Amperometric detection of Sudan Ⅰ in red chili powder samples using Ag nanoparticles decorated graphene oxide modified glassy carbon electrode

摘要

A simple and sensitive electrochemical method was developed to determine the concentration of Sudan Ⅰ in chili powder based on silver nanoparticles decorated graphene oxide modified glassy carbon electrode (AgNPs@GO/GCE). The voltammetry behaviour of Sudan Ⅰ on modified GCE was investigated in phosphate buffer medium (PBS) with various pH ranges and the electron transfer properties were studied. It is found that the AgNPs@GO/GCE can catalyse the reduction of azo group, -N=N- followed by electrochemical oxidation of ~-OH group present in Sudan Ⅰ dye molecule. Quantitative detection of Sudan Ⅰ present in food products was carried out by amperometry method in which reduction potential was fixed at -0.77 V vs. Ag/AgCl. The amperometry method showed an excellent performance with a sensitivity of 6.83 μA mM~(-1) and a detection limit of 11.4 × 10~(-7) M L_(-1) A linear calibration graph was constructed in the ranging 3.90 × 10~(-6) to 3.19 × 10~(-5) M L~(-1). The method was successfully applied for the determination of Sudan Ⅰ in red chili powder samples.