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 photoelectrochemical (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 × 10 −11 M to 1.0 × 10 −5 M with a detection limit of 2.3 × 10 −12 M and the RSD was 3.9% at 2.0 × 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. [ABSTRACT FROM AUTHOR]