A photoelectrochemical sensing strategy based on single‐layer MoS2 modified electrode for methionine detection

Abstract

Graphical abstract Figure. No Caption available. HighlightsNanostructured MoS2 gives the biggest PEC signal onto carbon paste electrode.A decrement photoelectrochemical sensing strategy based on single‐layer nanoMoS2 modified electrode.Methionine, a amino acid, was found a good quencher.With LOD of 0.03 nM for Methionine. Abstract MoS2, a typical transition metal disulfide, is widely used in the photoelectrochemical (PEC) sensor construction. In general, MoS2 based PEC sensor are “signal‐on” strategies. Surprisingly, we discovered that the PEC response of MoS2 was quenched by methionine greatly. Based on this discovery, a reduction PEC sensing strategy utilized MoS2 modified electrode for methionine detection was fabricated for the first time. Experimental factors, such as, bias potential, volume of MoS2 and pH were studied. Under optimized conditions, the decreased intensity of the photocurrent signal was proportional to the logarithmic value of methionine concentrations from 0.1 nM to 1 &mgr;M with the detection limit of 0.03 nM. Moreover, this method exhibited good performance of excellent selectivity. And it showed potential applications in the practical determination of methionine in real‐life sample. This strategy not only expands the PEC detection method but also provides a simple, rapid response, good selectivity and high sensitivity way to detect methionine.