Cargando…

A Microelectrode Array with Reproducible Performance Shows Loss of Consistency Following Functionalization with a Self-Assembled 6-Mercapto-1-hexanol Layer

For analytical applications involving label-free biosensors and multiple measurements, i.e., across an electrode array, it is essential to develop complete sensor systems capable of functionalization and of producing highly consistent responses. To achieve this, a multi-microelectrode device bearing...

Descripción completa

Detalles Bibliográficos
Autores principales: Corrigan, Damion K., Vezza, Vincent, Schulze, Holger, Bachmann, Till T., Mount, Andrew R., Walton, Anthony J., Terry, Jonathan G.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6022024/
https://www.ncbi.nlm.nih.gov/pubmed/29890722
http://dx.doi.org/10.3390/s18061891
_version_ 1783335587552428032
author Corrigan, Damion K.
Vezza, Vincent
Schulze, Holger
Bachmann, Till T.
Mount, Andrew R.
Walton, Anthony J.
Terry, Jonathan G.
author_facet Corrigan, Damion K.
Vezza, Vincent
Schulze, Holger
Bachmann, Till T.
Mount, Andrew R.
Walton, Anthony J.
Terry, Jonathan G.
author_sort Corrigan, Damion K.
collection PubMed
description For analytical applications involving label-free biosensors and multiple measurements, i.e., across an electrode array, it is essential to develop complete sensor systems capable of functionalization and of producing highly consistent responses. To achieve this, a multi-microelectrode device bearing twenty-four equivalent 50 µm diameter Pt disc microelectrodes was designed in an integrated 3-electrode system configuration and then fabricated. Cyclic voltammetry and electrochemical impedance spectroscopy were used for initial electrochemical characterization of the individual working electrodes. These confirmed the expected consistency of performance with a high degree of measurement reproducibility for each microelectrode across the array. With the aim of assessing the potential for production of an enhanced multi-electrode sensor for biomedical use, the working electrodes were then functionalized with 6-mercapto-1-hexanol (MCH). This is a well-known and commonly employed surface modification process, which involves the same principles of thiol attachment chemistry and self-assembled monolayer (SAM) formation commonly employed in the functionalization of electrodes and the formation of biosensors. Following this SAM formation, the reproducibility of the observed electrochemical signal between electrodes was seen to decrease markedly, compromising the ability to achieve consistent analytical measurements from the sensor array following this relatively simple and well-established surface modification. To successfully and consistently functionalize the sensors, it was necessary to dilute the constituent molecules by a factor of ten thousand to support adequate SAM formation on microelectrodes. The use of this multi-electrode device therefore demonstrates in a high throughput manner irreproducibility in the SAM formation process at the higher concentration, even though these electrodes are apparently functionalized simultaneously in the same film formation environment, confirming that the often seen significant electrode-to-electrode variation in label-free SAM biosensing films formed under such conditions is not likely to be due to variation in film deposition conditions, but rather kinetically controlled variation in the SAM layer formation process at these microelectrodes.
format Online
Article
Text
id pubmed-6022024
institution National Center for Biotechnology Information
language English
publishDate 2018
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-60220242018-07-02 A Microelectrode Array with Reproducible Performance Shows Loss of Consistency Following Functionalization with a Self-Assembled 6-Mercapto-1-hexanol Layer Corrigan, Damion K. Vezza, Vincent Schulze, Holger Bachmann, Till T. Mount, Andrew R. Walton, Anthony J. Terry, Jonathan G. Sensors (Basel) Article For analytical applications involving label-free biosensors and multiple measurements, i.e., across an electrode array, it is essential to develop complete sensor systems capable of functionalization and of producing highly consistent responses. To achieve this, a multi-microelectrode device bearing twenty-four equivalent 50 µm diameter Pt disc microelectrodes was designed in an integrated 3-electrode system configuration and then fabricated. Cyclic voltammetry and electrochemical impedance spectroscopy were used for initial electrochemical characterization of the individual working electrodes. These confirmed the expected consistency of performance with a high degree of measurement reproducibility for each microelectrode across the array. With the aim of assessing the potential for production of an enhanced multi-electrode sensor for biomedical use, the working electrodes were then functionalized with 6-mercapto-1-hexanol (MCH). This is a well-known and commonly employed surface modification process, which involves