▎ 摘　　要

A new and sensitive electrochemical sensor for simultaneous determination of sunset yellow and tartrazine was constructed by poly (diallyldimethylammonium chloride) (PDDA)-dispersed graphene (Gr) and palladium nanoparticle (Pd NP) composite. The PDDA-Gr-Pd composite displayed good selectivity and high sensitivity to the targets, which were ascribed to the synergistic effect of the large surface area and good electron transfer efficiency of both Gr and Pd NPs. The electrochemical properties of sunset yellow and tartrazine on the modified electrode were investigated by cyclic voltammetry and differential pulse voltammetry. Under the optimum experimental conditions, the peak currents were linear with the concentrations of sunset yellow and tartrazine in the ranges of 0.01-10.0 and 0.05-8.0 mu mol L-1, respectively. The limit of detection (LOD) was 2.0 and 5.0 nmol L-1 for sunset yellow and tartrazine, respectively. The developed simple and sensitive method was successfully applied for simultaneous determination of sunset yellow and tartrazine in soft drinks with satisfactory results.