1
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Uçar A, González-Fernández E, Staderini M, Murray AF, Mount AR, Bradley M. pH-Activated Dissolvable Polymeric Coatings to Reduce Biofouling on Electrochemical Sensors. J Funct Biomater 2023; 14:329. [PMID: 37367293 DOI: 10.3390/jfb14060329] [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: 05/10/2023] [Revised: 06/14/2023] [Accepted: 06/16/2023] [Indexed: 06/28/2023] Open
Abstract
Implantable electrochemical sensors that enable the real-time detection of significant biomarkers offer huge potential for the enhancement and personalisation of therapies; however, biofouling is a key challenge encountered by any implantable system. This is particularly an issue immediately after implantation, when the foreign body response and associated biofouling processes are at their most active in passivating a foreign object. Here, we present the development of a sensor protection and activation strategy against biofouling, based on coatings consisting of a pH-triggered, dissolvable polymer, that covered a functionalised electrode surface. We demonstrate that reproducible delayed sensor activation can be achieved, and that the length of this delay can be controlled by the optimisation of coating thickness, homogeneity and density through tuning of the coating method and temperature. Comparative evaluation of the polymer-coated and uncoated probe-modified electrodes in biological media revealed significant improvements in their anti-biofouling characteristics, demonstrating that this offers a promising approach to the design of enhanced sensing devices.
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Affiliation(s)
- Ahmet Uçar
- School of Engineering, Institute for Bioengineering, The University of Edinburgh, The King's Buildings, Mayfield Road, Edinburgh EH9 3JL, UK
- Department of Energy Systems Engineering, Faculty of Engineering and Natural Sciences, Ankara Yıldırım Beyazıt University, 06010 Ankara, Turkey
| | - Eva González-Fernández
- School of Chemistry, University of Edinburgh, Joseph Black Building, West Mains Road, Edinburgh EH9 3FJ, UK
| | - Matteo Staderini
- School of Chemistry, University of Edinburgh, Joseph Black Building, West Mains Road, Edinburgh EH9 3FJ, UK
| | - Alan F Murray
- School of Engineering, Institute for Bioengineering, The University of Edinburgh, The King's Buildings, Mayfield Road, Edinburgh EH9 3JL, UK
| | - Andrew R Mount
- School of Chemistry, University of Edinburgh, Joseph Black Building, West Mains Road, Edinburgh EH9 3FJ, UK
| | - Mark Bradley
- School of Chemistry, University of Edinburgh, Joseph Black Building, West Mains Road, Edinburgh EH9 3FJ, UK
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2
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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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3
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An Amine-Reactive Phenazine Ethosulfate (arPES)-A Novel Redox Probe for Electrochemical Aptamer-Based Sensor. SENSORS 2022; 22:s22051760. [PMID: 35270906 PMCID: PMC8914840 DOI: 10.3390/s22051760] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 02/20/2022] [Accepted: 02/21/2022] [Indexed: 11/29/2022]
Abstract
Electrochemical aptamer-based biosensors (E-ABs) are attractive candidates for use in biomarker detection systems due to their sensitivity, rapid response, and design flexibility. There are only several redox probes that were employed previously for this application, and a combination of redox probes affords some advantages in target detection. Thus, it would be advantageous to study new redox probes in an E-AB system. In this study, we report the use of amine-reactive phenazine ethosulfate (arPES) for E-AB through its conjugation to the terminus of thrombin-binding aptamer. The constructed E-AB can detect thrombin by square-wave voltammetry (SWV), showing peak current at −0.15 V vs. Ag/AgCl at pH 7, which differs from redox probes used previously for E-ABs. We also compared the characteristics of PES as a redox probe for E-AB to methylene blue (MB), which is widely used. arPES showed stable signal at physiological pH. Moreover, the pH profile of arPES modified thrombin-binding aptamer revealed the potential application of arPES for a simultaneous multianalyte detection system. This could be achieved using different aptamers with several redox probes in tandem that harbor various electrochemical peak potentials. Our findings present a great opportunity to improve the current standard of biological fluid monitoring using E-AB.
