Analytical Chemistry

Light-Addressable Electrochemical Sensing of Dopamine Using on N-Silicon/gold Schottky Junctions

Glen O'Neil Montclair State University

Abstract

Here, we report the use of semiconductor/metal (Schottky) junctions as light-addressable electrochemical sensors (LAES). We employ an n-Si/Au Schottky junction prepared by electrodeposition of Au nanoparticles (NPs) on a freshly etched n-Si photoelectrode. The sensors demonstrate near reversible electrochemical behavior for the oxidation of ferrocene methanol and potassium ferrocyanide. Moreover, n-Si/Au LAES were stable for 1000 cyclic voltammetry cycles in an aqueous electrolyte – even though the n-Si surface was only partially covered with Au NPs. We also challenged the LAES to detect the neurotransmitter dopamine and found that the sensors were quantitative over the range from 15-500 µM in buffer. We used local illumination to generate a virtual array of electrochemical sensors for dopamine as a strategy for circumventing sensor fouling.

Content

Thumbnail image of light adressable sensing_ms_final.pdf
download asset light adressable sensing_ms_final.pdf 1 MB [opens in a new tab]

Supplementary material

Thumbnail image of light adressable sensing_esi_final.pdf
download asset light adressable sensing_esi_final.pdf 3 MB [opens in a new tab]
light adressable sensing esi final