▎ 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 mu A mM(-1) and a detection limit of 11.4 x 10(-7) M L-1. A linear calibration graph was constructed in the ranging 3.90 x 10(-6) to 3.19 x 10(-5) M L-1. The method was successfully applied for the determination of Sudan I in red chili powder samples. (C) 2014 Elsevier Ltd. All rights reserved.