Voltammetric analysis of uric acid by zinc-nickel nanoalloy coated composite graphite

The nanocrystalline single-phase γ-Zn3Ni alloy modified composite graphite (nano-γ-Zn3Ni/CG) was employed for the detection of uric acid (UA) by voltammetric techniques. The non-enzymatic modified electrode had an excellent response and specificity for the electrocatalytic oxidation of UA in 0.2 M phosphate buffer (PB) (pH 7.0) at 280 mV vs. Ag/AgCl as compared to bare CG electrode at 360 mV. A limit of detection (S/N = 3) at 0.2 μM and concentration linear range of 1–400 μM UA were obtained. The presence of ascorbic acid (AA) did not interfere in the measurement. The nano-γ-Zn3Ni/CG was used for the determination of UA in untreated human urine and serum samples with satisfactory results.