Bisphenol A electrochemiluminescence sensor based on reduced graphene oxide-Bi2ZnS4 nanocomposite

Abstract

In this study, reduced graphene oxide-bismuth zinc sulfide nanocomposite (RGO-Bi2ZnS4) with excellent electrochemiluminescence (ECL) signal amplification were prepared by a solvothermal method and successfully used to fabricate ECL sensors to rapidly detect bisphenol A (BPA). Bi2ZnS4 can form numerous nanosheet clusters uniformly distributed on the surface of a graphene sheet, which not only avoids the phenomenon of stacking of the graphene layers due to π-π interactions, but also greatly increases the specific surface area of graphene, thus providing a wider active area and channel for the oxidation-reduction reaction on the electrode. Chitosan as a kind of immobilized adhesive, with good adhesion and good compatibility, can greatly facilitate the stabilization of Ru(bpy)32+ and RGO-Bi2ZnS4 nanocomposites on the surface of the electrode and the smooth fabrication of the subsequent sensors. Also, the electron transfer process in this system is described in detail based on the effective quenching effect of BPA on Ru(bpy)32+/tripropylamine system. At the same time, the ECL amplification performance of RGO-Bi2ZnS4 nanocomposite in the analysis and testing was evaluated by measuring the BPA concentration in actual water samples. Under optimal conditions, the fabricated ECL sensor has good sensitivity to BPA, with a linear range of 0.05–3.0 μM and a detection limit of 0.02 μM. In this study, a convenient and promising solution for the rapid detection of BPA or its environmental hormones is provided, and is also anticipated to be a reference for the analysis of other biochemical compounds.