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4
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Suthar J, Prieto-Simon B, Williams GR, Guldin S. Dual-Mode and Label-Free Detection of Exosomes from Plasma Using an Electrochemical Quartz Crystal Microbalance with Dissipation Monitoring. Anal Chem 2022. [PMID: 35072456 DOI: 10.1021/acs.analchem.1c04282/suppl_file/ac1c04282_si_001.pdf] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The biomolecular contents of extracellular vesicles, such as exosomes, have been shown to be crucial in intercellular communication and disease propagation. As a result, there has been a recent surge in the exploration of novel biosensing platforms that can sensitively and specifically detect exosomal content such as proteins and nucleic acids, with a view toward application in diagnostic assays. Here, we demonstrate dual-mode and label-free detection of plasma exosomes using an electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D). The platform adopts a direct immunosensing approach to effectively capture exosomes via their surface protein expression of CD63. By combining QCM-D with a tandem in situ electrochemical impedance spectroscopy measurement, we are able to demonstrate relationships between mass, viscoelasticity and impedance inducing properties of each functional layer and analyte. In addition to lowering the limit of detection (by a factor of 2-4) to 6.71 × 107 exosome-sized particles (ESP) per mL in 25% v/v serum, the synergy between dissipation and impedance response introduces improved sensing specificity by offering further distinction between soft and rigid analytes, thereby promoting EQCM-D as an important technique for exosome analysis.
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Affiliation(s)
- Jugal Suthar
- UCL School of Pharmacy, University College London, 29-39 Brunswick Square, Bloomsbury, London, WC1N 1AX, United Kingdom
- Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, United Kingdom
| | - Beatriz Prieto-Simon
- Department of Electronic Engineering, Universitat Rovira i Virgili, 43007, Tarragona, Spain
- ICREA, Pg. Lluis Companys 23, 08010, Barcelona, Spain
| | - Gareth R Williams
- UCL School of Pharmacy, University College London, 29-39 Brunswick Square, Bloomsbury, London, WC1N 1AX, United Kingdom
| | - Stefan Guldin
- Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, United Kingdom
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5
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González-Fernández E, Staderini M, Marland JRK, Gray ME, Uçar A, Dunare C, Blair EO, Sullivan P, Tsiamis A, Greenhalgh SN, Gregson R, Clutton RE, Smith S, Terry JG, Argyle DJ, Walton AJ, Mount AR, Bradley M, Murray AF. In vivo application of an implantable tri-anchored methylene blue-based electrochemical pH sensor. Biosens Bioelectron 2022; 197:113728. [PMID: 34763151 DOI: 10.1016/j.bios.2021.113728] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 10/06/2021] [Accepted: 10/21/2021] [Indexed: 12/13/2022]
Abstract
The development of robust implantable sensors is important in the successful advancement of personalised medicine as they have the potential to provide in situ real-time data regarding the status of health and disease and the effectiveness of treatment. Tissue pH is a key physiological parameter and herein, we report the design, fabrication, functionalisation, encapsulation and protection of a miniaturised, self-contained, electrochemical pH sensor system and characterisation of sensor performance. Notably for the first time in this environment the pH sensor was based on a methylene blue redox reporter which showed remarkable robustness, accuracy and sensitivity. This was achieved by encapsulation of a self-assembled monolayer containing methylene blue entrapped within a Nafion layer. Another powerful feature was the incorporation, within the same implanted device, of a fabricated on-chip Ag/AgCl reference electrode - vital in any electrochemical sensor, but often ignored. When utilised in vivo, the sensor allowed accurate tracking of externally induced pH changes within a naturally occurring ovine lung cancer model, and correlated well with single point laboratory measurements made on extracted arterial blood, whilst enabling in vivo time-dependent measurements. The sensors functioned robustly whilst implanted, and maintained in vitro function once extracted and together, these results demonstrate proof-of-concept of the ability to sense real-time intratumoral tissue pH changes in vivo.
