GREEN SYNTHESIS OF Cu, Ni AND CuNi ALLOY NANOPARTICLES USING ROSMARINUS OFFICINALIS PLANT EXTRACT: EVALUATION OF ELECTROCATALYTIC ACTIVITY OF CORRESPONDING METALLIC OXIDES

Uric acid (UA) detection is extremely necessary in both blood serum and urine. High UA concentration in blood serum may induce several diseases. It is very important to develop new methods based on their ecofriendly nature for synthesis new materials used in the detection of UA for diagnosing both hyperuricemia and hypouricemia. This study aimed to synthesis copper, nickel, and copper nickel alloy nanoparticles (NPs) by green voice using Rosmarinus officinalis plant aqueous extract at room temperature. Reduction to CuNPs, NiNPs, and CuNi alloy NPs was confirmed by UV-Vis analysis. The IR analysis is used to identify the chemical group present on the synthesized NPs. Scanning electron microscopy (SEM) shows nearly spherical shape of NPs, X Ray diffraction (XRD) pattern shows face cubic center (fcc) structure and the crystallite range size was estimated to be about 19–49nm. Then, the synthesized NPs were calcined at 500∘C and characterized by XRD witch confirmed the presence of NPs oxide. These oxidized NPs were used as catalysts to modify carbon paste electrode (CPE) in the study of the electrocatalytic determination of UA by using cyclic voltammetry technique. The result showed that the modified electrodes CPE with 10%CuO, 5%NiO, and 10%CuNiO alloy present the better electrocatalytic activity than uncalcined NPs modified electrodes toward the UA oxidation in phosphate buffer (pH=6), and exhibited oxidation potential peaks at 515, 541, and 481mVSCE, respectively. The 10%CuNiO/CPE electrode gives a good sensitivity (17.58μ AmM−1) towards UA oxidation compared with the 10%CuO/CPE (6.83μ AmM−1) and 5%NiO/CPE (10.74μAmM−1) electrodes. The detection limits were found to be equal to 100, 100, and 50μ M for 10%CuO/CPE, 5%NiO/CPE, and 10%CuNiO/CPE, respectively, in awide range of UA concentration. These electrodes also exhibited a high selectivity towards UA in the presence of other interference as well as can be applied for the detection of UA in human urine.