Simultaneous electrochemical determination of dopamine, ascorbic acid and uric acid using poly(acid chrome blue K) modified glassy carbon electrode

A novel polymerized film of acid chrome blue K (ACBK) was prepared on the surface of a glassy carbon electrode (GCE) by electropolymerization, and then the modified electrode was successfully used to simultaneously determine dopamine (DA), ascorbic acid (AA) and uric acid (UA). The characterization of electrochemically synthesized poly-ACBK film was investigated by atomic force microscopy (AFM), attenuated total reflection (ATR)–FTIR, electrochemical impedance spectroscopy (EIS) and voltammetric methods. The poly-ACBK modified GCE exhibited excellent electrocatalytic activity towards the oxidations of DA, AA and UA in 0.05 mM phosphate buffer solution (pH 4.0). The separations of anodic peak potentials of AA/DA, DA/UA and AA/UA on this modified electrode are 193, 166 and 359 mV in DPV, respectively. Under the optimum conditions, the calibration curves for DA, AA and UA were obtained in the range of 1.0–200.0, 50.0–1000.0 and 1.0–120.0 μM, respectively. The detection limits (S/N = 3) were 0.5, 10.0 and 0.5 μM for DA, AA and UA, respectively. With good selectively and sensitivity, the present method was applied to the determination of DA in dopamine hydrochloride injections, AA in vitamin C tablets and UA in urine samples.