Simultaneous electrochemical determination of ascorbic acid, dopamine and uric acid based on reduced graphene oxide-Ag/PANI modified glassy carbon electrode

An electrochemical method for simultaneous determination of ascorbic acid(AA), dopamine(DA) and uric acid(UA) was developed based on RGO-Ag/PANI modified glassy carbon electrode(RGO-Ag/PANI/GCE, RGO= reduced graphene oxide, PANI=polyaniline). Owing to the synergetic effect among RGO, Ag and PANI, the RGO-Ag/PANI based sensor not only improved the electrochemically catalytic oxidation of AA, DA and UA, but also resolved the overlapping anodic peaks. Under the optimized conditions, the calibration curves were obtained in the concentration ranges of 50—1000, 5—200 and 20—350 μmol/L, and the detection limits(S/N=3) of 0.5, 0.2 and 0.2 μmol/L were obtained for AA, DA, and UA, respectively, in neutral phosphate buffer solutions(PBS). The RGO-Ag/PANI/GCE sensor was successfully applied to the determination of AA, DA, and UA in bovine serum samples and showed high selectivity, sensitivity, and reproducibility.