Modification of glassy carbon electrode with NiO nanoparticles prepared using Ocimum sanctum leaf extract as urea sensor

NiO nanoparticles (NiO NPs) have been prepared with green synthesis method using Ocimum sanctum leaf extract (OSLE), which contains secondary metabolite compounds of alkaloids as a weak base source and capping agent. Characterization using Particle Size Analyser (PSA) showed a particle size of NiO about 52.42 nm. NiO NPs was used as modified on glassy carbon (GC) electrode, and then characterized using cyclic voltammetry (CV) and Scanning Electron Microscopy-Energy Dispersive X-Ray (SEM-EDX). GC-NiO NPs was used for preliminary studies of urea sensor. The results showed that GC-NiO NPs can detect urea with limit of detection (LOD) values of 0.12 mM and linearity R² of 0.97. In addition, the repeatability of urea sensor studies with GC-NiO NPs electrode shows % RSD of 2.854, while its stability shows % RSD of 7.90 for 3 days.