1
|
Ye C, Lukas H, Wang M, Lee Y, Gao W. Nucleic acid-based wearable and implantable electrochemical sensors. Chem Soc Rev 2024. [PMID: 38985007 DOI: 10.1039/d4cs00001c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2024]
Abstract
The rapid advancements in nucleic acid-based electrochemical sensors for implantable and wearable applications have marked a significant leap forward in the domain of personal healthcare over the last decade. This technology promises to revolutionize personalized healthcare by facilitating the early diagnosis of diseases, monitoring of disease progression, and tailoring of individual treatment plans. This review navigates through the latest developments in this field, focusing on the strategies for nucleic acid sensing that enable real-time and continuous biomarker analysis directly in various biofluids, such as blood, interstitial fluid, sweat, and saliva. The review delves into various nucleic acid sensing strategies, emphasizing the innovative designs of biorecognition elements and signal transduction mechanisms that enable implantable and wearable applications. Special perspective is given to enhance nucleic acid-based sensor selectivity and sensitivity, which are crucial for the accurate detection of low-level biomarkers. The integration of such sensors into implantable and wearable platforms, including microneedle arrays and flexible electronic systems, actualizes their use in on-body devices for health monitoring. We also tackle the technical challenges encountered in the development of these sensors, such as ensuring long-term stability, managing the complexity of biofluid dynamics, and fulfilling the need for real-time, continuous, and reagentless detection. In conclusion, the review highlights the importance of these sensors in the future of medical engineering, offering insights into design considerations and future research directions to overcome existing limitations and fully realize the potential of nucleic acid-based electrochemical sensors for healthcare applications.
Collapse
Affiliation(s)
- Cui Ye
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA.
| | - Heather Lukas
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA.
| | - Minqiang Wang
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA.
| | - Yerim Lee
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA.
| | - Wei Gao
- Andrew and Peggy Cherng Department of Medical Engineering, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA.
| |
Collapse
|
2
|
Pei S, Babity S, Sara Cordeiro A, Brambilla D. Integrating microneedles and sensing strategies for diagnostic and monitoring applications: The state of the art. Adv Drug Deliv Rev 2024; 210:115341. [PMID: 38797317 DOI: 10.1016/j.addr.2024.115341] [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: 02/17/2024] [Revised: 04/23/2024] [Accepted: 05/18/2024] [Indexed: 05/29/2024]
Abstract
Microneedles (MNs) offer minimally-invasive access to interstitial fluid (ISF) - a potent alternative to blood in terms of monitoring physiological analytes. This property is particularly advantageous for the painless detection and monitoring of drugs and biomolecules. However, the complexity of the skin environment, coupled with the inherent nature of the analytes being detected and the inherent physical properties of MNs, pose challenges when conducting physiological monitoring using this fluid. In this review, we discuss different sensing mechanisms and highlight advancements in monitoring different targets, with a particular focus on drug monitoring. We further list the current challenges facing the field and conclude by discussing aspects of MN design which serve to enhance their performance when monitoring different classes of analytes.
Collapse
Affiliation(s)
- Shihao Pei
- Faculté de pharmacie, Université de Montréal, 2940 Chemin de Polytechnique, Montréal, Québec H3T 1J4, Canada
| | - Samuel Babity
- Faculté de pharmacie, Université de Montréal, 2940 Chemin de Polytechnique, Montréal, Québec H3T 1J4, Canada
| | - Ana Sara Cordeiro
- Leicester Institute for Pharmaceutical Innovation, Leicester School of Pharmacy, De Montfort University, Leicester LE1 9BH, United Kingdom.
| | - Davide Brambilla
- Faculté de pharmacie, Université de Montréal, 2940 Chemin de Polytechnique, Montréal, Québec H3T 1J4, Canada.
