Electrodeposition of quercetin on the electrospun zinc oxide nanofibers and its application as a sensing platform for uric acid

In a current study, a distinctive voltammetric method was developed for the determination of uric acid (UA) at a carbon paste electrode (CPE) modified with zinc oxide nanofibers (ZNFs) and quercetin (Q). ZNFs were fabricated via the electrospinning process. The electrode was prepared by electrodeposition of quercetin on a zinc oxide nanofiber carbon paste electrode (Q/ZNFs/CPE). The Q/ZNFs/CPE offered substantially lower overpotential for electro-oxidation of UA in acetate buffer solution (ABS) (pH 4.45) compared with Q/CPE, ZNFs/CPE and bare CPE. Furthermore, the effects of pH, scan rate, accumulation time and potential, interference effect and effect of quercetin electrodeposition on the surface of ZNFs/CPE were studied in detail. The studies suggested that the electrode reaction process was totally irreversible and adsorption controlled. Differential pulse voltammogram peak current of UA increased linearly with its concentration within two dynamic ranges and detection limit for UA was 0.05 mu mol L-1 with RSD = 02%. The prepared electrode was applied for determination of UA levels in serum and plasma of a healthy person and the patient with leukemia. The results indicated that the proposed method was sensitive, selective, fast and simple for determination of UA. (C) 2014 Elsevier B.V. All rights reserved.