Electrochemical sensor for simultaneous determination of uric acid, xanthine and hypoxanthine based on poly (bromocresol purple) modified glassy carbon electrode

A novel electrochemical sensor based on electroactive-polymerized film of bromocresol purple (BCP) modified on glassy carbon electrode for simultaneous determination of uric acid (UA), xanthine (XA) and hypoxanthine (HX) was presented. The preparation and basic electrochemical performance of poly (BCP) film modified glassy carbon electrode were investigated firstly in details. The electrochemical behaviors of UA, XA and HX at the modified electrode were studied by cyclic voltammetry. The results showed that this new electrochemical sensor exhibited excellent electrocatalytic activity towards the oxidation of the three analytes. The anodic peaks of the three species were well defined with lowered oxidation potential and enhanced oxidation peak currents, so the poly (BCP) modified electrode was used for simultaneous voltammetric measurement of UA, XA and HX by differential pulse voltammetry. Under the optimum conditions, the calibration curves for UA, XA and HX were obtained over the range of 0.5–120, 0.1–100 and 0.2–80 μmol L−1, respectively. The detection limits for UA, XA and HX were 0.2, 0.06 and 0.12 μmol L−1, respectively. With good selectivity and sensitivity, the proposed method has been applied to simultaneous determination of UA, XA and HX in human serum with satisfactory results.