106 USA
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28
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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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29
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Downs AM, Gerson J, Leung KK, Honeywell KM, Kippin T, Plaxco KW. Improved calibration of electrochemical aptamer-based sensors. Sci Rep 2022; 12:5535. [PMID: 35365672 PMCID: PMC8976050 DOI: 10.1038/s41598-022-09070-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 02/24/2022] [Indexed: 12/22/2022] Open
Abstract
Electrochemical aptamer-based (EAB) sensors support the real-time, high frequency measurement of pharmaceuticals and metabolites in-situ in the living body, rendering them a potentially powerful technology for both research and clinical applications. Here we explore quantification using EAB sensors, examining the impact of media selection and temperature on measurement performance. Using freshly-collected, undiluted whole blood at body temperature as both our calibration and measurement conditions, we demonstrate accuracy of better than ± 10% for the measurement of our test bed drug, vancomycin. Comparing titrations collected at room and body temperature, we find that matching the temperature of calibration curve collection to the temperature used during measurements improves quantification by reducing differences in sensor gain and binding curve midpoint. We likewise find that, because blood age impacts the sensor response, calibrating in freshly collected blood can improve quantification. Finally, we demonstrate the use of non-blood proxy media to achieve calibration without the need to collect fresh whole blood.
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Affiliation(s)
- Alex M Downs
- Department of Mechanical Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA.,Center for Bioengineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Julian Gerson
- Department of Psychological and Brain Sciences, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Kaylyn K Leung
- 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
| | - Kevin M Honeywell
- Department of Psychological and Brain Sciences, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Tod Kippin
- Department of Psychological and Brain Sciences, University of California Santa Barbara, Santa Barbara, CA, 93106, USA.,The Neuroscience Research Institute and Department of Molecular Cellular and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Kevin W Plaxco
- Department of Mechanical Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA. .,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.
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30
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Chung J, Sepunaru L, Plaxco KW. On the Disinfection of Electrochemical Aptamer-Based Sensors. ECS SENSORS PLUS 2022; 1. [PMID: 36452064 PMCID: PMC9703871 DOI: 10.1149/2754-2726/ac60b2] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Electrochemical aptamer-based (EAB) sensors encompass the only biosensor approach yet reported that is simultaneously: (1) independent of the chemical or enzymatic reactivity of its target, rendering it general; (2) continuous and real-time; and (3) selective enough to deploy in situ in the living body. Consistent with this, in vivo EAB sensors supporting the seconds-resolved, real-time measurement of multiple drugs and metabolites have been reported, suggesting the approach may prove of value in biomedical research and the diagnosis, treatment, and monitoring of disease. However, to apply these devices in long-duration animal models, much less in human patients, requires that they be free of any significant pathogen load. Thus motivated, here we have characterized the compatibility of EAB sensors with standard sterilization and high-level disinfection techniques. Doing so, we find that, while many lead to significant sensor degradation, treatment with CIDEX OPA (0.55% ortho-phthalaldehyde) leads to effective disinfection without causing any detectable loss in sensor performance.
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Affiliation(s)
- Julia Chung
- Interdepartmental Program in Biomedical Science and Engineering, University of California at Santa Barbara, Santa Barbara, California 93106, USA
| | - Lior Sepunaru
- Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, California 93106, USA
| | - Kevin W. Plaxco
- Interdepartmental Program in Biomedical Science and Engineering, University of California at Santa Barbara, Santa Barbara, California 93106, USA
- Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, California 93106, USA
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Idili A, Montón H, Medina-Sánchez M, Ibarlucea B, Cuniberti G, Schmidt OG, Plaxco KW, Parolo C. Continuous monitoring of molecular biomarkers in microfluidic devices. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2022; 187:295-333. [PMID: 35094779 DOI: 10.1016/bs.pmbts.2021.07.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The ability to monitor molecular targets is crucial in fields ranging from healthcare to industrial processing to environmental protection. Devices employing biomolecules to achieve this goal are called biosensors. Over the last half century researchers have developed dozens of different biosensor approaches. In this chapter we analyze recent advances in the biosensing field aiming at adapting these to the problem of continuous molecular monitoring in complex sample streams, and how the merging of these sensors with lab-on-a-chip technologies would be beneficial to both. To do so we discuss (1) the components that comprise a biosensor, (2) the challenges associated with continuous molecular monitoring in complex sample streams, (3) how different sensing strategies deal with (or fail to deal with) these challenges, and (4) the implementation of these technologies into lab-on-a-chip architectures.
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Affiliation(s)
- Andrea Idili
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, United States; Department of Chemical Science and Technologies, University of Rome, Tor Vergata, Rome, Italy
| | - Helena Montón
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, United States
| | | | - Bergoi Ibarlucea
- Institute for Materials Science and Max Bergmann Center for Biomaterials, Technische Universität Dresden, Dresden, Germany; Center for Advancing Electronics Dresden (CFAED), Technische Universität Dresden, Dresden, Germany
| | - Gianaurelio Cuniberti
- Institute for Materials Science and Max Bergmann Center for Biomaterials, Technische Universität Dresden, Dresden, Germany; Center for Advancing Electronics Dresden (CFAED), Technische Universität Dresden, Dresden, Germany
| | - Oliver G Schmidt
- Institute for Integrative Nanosciences, Leibniz IFW Dresden, Dresden, Germany; Research Center for Materials, Architectures and Integration of Nanomembranes (MAIN), Chemnitz, Germany; School of Science, TU Dresden, Dresden, Germany
| | - Kevin W Plaxco
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, United States; Interdepartmental Program in Biomolecular Science and Engineering University of California, Santa Barbara, CA, United States
| | - Claudio Parolo
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, United States; Barcelona Institute for Global Health (ISGlobal) Hospital Clínic, Barcelona, Spain.
