Chemically modified electrodes for recessed microelectrode array
Mohd Said, Nur Azura
Ogurtsov, Vladimir I.
Nagle, Lorraine C.
Chemical modifications on recessed microelectrode array, achieved via electrodeposition techniques are reported here. Silicon-based gold microelectrode arrays of 10Âµm microband and microdisc array were selected and functionalised using sol-gel and nanoporous gold (NPG) respectively. For electrochemically assisted self-assembly (EASA) formati6154on of sol-gel, electrode surface was first pre-treated with a self-assembled partial monolayer of mercaptopropyltrimethoxysilane (MPTMS) before transferring it into the sol containing cetyltrimethyl ammonium bromide (CTAB)/tetraethoxysilane (TEOS):MPTMS (90:10) precursors. A cathodic potential is then applied. It was found that larger current densities were required in ensuring successful film deposition when moving from macro- to micro- dimensions. For NPG modification, a chemical etching process called dealloying was employed. NPG of three different thicknesses have been successfully deposited. All the modified and functionalized microelectrode arrays were characterized by both optical (SEM) and electrochemical analysis (cyclic voltammetry and impedance spectroscopy). An increase in surface area and roughness has been observed and such will benefit for future sensing application.
Electrochemically assisted self-assembly , Mesoporous silica films , Nanoporous gold , Recessed microelectrode array , Electrochemical impedance spectroscopy
Mohd Said, N. A., Ogurtsov, V. I., Twomey, K., Nagle, L. C. and Herzog, G. (2016) 'Chemically modified electrodes for recessed microelectrode array', Procedia Chemistry, 20, pp. 12-24. DOI: 10.1016/j.proche.2016.07.002