Uric acid (UA) detection is quite important in humans as high blood concentrations of UA called Hyperuricemia can lead to Gout, diabetes and formation of kidney stones etc. In the present work, a sensitive and selective method is presented for the voltammetric determination of UA in the presence of ascorbic acid (AA) and dopamine (DA) using a carbon paste electrode (CPE) modified with benzoic acid in 0.1 M phosphate buffer solution (PBS) of pH 7 by electropolymerisation. The obtained poly(benzoic acid) modified carbon paste electrode (PBA/CPE) showed excellent electro catalytic activity for the selective detection of UA in the presence of AA and DA and it also showed good reproducibility. Its sensitivity increased 2.33 folds for the detection of UA compared to bare carbon paste electrode (BCPE). Effect of variation of scan rate on the peak current indicated that the electrode process is both diffusion controlled and adsorption controlled. The detection limit (LOD) and quantification limit (LOQ) of the present technique were found to be 3.33x10-7 M (0.333 ?M) and 1.11x0-6 M (1.11 µM) respectively for UA. pH effect suggested that equal number of protons and electrons were involved in the electrochemical oxidation of UA. The percentage of recovery of UA in real sample analysis i.e. in human urine is quite good and was found to be 100.5% using PBA/CPE. Thus, the selectivity, reproducibility and sensitivity of the PBA/CPE provide a good possibility for applying the technique in the routine analysis of selected class of electro active biomolecules.
Dopamine, Ascorbic acid, Uric acid, Cyclic voltammetry, Differential pulse voltammetry