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Affiliation(s)
- Eva González-Fernández
- EaStCHEM, School of Chemistry, University of Edinburgh, Joseph Black Building, West Mains Road, Edinburgh, EH9 3FJ, UK
| | - Matteo Staderini
- EaStCHEM, School of Chemistry, University of Edinburgh, Joseph Black Building, West Mains Road, Edinburgh, EH9 3FJ, UK
| | - Jamie R K Marland
- School of Engineering, Institute for Integrated Micro and Nano Systems, University of Edinburgh, Scottish Microelectronics Centre, The King's Buildings, Edinburgh, EH9 3FF, UK
| | - Mark E Gray
- The Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush, Roslin, Midlothian, EH25 9RG, UK
| | - Ahmet Uçar
- EaStCHEM, School of Chemistry, University of Edinburgh, Joseph Black Building, West Mains Road, Edinburgh, EH9 3FJ, UK; School of Engineering, Institute for Bioengineering, University of Edinburgh, Faraday Building, The King's Buildings, Edinburgh, EH9 3DW, UK; Department of Biomedical Engineering, Faculty of Engineering and Natural Sciences, Ankara Yildirim Beyazıt University, 06010 Ankara, Turkey
| | - Camelia Dunare
- School of Engineering, Institute for Integrated Micro and Nano Systems, University of Edinburgh, Scottish Microelectronics Centre, The King's Buildings, Edinburgh, EH9 3FF, UK
| | - Ewen O Blair
- School of Engineering, Institute for Integrated Micro and Nano Systems, University of Edinburgh, Scottish Microelectronics Centre, The King's Buildings, Edinburgh, EH9 3FF, UK
| | - Paul Sullivan
- School of Engineering, Institute for Bioengineering, University of Edinburgh, Faraday Building, The King's Buildings, Edinburgh, EH9 3DW, UK
| | - Andreas Tsiamis
- School of Engineering, Institute for Bioengineering, University of Edinburgh, Faraday Building, The King's Buildings, Edinburgh, EH9 3DW, UK
| | - Stephen N Greenhalgh
- The Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush, Roslin, Midlothian, EH25 9RG, UK
| | - Rachael Gregson
- The Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush, Roslin, Midlothian, EH25 9RG, UK
| | - Richard Eddie Clutton
- The Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush, Roslin, Midlothian, EH25 9RG, UK
| | - Stewart Smith
- School of Engineering, Institute for Bioengineering, University of Edinburgh, Faraday Building, The King's Buildings, Edinburgh, EH9 3DW, UK
| | - Jonathan G Terry
- School of Engineering, Institute for Integrated Micro and Nano Systems, University of Edinburgh, Scottish Microelectronics Centre, The King's Buildings, Edinburgh, EH9 3FF, UK
| | - David J Argyle
- The Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush, Roslin, Midlothian, EH25 9RG, UK
| | - Anthony J Walton
- School of Engineering, Institute for Integrated Micro and Nano Systems, University of Edinburgh, Scottish Microelectronics Centre, The King's Buildings, Edinburgh, EH9 3FF, UK
| | - Andrew R Mount
- EaStCHEM, School of Chemistry, University of Edinburgh, Joseph Black Building, West Mains Road, Edinburgh, EH9 3FJ, UK.
| | - Mark Bradley
- EaStCHEM, School of Chemistry, University of Edinburgh, Joseph Black Building, West Mains Road, Edinburgh, EH9 3FJ, UK.
| | - Alan F Murray
- School of Engineering, Institute for Bioengineering, University of Edinburgh, Faraday Building, The King's Buildings, Edinburgh, EH9 3DW, UK.
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6
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Suthar J, Prieto-Simon B, Williams GR, Guldin S. Dual-Mode and Label-Free Detection of Exosomes from Plasma Using an Electrochemical Quartz Crystal Microbalance with Dissipation Monitoring. Anal Chem 2022; 94:2465-2475. [PMID: 35072456 PMCID: PMC9096790 DOI: 10.1021/acs.analchem.1c04282] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
![]()
The
biomolecular contents of extracellular vesicles, such as exosomes,
have been shown to be crucial in intercellular communication and disease
propagation. As a result, there has been a recent surge in the exploration
of novel biosensing platforms that can sensitively and specifically
detect exosomal content such as proteins and nucleic acids, with a
view toward application in diagnostic assays. Here, we demonstrate
dual-mode and label-free detection of plasma exosomes using an electrochemical
quartz crystal microbalance with dissipation monitoring (EQCM-D).