| |
Collapse
|
3
|
Arroyo-Currás N. Beyond the Gold-Thiol Paradigm: Exploring Alternative Interfaces for Electrochemical Nucleic Acid-Based Sensing. ACS Sens 2024; 9:2228-2236. [PMID: 38661283 PMCID: PMC11129698 DOI: 10.1021/acssensors.4c00331] [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: 02/12/2024] [Revised: 04/04/2024] [Accepted: 04/16/2024] [Indexed: 04/26/2024]
Abstract
Nucleic acid-based electrochemical sensors (NBEs) use oligonucleotides as affinity reagents for the detection of a variety of targets, ranging from small-molecule therapeutics to whole viruses. Because of their versatility in molecular sensing, NBEs are being developed broadly for diagnostic and biomedical research applications. Benchmark NBEs are fabricated via self-assembly of thiol-based monolayers on gold. Although robust for rapid prototyping, thiol monolayers suffer from limitations in terms of stability under voltage modulation and in the face of competitive ligands such as thiolated molecules naturally occurring in biofluids. Additionally, gold cannot be deployed as an NBE substrate for all biomedical applications, such as in cases where molecular measurements coupled to real-time, under-the-sensor tissue imaging is needed. Seeking to overcome these limitations, the field of NBEs is pursuing alternative ligands and electrode surfaces. In this perspective, I discuss new interface fabrication strategies that have successfully achieved NBE sensing, or that have the potential to allow NBE sensing on conductive surfaces other than gold. I hope this perspective will provide the reader with a fresh view of how future NBE interfaces could be constructed and will serve as inspiration for the pursuit of collaborative developments in the field of NBEs.
Collapse
Affiliation(s)
- Netzahualcóyotl Arroyo-Currás
- Department of Pharmacology
and Molecular
Sciences, Johns Hopkins University School
of Medicine, Baltimore, Maryland 21205, United States
| |
Collapse
|
4
|
Weber CJ, Clay OM, Lycan RE, Anderson GK, Simoska O. Advances in electrochemical biosensor design for the detection of the stress biomarker cortisol. Anal Bioanal Chem 2024; 416:87-106. [PMID: 37989847 DOI: 10.1007/s00216-023-05047-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/30/2023] [Accepted: 11/08/2023] [Indexed: 11/23/2023]
Abstract
The monitoring of stress levels in humans has become increasingly relevant, given the recent incline of stress-related mental health disorders, lifestyle impacts, and chronic physiological diseases. Long-term exposure to stress can induce anxiety and depression, heart disease, and risky behaviors, such as drug and alcohol abuse. Biomarker molecules can be quantified in biological fluids to study human stress. Cortisol, specifically, is a hormone biomarker produced in the adrenal glands with biofluid concentrations that directly correlate to stress levels in humans. The rapid, real-time detection of cortisol is necessary for stress management and predicting the onset of psychological and physical ailments. Current methods, including mass spectrometry and immunoassays, are effective for sensitive cortisol quantification. However, these techniques provide only single measurements which pose challenges in the continuous monitoring of stress levels. Additionally, these analytical methods often require trained personnel to operate expensive instrumentation. Alternatively, low-cost electrochemical biosensors enable the real-time detection and continuous monitoring of cortisol levels while also providing adequate analytical figures of merit (e.g., sensitivity, selectivity, sensor response times, detection limits, and reproducibility) in a simple design platform. This review discusses the recent developments in electrochemical biosensor design for the detection of cortisol in human biofluids. Special emphasis is given to biosensor recognition elements, including antibodies, molecularly imprinted polymers (MIPs), and aptamers, as critical components of electrochemical biosensors for cortisol detection. Furthermore, the advantages and limiting factors of various electrochemical techniques and sensing in complex biofluid matrices are overviewed. Remarks on the current challenges and future perspectives regarding electrochemical biosensors for stress monitoring are provided, including matrix effects (pH dependence and biological interferences), wearability, and large-scale production.
Collapse
Affiliation(s)
- Courtney J Weber
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Olivia M Clay
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Reese E Lycan
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Gracie K Anderson
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Olja Simoska
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA.
