A ZnS–SnS2/S–rGO ternary heterostructure for electrochemical detection of azo toxic dye sunset yellow in food samples

Abstract

High consumption of azo dyes such as sunset yellow (SY), widely used to improve the color and taste of some food products, is harmful and leads to diseases and problems in humans. Therefore, one of the important missions of scientists and researchers is to invent a fast and low-cost method to detect the amount of SY in food products. Here, we synthesized ZnS–SnS₂/S–rGO and modified a carbon paste electrode to design a sensor for SY determination in an aqueous environment and some real food samples. The morphology and structure of the ZnS–SnS₂/S–rGO were investigated by FE-SEM, HR-TEM, XPS, EDS, ATR-IR, Raman, and XRD techniques. Differentiated pulse voltammetry (DPV), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) methods were used to study the electrochemical section. The designed sensor had a detection limit of 140 nM (S/N = 3) and a wide linear range of 3–100 μM and was used for SY determination in some real food samples with excellent recoveries (between 95.09 and 108.28%). This sensor has a high sensitivity and selectivity compared to the analog molecules with a similar structure for SY. It has commendable stability and satisfactory reproducibility.