Detection of uric acid based on doped ZnO/Ag2O/Co3O4 nanoparticles fabricated glassy carbon electrode

A highly sensitive uric acid (UA) sensor was fabricated using wet-chemically (co-precipitation) prepared doped ZnO/Ag2O/Co3O4 nanoparticles (NPs) onto glassy carbon electrode (GCE) by electrochemical approach. The detail characterization of NPs were performed by using conventional methods, such as X-ray photoelectron spectroscopy (XPS), ultraviolet–visible spectroscopy (UV-vis.), Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), Tunneling electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray powder diffraction (XRD) analysis. Thermal gravimetric analysis (TGA) of the as prepared ternary NPs is performed in order to study the stability of NPs in different temperature range over which the weight loss and thermal effect are significant. During electrochemical analysis, the proposed UA sensor was found to be linear over large linear dynamic range (LRD; 0.1 nM~0.01 mM). The sensor analytical performance such as sensitivity (82.3323 µAµM-1cm-2) was estimated from the slope of calibration curve and detection limit (89.14 ±4.46 pM) was calculated at signal to noise ratio of 3. The proposed UA biosensor was showed the reliable reproducibility, response time (22.0 sec.), long-term stability, and no interferences effects. The ZnO/Ag2O/Co3O4 NPs/GCE sensor was also validated with the real samples. Thus, the process using this method might be a prospective and reliable method to the future development of enzyme-free biosensor using doped ternary metal oxides in broad scales.