Electrochemical detection of bisphenol A mediated by [Ru(bpy)3]2+ on an ITO electrode

A simple strategy for the direct and indirect detections of bisphenol A (BPA) at an ITO electrode is described. The direct determination of BPA in buffer solution of pH 7.2 is accomplished by the application of differential pulse voltammograms with the anodic peak at 0.546 V. The indirect approach is based on the mediation of [Ru(bpy)3]2+ (where bpy = 2,2′-bipyridine), which is served as an excellent catalyst to induce the oxidation of BPA. By monitoring the peak current of [Ru(bpy)3]2+-BPA complex, the mediated detection of BPA is successfully carried out. The response current exhibits a linear range between 5 and 120 μmol L−1 with a high sensitivity (0.22 μA μmol−1 L). The detection limit of BPA is 0.29 μmol L−1 (S/N = 3), which is larger than that analyzed by gas chromatography-mass spectrometry, however this detection method not only has the advantages of low cost and simple operation, but also provides a powerful basis for removing BPA. In addition, according to the effects of pH, scan rate and mediator concentrations on the voltammetric responses of BPA oxidation, the oxidized mechanism of BPA in the presence of [Ru(bpy)3]2+ on the ITO electrode is discussed in detail.