| |
Collapse
|
5
|
Watkins Z, McHenry A, Heikenfeld J. Wearing the Lab: Advances and Challenges in Skin-Interfaced Systems for Continuous Biochemical Sensing. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2024; 187:223-282. [PMID: 38273210 DOI: 10.1007/10_2023_238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2024]
Abstract
Continuous, on-demand, and, most importantly, contextual data regarding individual biomarker concentrations exemplify the holy grail for personalized health and performance monitoring. This is well-illustrated for continuous glucose monitoring, which has drastically improved outcomes and quality of life for diabetic patients over the past 2 decades. Recent advances in wearable biosensing technologies (biorecognition elements, transduction mechanisms, materials, and integration schemes) have begun to make monitoring of other clinically relevant analytes a reality via minimally invasive skin-interfaced devices. However, several challenges concerning sensitivity, specificity, calibration, sensor longevity, and overall device lifetime must be addressed before these systems can be made commercially viable. In this chapter, a logical framework for developing a wearable skin-interfaced device for a desired application is proposed with careful consideration of the feasibility of monitoring certain analytes in sweat and interstitial fluid and the current development of the tools available to do so. Specifically, we focus on recent advancements in the engineering of biorecognition elements, the development of more robust signal transduction mechanisms, and novel integration schemes that allow for continuous quantitative analysis. Furthermore, we highlight the most compelling and promising prospects in the field of wearable biosensing and the challenges that remain in translating these technologies into useful products for disease management and for optimizing human performance.
Collapse
Affiliation(s)
- Zach Watkins
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA.
| | - Adam McHenry
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA
| | - Jason Heikenfeld
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA
| |
Collapse
|
6
|
Gurukandure A, Somasundaram S, Kurian ASN, Khuda N, Easley CJ. Building a Nucleic Acid Nanostructure with DNA-Epitope Conjugates for a Versatile Approach to Electrochemical Protein Detection. Anal Chem 2023; 95:18122-18129. [PMID: 38032341 PMCID: PMC10720615 DOI: 10.1021/acs.analchem.3c03512] [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] [Received: 08/06/2023] [Revised: 11/10/2023] [Accepted: 11/13/2023] [Indexed: 12/01/2023]
Abstract
The recent surge of effort in nucleic-acid-based electrochemical (EC) sensors has been fruitful, yet there remains a need for more generalizable EC platforms for sensing multiple classes of clinically relevant targets. We recently reported a nucleic acid nanostructure for simple, economical, and more generalizable EC readout of a range of analytes, including small molecules, peptides, proteins, and antibodies. The nanostructure is built through on-electrode enzymatic ligation of three oligonucleotides for attachment, binding, and signaling. However, the generalizable detection of larger proteins remains a challenge. Here, we adapted the sensor to quantify larger proteins in a more generic manner through conjugating the protein's minimized antibody-binding epitope to the central DNA strand. This concept was verified using creatine kinase (CK-MM), a biomarker of muscle damage and several disorders for which rapid clinical sensing is important. DNA-epitope conjugates permitted a competitive immunoassay for the CK protein at the electrode via square-wave voltammetry (SWV). Sensing through a signal-off mechanism, the anti-CK antibody limit of detection (LOD) was 5 nM with a response time as low as 3 min. Antibody displacement by native protein analytes gave a signal-on response with the CK sensing range from the LOD of 14 nM up to 100 nM, overlapping with the normal (nonelevated) human clinical range (3-37 nM), and the sensor was validated in 98% human serum. While a need for improved DNA-epitope conjugate purification was identified, overall, this approach allows the quantification of a generic protein- or peptide-binding antibody and should facilitate future quantitative EC readouts of clinically relevant proteins that were previously inaccessible to EC techniques.
