A Simple and Sensitive Voltammetric Method for the Determination of Orange II Based on a Functionalized Graphene-Modified Electrode

A simple and sensitive voltammetric sensor for Orange II was developed, based on a poly(sodium p-styrenesulfonate)-functionalized graphene-modified glassy carbon electrode. This voltammetric sensor showed strong accumulation ability and an excellent voltammetric response for Orange II. The electrochemical behavior of Orange II was systematically investigated in a pH 7.0 phosphate buffer solution. By linear sweep voltammetry, under optimum conditions, a good linear relationship was obtained between peak currents and Orange II concentrations in the wider range of 3 × 10−8 to 5 × 10−6 mol/L, with an LOD of 1 × 10−8 mol/L. In addition, the proposed Orange II sensor was successfully applied to real food samples with satisfactory recovery.