the same principles of thiol attachment chemistry and self-assembled monolayer (SAM) formation commonly employed in the functionalization of electrodes and the formation of biosensors. Following this SAM formation, the reproducibility of the observed electrochemical signal between electrodes was seen to decrease markedly, compromising the ability to achieve consistent analytical measurements from the sensor array following this relatively simple and well-established surface modification. To successfully and consistently functionalize the sensors, it was necessary to dilute the constituent molecules by a factor of ten thousand to support adequate SAM formation on microelectrodes. The use of this multi-electrode device therefore demonstrates in a high throughput manner irreproducibility in the SAM formation process at the higher concentration, even though these electrodes are apparently functionalized simultaneously in the same film formation environment, confirming that the often seen significant electrode-to-electrode variation in label-free SAM biosensing films formed under such conditions is not likely to be due to variation in film deposition conditions, but rather kinetically controlled variation in the SAM layer formation process at these microelectrodes. MDPI 2018-06-09 /pmc/articles/PMC6022024/ /pubmed/29890722 http://dx.doi.org/10.3390/s18061891 Text en © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Corrigan, Damion K.
Vezza, Vincent
Schulze, Holger
Bachmann, Till T.
Mount, Andrew R.
Walton, Anthony J.
Terry, Jonathan G.
A Microelectrode Array with Reproducible Performance Shows Loss of Consistency Following Functionalization with a Self-Assembled 6-Mercapto-1-hexanol Layer
title A Microelectrode Array with Reproducible Performance Shows Loss of Consistency Following Functionalization with a Self-Assembled 6-Mercapto-1-hexanol Layer
title_full A Microelectrode Array with Reproducible Performance Shows Loss of Consistency Following Functionalization with a Self-Assembled 6-Mercapto-1-hexanol Layer
title_fullStr A Microelectrode Array with Reproducible Performance Shows Loss of Consistency Following Functionalization with a Self-Assembled 6-Mercapto-1-hexanol Layer
title_full_unstemmed A Microelectrode Array with Reproducible Performance Shows Loss of Consistency Following Functionalization with a Self-Assembled 6-Mercapto-1-hexanol Layer
title_short A Microelectrode Array with Reproducible Performance Shows Loss of Consistency Following Functionalization with a Self-Assembled 6-Mercapto-1-hexanol Layer
title_sort microelectrode array with reproducible performance shows loss of consistency following functionalization with a self-assembled 6-mercapto-1-hexanol layer
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6022024/
https://www.ncbi.nlm.nih.gov/pubmed/29890722
http://dx.doi.org/10.3390/s18061891
work_keys_str_mv AT corrigandamionk amicroelectrodearraywithreproducibleperformanceshowslossofconsistencyfollowingfunctionalizationwithaselfassembled6mercapto1hexanollayer
AT vezzavincent amicroelectrodearraywithreproducibleperformanceshowslossofconsistencyfollowingfunctionalizationwithaselfassembled6mercapto1hexanollayer
AT schulzeholger amicroelectrodearraywithreproducibleperformanceshowslossofconsistencyfollowingfunctionalizationwithaselfassembled6mercapto1hexanollayer
AT bachmanntillt amicroelectrodearraywithreproducibleperformanceshowslossofconsistencyfollowingfunctionalizationwithaselfassembled6mercapto1hexanollayer
AT mountandrewr amicroelectrodearraywithreproducibleperformanceshowslossofconsistencyfollowingfunctionalizationwithaselfassembled6mercapto1hexanollayer
AT waltonanthonyj amicroelectrodearraywithreproducibleperformanceshowslossofconsistencyfollowingfunctionalizationwithaselfassembled6mercapto1hexanollayer
AT terryjonathang amicroelectrodearraywithreproducibleperformanceshowslossofconsistencyfollowingfunctionalizationwithaselfassembled6mercapto1hexanollayer
AT corrigandamionk microelectrodearraywithreproducibleperformanceshowslossofconsistencyfollowingfunctionalizationwithaselfassembled6mercapto1hexanollayer
AT vezzavincent microelectrodearraywithreproducibleperformanceshowslossofconsistencyfollowingfunctionalizationwithaselfassembled6mercapto1hexanollayer
AT schulzeholger microelectrodearraywithreproducibleperformanceshowslossofconsistencyfollowingfunctionalizationwithaselfassembled6mercapto1hexanollayer
AT bachmanntillt microelectrodearraywithreproducibleperformanceshowslossofconsistencyfollowingfunctionalizationwithaselfassembled6mercapto1hexanollayer
AT mountandrewr microelectrodearraywithreproducibleperformanceshowslossofconsistencyfollowingfunctionalizationwithaselfassembled6mercapto1hexanollayer
AT waltonanthonyj microelectrodearraywithreproducibleperformanceshowslossofconsistencyfollowingfunctionalizationwithaselfassembled6mercapto1hexanollayer
AT terryjonathang microelectrodearraywithreproducibleperformanceshowslossofconsistencyfollowingfunctionalizationwithaselfassembled6mercapto1hexanollayer