Collapse
Affiliation(s)
- Asanka Gurukandure
- Department of Chemistry and
Biochemistry, Auburn University, Auburn, Alabama 36849, United States
| | - Subramaniam Somasundaram
- Department of Chemistry and
Biochemistry, Auburn University, Auburn, Alabama 36849, United States
| | - Amanda S. N. Kurian
- Department of Chemistry and
Biochemistry, Auburn University, Auburn, Alabama 36849, United States
| | - Niamat Khuda
- Department of Chemistry and
Biochemistry, Auburn University, Auburn, Alabama 36849, United States
| | - Christopher J. Easley
- Department of Chemistry and
Biochemistry, Auburn University, Auburn, Alabama 36849, United States
| |
Collapse
|
7
|
Pellitero M, Jensen IM, Dominique NL, Ekowo LC, Camden JP, Jenkins DM, Arroyo-Currás N. Stability of N-Heterocyclic Carbene Monolayers under Continuous Voltammetric Interrogation. ACS APPLIED MATERIALS & INTERFACES 2023; 15:35701-35709. [PMID: 37449918 PMCID: PMC10377464 DOI: 10.1021/acsami.3c06148] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 06/28/2023] [Indexed: 07/18/2023]
Abstract
N-Heterocyclic carbenes (NHCs) are promising monolayer-forming ligands that can overcome limitations of thiol-based monolayers in terms of stability, surface functionality, and reactivity across a variety of transition-metal surfaces. Recent publications have reported the ability of NHCs to support biomolecular receptors on gold substrates for sensing applications and improved tolerance to prolonged biofluid exposure relative to thiols. However, important questions remain regarding the stability of these monolayers when subjected to voltage perturbations, which is needed for applications with electrochemical platforms. Here, we investigate the ability of two NHCs, 1,3-diisopropylbenzimidazole and 5-(ethoxycarbonyl)-1,3-diisopropylbenzimidazole, to form monolayers via self-assembly from methanolic solutions of their trifluoromethanesulfonate salts. We compare the electrochemical behavior of the resulting monolayers relative to that of benchmark mercaptohexanol monolayers in phosphate-buffered saline. Within the -0.15 to 0.25 V vs Ag|AgCl voltage window, NHC monolayers are stable on gold surfaces, wherein they electrochemically perform like thiol-based monolayers and undergo similar reorganization kinetics, displaying long-term stability under incubation in buffered media and under continuous voltammetric interrogation. At negative voltages, NHC monolayers cathodically desorb from the electrode surface at lower bias (-0.1 V) than thiol-based monolayers (-0.5 V). At voltages more positive than 0.25 V, NHC monolayers anodically desorb from electrode surfaces at similar voltages to thiol-based monolayers. These results highlight new limitations to NHC monolayer stability imposed by electrochemical interrogation of the underlying gold electrodes. Our results serve as a framework for future optimization of NHC monolayers on gold for electrochemical applications, as well as structure-functionality studies of NHCs on gold.
Collapse
Affiliation(s)
- Miguel
Aller Pellitero
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Isabel M. Jensen
- Department
of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Nathaniel L. Dominique
- Department
of Chemistry and Biochemistry, University
of Notre Dame, Notre
Dame, Indiana 46556, United States
| | - Lilian Chinenye Ekowo
- Department
of Chemistry and Biochemistry, University
of Notre Dame, Notre
Dame, Indiana 46556, United States
| | - Jon P. Camden
- Department
of Chemistry and Biochemistry, University
of Notre Dame, Notre
Dame, Indiana 46556, United States
| | - David M. Jenkins
- Department
of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Netzahualcóyotl Arroyo-Currás
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| |
Collapse
|
8
|
Young T, Clark V, Arroyo-Currás N, Heikenfeld J. Perspective-The Feasibility of Continuous Protein Monitoring in Interstitial Fluid. ECS SENSORS PLUS 2023; 2:027001. [PMID: 37128505 PMCID: PMC10140668 DOI: 10.1149/2754-2726/accd7e] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/09/2023] [Indexed: 05/03/2023]
Abstract
Real-time continuous monitoring of proteins in-vivo holds great potential for personalized medical applications. Unfortunately, a prominent knowledge gap exists in the fundamental biology regarding protein transfer and correlation between interstitial fluid and blood. Additionally, technological sensing will require affinity-based platforms that cannot be robustly protected in-vivo and will therefore be challenged in sensitivity, longevity, and fouling over multi-day to week timelines. Here we use electrochemical aptamer sensors as a model system to discuss further research necessary to achieve continuous protein sensing.
