Selective Differential Pulse Voltammetry Determination of Uric Acid in Clinical Urine Samples Using Copper Oxide Nanoparticles Modified Pencil Graphite Electrodes

Abstract

The level of uric acid (UA) in clinical samples serves as a useful test in the diagnosis of related health disorders such as gout, hypertension & cardiovascular diseases, sclerosis, Alzheimer’s disease & optic neuritis. Interference by coexisting components of physiological fluids is a key problem to solve while attempting to demonstrate electrochemical determination of UA. CuO NPs was synthesized by aqueous chemical growth method. The deposition of the synthesized NPs on the pretreated PGE surface was carried out by drop casting of a suspension of the NPs. The current response of uric acid detection was improved by a factor of 2.63 in differential pulse voltammetric measurement compared to unmodified electrode. Under the optimized method and solution parameters, linear dependence of peak current on uric acid concentration in a wide range of 1.21x10 − 6 M to 1.142x10− 4 M, Limit of detection 6.25x10− 7 M, and limit of quantification 2.084 x10− 6 M, and excellent recovery results (90.0-99.3%) respectively. The developed sensor displayed well separated and discerned peaks for UA in presence of the potential interferent (ascorbic acid and tartaric acid). The electrode was successfully applied for the detection of UA in clinical urine samples in a phosphate buffer solution (pH = 7). The proposed sensor showed a very high reproducibility and repeatability with the relative standard deviation of 0.94%. In conclusion, a simple and low cost sensor based on PGEs is developed for sensitive and selective detection of uric acid in clinical urine samples.