A signal “switch-on” photoelectrochemical sensor based on a 3D-FM/BiOI heterostructure for the sensitive detection of l-ascorbic acid

Abstract

A highly efficient 3D flower MoS₂ (3D-FM)-based heterostructure photocatalyst (3D-FM/BiOI) was successfully obtained via a simple hydrothermal synthesis strategy. 3D-FM/BiOI showed prominent photoelectrochemical performance, distinguished stability and good selectivity. The introduction of 3D-FM, by promoting the photoelectric property attributed to it, facilitated the separation of photogenerated electron–hole pairs. Since the redox process of L-ascorbic acid (L-AA) resulted in an increasing photocurrent of 3D-FM/BiOI, a signal “switch-on” photoelectrochemical sensor (PECS) was designed to sensitively determine L-AA for the first time. Under optimized conditions, the 3D-FM/BiOI PECS worked over a wide range from 1 μM to 0.8 mM with a low detection limit of 0.05 μM (S/N = 3). The PECS was successfully exploited for L-AA sensing in human urine with excellent accuracy and applicability, demonstrating its practical precision and superb serviceability. Furthermore, the 3D-FM/BiOI PECS exhibited satisfactory selectivity and stability, providing a great potential platform for the construction of an L-AA sensor in various practical samples and complicated environments.