The platform adopts a direct immunosensing approach to effectively
capture exosomes via their surface protein expression of CD63. By
combining QCM-D with a tandem in situ electrochemical impedance spectroscopy
measurement, we are able to demonstrate relationships between mass,
viscoelasticity and impedance inducing properties of each functional
layer and analyte. In addition to lowering the limit of detection
(by a factor of 2–4) to 6.71 × 107 exosome-sized
particles (ESP) per mL in 25% v/v serum, the synergy between dissipation
and impedance response introduces improved sensing specificity by
offering further distinction between soft and rigid analytes, thereby
promoting EQCM-D as an important technique for exosome analysis.
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Affiliation(s)
- Jugal Suthar
- UCL School of Pharmacy, University College London, 29-39 Brunswick Square, Bloomsbury, London, WC1N 1AX, United Kingdom
- Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, United Kingdom
| | - Beatriz Prieto-Simon
- Department of Electronic Engineering, Universitat Rovira i Virgili, 43007, Tarragona, Spain
- ICREA, Pg. Lluis Companys 23, 08010, Barcelona, Spain
| | - Gareth R. Williams
- UCL School of Pharmacy, University College London, 29-39 Brunswick Square, Bloomsbury, London, WC1N 1AX, United Kingdom
| | - Stefan Guldin
- Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, United Kingdom
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7
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Singh N, Chung S, Sveiven M, Hall DA. Cortisol Detection in Undiluted Human Serum Using a Sensitive Electrochemical Structure-Switching Aptamer over an Antifouling Nanocomposite Layer. ACS OMEGA 2021; 6:27888-27897. [PMID: 34722988 PMCID: PMC8552316 DOI: 10.1021/acsomega.1c03552] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/16/2021] [Indexed: 05/16/2023]
Abstract
There is a strong and growing need to monitor stress biomarkers in vivo for real-time emotional and wellness assessment. Toward this, we report a reagent-free electrochemical aptasensor with a nanocomposite antifouling layer for sensitive and continuous detection of cortisol in human serum. A thiolated, methylene blue (MB)-tagged conformation-switching aptamer was immobilized over a gold nanowire (AuNW) nanocomposite to capture cortisol and generate a signal proportional to the cortisol concentration. The signal is recorded through differential pulse voltammetry (DPV) and chronoamperometry. The aptasensor exhibited a sensitive response with 0.51 and 0.68 nM detection limits in spiked buffer and undiluted serum samples, respectively. Interference from other structurally similar analogs, namely, epinephrine and cholic acid, was negligible (<10%). The developed nanocomposite-based aptasensor showed excellent stability in undiluted human serum, outperforming several other nanocomposite materials even after prolonged exposure. This work lays the foundation for new biosensor formats such as implantable and wearable sensors.
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Affiliation(s)
- Naveen
K. Singh
- Department
of Electrical and Computer Engineering, University of California—San Diego, La Jolla, California 92093, United States
| | - Saeromi Chung
- Department
of Electrical and Computer Engineering, University of California—San Diego, La Jolla, California 92093, United States
| | - Michael Sveiven
- Department
of Bioengineering, University of California—San
Diego, La Jolla, California 92093, United States
| | - Drew A. Hall
- Department
of Electrical and Computer Engineering, University of California—San Diego, La Jolla, California 92093, United States
- Department
of Bioengineering, University of California—San
Diego, La Jolla, California 92093, United States
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8
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Mokhtari Z, Khajehsharifi H, Hashemnia S, Shahrokhian S. Predicting the Cardiac Troponin I (cTnl) Aptamer/Methylene Blue Configuration Using Computational Modeling Studies: A Screening Search Method for Constructing Aptasensors. ChemistrySelect 2020. [DOI: 10.1002/slct.202001780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Zaynab Mokhtari
- Department of Chemistry Yasouj University, Under Hill Yasouj 75918-74934 Iran
| | | | - Sedigheh Hashemnia
- Department of Chemistry, Faculty of Sciences Persian Gulf University Bushehr 75169 Iran
| | - Saeed Shahrokhian
- Department of Chemistry Sharif University of Technology Tehran 11155-9516 Iran
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9