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Dillen A, Lammertyn J. Paving the way towards continuous biosensing by implementing affinity-based nanoswitches on state-dependent readout platforms. Analyst 2022; 147:1006-1023. [DOI: 10.1039/d1an02308j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Combining affinity-based nanoswitches with state-dependent readout platforms allows for continuous biosensing and acquisition of real-time information about biochemical processes occurring in the environment of interest.
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Affiliation(s)
- Annelies Dillen
- KU Leuven, Department of Biosystems – Biosensors Group, Willem de Croylaan 42, Box 2428, 3001, Leuven, Belgium
| | - Jeroen Lammertyn
- KU Leuven, Department of Biosystems – Biosensors Group, Willem de Croylaan 42, Box 2428, 3001, Leuven, Belgium
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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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Leung KK, Downs AM, Ortega G, Kurnik M, Plaxco KW. Elucidating the Mechanisms Underlying the Signal Drift of Electrochemical Aptamer-Based Sensors in Whole Blood. ACS Sens 2021; 6:3340-3347. [PMID: 34491055 DOI: 10.1021/acssensors.1c01183] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The ability to monitor drugs, metabolites, hormones, and other biomarkers in situ in the body would greatly advance both clinical practice and biomedical research. To this end, we are developing electrochemical aptamer-based (EAB) sensors, a platform technology able to perform real-time, in vivo monitoring of specific molecules irrespective of their chemical or enzymatic reactivity. An important obstacle to the deployment of EAB sensors in the challenging environments found in the living body is signal drift, whereby the sensor signal decreases over time. To date, we have demonstrated a number of approaches by which this drift can be corrected sufficiently well to achieve good measurement precision over multihour in vivo deployments. To achieve a much longer in vivo measurement duration, however, will likely require that we understand and address the sources of this effect. In response, here, we have systematically examined the mechanisms underlying the drift seen when EAB sensors and simpler, EAB-like devices are challenged in vitro at 37 °C in whole blood as a proxy for in vivo conditions. Our results demonstrate that electrochemically driven desorption of a self-assembled monolayer and fouling by blood components are the two primary sources of signal loss under these conditions, suggesting targeted approaches to remediating this degradation and thus improving the stability of EAB sensors and other, similar electrochemical biosensor technologies when deployed in the body.
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Affiliation(s)
- Kaylyn K. Leung
- Department of Chemistry and Biochemistry, 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
| | - Alex M. Downs
- Center for Bioengineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
- Department of Mechanical Engineering, 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
- Center for Bioengineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Martin Kurnik
- Department of Chemistry and Biochemistry, 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
| | - Kevin W. Plaxco
- Department of Chemistry and Biochemistry, 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 Mechanical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
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Idili A, Parolo C, Alvarez-Diduk R, Merkoçi A. Rapid and Efficient Detection of the SARS-CoV-2 Spike Protein Using an Electrochemical Aptamer-Based Sensor. ACS Sens 2021; 6:3093-3101. [PMID: 34375076 PMCID: PMC8370117 DOI: 10.1021/acssensors.1c01222] [Citation(s) in RCA: 106] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
![]()
The
availability of sensors able to rapidly detect SARS-CoV-2 directly
in biological fluids in a single step would allow performing massive
diagnostic testing to track in real time and contain the spread of
COVID-19. Motivated by this, here, we developed an electrochemical
aptamer-based (EAB) sensor able to achieve the rapid, reagentless,
and quantitative measurement of the SARS-CoV-2 spike (S) protein.
First, we demonstrated the ability of the selected aptamer to undergo
a binding-induced conformational change in the presence of its target
using fluorescence spectroscopy. Then, we engineered the aptamer to
work as a bioreceptor in the EAB platform and we demonstrated its
sensitivity and specificity. Finally, to demonstrate the clinical
potential of the sensor, we tested it directly in biological fluids
(serum and artificial saliva), achieving the rapid (minutes) and single-step
detection of the S protein in its clinical range.
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Affiliation(s)
- Andrea Idili
- Institut Català de Nanociència i Nanotecnologia (ICN2), Campus UAB, Bellaterra 08193 Barcelona, Spain
| | - Claudio Parolo
- Institut Català de Nanociència i Nanotecnologia (ICN2), Campus UAB, Bellaterra 08193 Barcelona, Spain
- Barcelona Institute for Global Health, 08036 Barcelona, Spain
| | - Ruslán Alvarez-Diduk
- Institut Català de Nanociència i Nanotecnologia (ICN2), Campus UAB, Bellaterra 08193 Barcelona, Spain
| | - Arben Merkoçi
- Institut Català de Nanociència i Nanotecnologia (ICN2), Campus UAB, Bellaterra 08193 Barcelona, Spain
- CSIC and the Barcelona Institute of Science and Technology (BIST), 08036 Barcelona, Spain
- Institucio′ Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
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