Collapse
Affiliation(s)
- Thomas Young
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH 45221, United States of America
| | - Vincent Clark
- Chemistry-Biology Interface Program, Zanvyl Krieger School of Arts & Sciences, Johns Hopkins University, Baltimore, MD 21218, United States of America
| | - Netzahualcóyotl Arroyo-Currás
- Chemistry-Biology Interface Program, Zanvyl Krieger School of Arts & Sciences, Johns Hopkins University, Baltimore, MD 21218, United States of America
| | - Jason Heikenfeld
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH 45221, United States of America
- Department of Electrical & Computer Engineering, University of Cincinnati, Cincinnati, OH 45221, United States of America
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States of America
| |
Collapse
|
9
|
Pang Y, Ma Z, Song Q, Wang Z, Shi YE. Sensitive detection of butyrylcholinesterase activity based on a stimuli-responsive fluorescence reaction. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 299:122886. [PMID: 37210854 DOI: 10.1016/j.saa.2023.122886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 05/06/2023] [Accepted: 05/12/2023] [Indexed: 05/23/2023]
Abstract
A fluorogenic reaction between the chelate of Mn(II)-citric acid and terephthalic acid (PTA) was discovered, which was carried out through heating the aqueous mixture of Mn2+, citric acid and PTA. Detailed investigations indicated the reaction products were 2-hydroxyterephthalic acid (PTA-OH), which was attributed to the reaction between PTA and OH, formed by the triggering of Mn(II)-citric acid in the presence of dissolved O2. PTA-OH showed a strong blue fluorescence, peaked at 420 nm, and the fluorescence intensity presented a sensitive response to pH of the reaction system. Based on these mechanisms, the fluorogenic reaction was used for the detection of butyrylcholinesterase activity, achieving a detection limit of 0.15 U/L. The detection strategy was successfully applied in human serum samples, and it was also extended for the detection of organophosphorus pesticides and radical scavengers. Such a facile fluorogenic reaction and its stimuli-responsive properties offered an effective tool for designing detection pathways in the fields of clinical diagnosis, environmental monitoring and bioimaging.
Collapse
Affiliation(s)
- Yuexin Pang
- Key Laboratory of Chemical Biology of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Ministry of Education, College of Chemistry and Materials Science, Hebei University, Baoding 071002, China
| | - Zerui Ma
- Key Laboratory of Chemical Biology of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Ministry of Education, College of Chemistry and Materials Science, Hebei University, Baoding 071002, China
| | - Qian Song
- Key Laboratory of Chemical Biology of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Ministry of Education, College of Chemistry and Materials Science, Hebei University, Baoding 071002, China
| | - Zhenguang Wang
- Key Laboratory of Chemical Biology of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Ministry of Education, College of Chemistry and Materials Science, Hebei University, Baoding 071002, China.
| | - Yu-E Shi
- Key Laboratory of Chemical Biology of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Ministry of Education, College of Chemistry and Materials Science, Hebei University, Baoding 071002, China.
| |
Collapse
|
10
|
Shaver A, Arroyo-Currás N. Expanding the Monolayer Scope for Nucleic Acid-Based Electrochemical Sensors Beyond Thiols on Gold: Alkylphosphonic Acids on ITO. ECS SENSORS PLUS 2023; 2:010601. [PMID: 37006966 PMCID: PMC10053865 DOI: 10.1149/2754-2726/acc4d9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/15/2023] [Indexed: 03/18/2023]
Abstract
Electrochemical biosensors are a powerful and rapidly evolving molecular monitoring technology. Evidenced by the success of the continuous glucose monitor in managing Type 1 Diabetes, these sensors are capable of precise, accurate measurements in unprocessed biological environments. Nucleic acid-based electrochemical sensors (NBEs) are a specific type of biosensor that employs the target binding and conformational dynamics of nucleic acids for signal transduction. Currently, the vast majority of NBEs are fabricated via self-assembly of alkylthiols on Au electrodes. However, this architecture is limited in scope, as Au electrodes are not universally deployable for all potential NBE applications. Here, to expand the repertoire of materials on which NBEs can be made, we describe the multistep procedure for creating sensing monolayers of alkylphosphonic acids on a conductive oxide surface. Using such monolayers on indium tin oxide (ITO)-coated glass slides, we couple redox reporter-modified nucleic acids and demonstrate signaling of procaine-binding NBE sensors in buffer and human serum. We investigate the operational stability of these NBE sensors to reveal faster signal loss relative to benchmark thiol-on-gold sensing layers, a result that arises due to poor stability of the underlying ITO. Finally, we discuss future directions to continue expansion of NBE sensor materials and applications.
Collapse
Affiliation(s)
- Alexander Shaver
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21202, United States of America
| | - Netzahualcóyotl Arroyo-Currás
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21202, United States of America
- Department of Chemical and Biomolecular Engineering and Institute for NanoBioTechnology, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States of America
| |
Collapse
|