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Veselinovic J, Almashtoub S, Seker E. Anomalous Trends in Nucleic Acid-Based Electrochemical Biosensors with Nanoporous Gold Electrodes. Anal Chem 2019; 91:11923-11931. [PMID: 31429540 DOI: 10.1021/acs.analchem.9b02686] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Molecular diagnostics have significantly advanced the early detection of diseases, where electrochemical sensing of biomarkers has shown considerable promise. For a nucleic acid-based electrochemical sensor with signal-off behavior, the performance is evaluated by percent signal suppression (% ss), which indicates the change in current after hybridization. The % ss is generally due to more redox molecules (e.g., methylene blue) associating with the probe DNA bases in the single-strand form than the double-strand form upon hybridization with the target nucleic acid. Nanostructured electrodes generally enhance electrochemical sensor performance via several mechanisms, including increased number of capture probes per electrode volume and unique nanoscale transport phenomena. Here, we employ nanoporous gold (np-Au) as a model electrode material to study the influence of probe immobilization solution concentration on sensor performance and the underlying mechanisms. Unlike planar gold (pl-Au) electrodes, where % ss reaches a steady state with increasing concentration of the grafting solution, the % ss displays peak performance at certain grafting solution concentrations followed by rapid deterioration and reversal of the % ss polarity, suggesting an unexpected case of increased charge transfer upon hybridization. Fluorometric assessments of electrochemically desorbed nucleic acids for different electrode morphologies reveal that a significant amount of DNA molecules (unhybridized and hybridized) remain within the nanopores posthybridization. Analysis of electrochemical signals (e.g., square wave voltammogram shape) suggests that the large unbound nucleic acid concentration may be altering the modes of methylene blue interaction with the nucleic acids and charge transfer to the electrode surfaces.
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Affiliation(s)
- Jovana Veselinovic
- Department of Chemical Engineering , University of California, Davis , Davis , California 95616 , United States
| | - Suzan Almashtoub
- Department of Chemical Engineering , University of California, Davis , Davis , California 95616 , United States
| | - Erkin Seker
- Department of Electrical and Computer Engineering , University of California, Davis , Davis , California 95616 , United States
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10
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Ntola CN, Kataky R. ‘Soft’ electroactive particles and their interaction with lipid membranes. Electrochem commun 2017. [DOI: 10.1016/j.elecom.2017.02.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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11
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Koutsoumpeli E, Tiede C, Murray J, Tang A, Bon RS, Tomlinson DC, Johnson S. Antibody Mimetics for the Detection of Small Organic Compounds Using a Quartz Crystal Microbalance. Anal Chem 2017; 89:3051-3058. [PMID: 28192970 DOI: 10.1021/acs.analchem.6b04790] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Conventional immunoassays rely on antibodies that provide high affinity, specificity, and selectivity against a target analyte. However, the use of antibodies for the detection of small-sized, nonimmunogenic targets, such as pharmaceuticals and environmental contaminants, presents a number of challenges. Recent advances in protein engineering have led to the emergence of antibody mimetics that offer the high affinity and specificity associated with antibodies, but with reduced batch-to-batch variability, high stability, and in vitro selection to ensure rapid discovery of binders against a wide range of targets. In this work we explore the potential of Affimers, a recent example of antibody mimetics, as suitable bioreceptors for the detection of small organic target compounds, here methylene blue. Target immobilization for Affimer characterization was achieved using long-chained alkanethiol linkers coupled with oligoethylene glycol (LCAT-OEG). Using quartz crystal microbalance with dissipation monitoring (QCM-D), we determine the affinity constant, KD, of the methylene blue Affimer to be comparable to that of antibodies. Further, we demonstrate the high selectivity of Affimers for its target in complex matrixes, here a limnetic sample. Finally, we demonstrate an Affimer-based competition assay, illustrating the potential of Affimers as bioreceptors in immunoassays for the detection of small-sized, nonimmunogenic compounds.
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Affiliation(s)
- Eleni Koutsoumpeli
- Department of Electronics, University of York , Heslington, York, YO10 5DD, United Kingdom
| | | | | | | | | | | | - Steven Johnson
- Department of Electronics, University of York , Heslington, York, YO10 5DD, United Kingdom
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