A photoelectrochemical sensor for ultrasensitive dopamine detection based on single-layer NanoMoS2 modified gold electrode

Photoactive material is a crucial factor which affects the sensitivity and selectivity of the photoelectro-chemical (PEC) sensor. A simple PEC sensing platform was fabricated using nanoMoS(2) modified gold electrode (nanoMoS(2)/GE) in this paper. Three kinds of nanoMoS(2), single-layer nanoMoS(2), multiple layers nanoMoS(2) and small-sized nanoMoS(2), were used to modify the electrode. It was found that the single-layer nanoMoS(2) showed utmost PEC response. The photocurrent of nanoMoS(2)/GE was drastically improved upon the addition of dopamine, which was attributed to the life improvement of the electron-hole pairs. Based on the enhanced photocurrent signal, a PEC methodology for ultrasensitive determination of dopamine has been developed, which showed linearly enhanced photocurrent by increasing the dopamine concentration from 1.0 x 10(-11) M to 1.0 x 10(-5) M with a detection limit of 2.3 x 10(-12) M and the RSD was 3.9% at 2.0 x 10(-10) M (n=9) under optimal conditions. This method showed high sensitivity, simplicity and wide linearity range which opened up a new promising signal-on PEC platform for small molecule detection in bioanalysis. (C) 2017 Elsevier B.V. All rights reserved.