Highly sensitive enzyme-less electrochemical glucose sensor based on copper oxide-multi-walled carbon nanotube (MWCNT) composite (CuO-MWCNT) modified glassy carbon electrode (GCE) was prepared by co-precipitation method. The as-prepared nanocomposites were characterized by field emission scanning electron microscope (FE-SEM), Raman spectroscopy, Fourier transform infrared spectroscopy and electrochemical analyses. The electrochemical results of cyclic voltammetry (CV) and chronoamperometry demonstrated that the CuO-MWCNT/Nf/GCE showed high electrocatalytic activity than the copper oxide nanoleaves (CuO-Nls) modified electrode toward glucose. The modified electrode showed enhanced electrocatalytic behaviour towards glucose in alkaline medium. The non-enzymatic glucose sensor based on CuO-MWCNT/Nf/GCE showed the highest sensitivity of 1038.6 µA mM⁻¹cm⁻² with the lowest detection limit of 0.1 µM (signal/noise ratio (S/N) = 3) under optimal experimental conditions. The fabricated sensor showed good accuracy, reproducibility and stability. The sensor was highly selective to detect the glucose in the presence of other common interfering species like ascorbic acid, uric acid and dopamine. Additionally, its application for detecting glucose concentration of human urine sample showed good agreement with the results obtained from automatic biochemical analyzer.

Keywords: CuO-MWCNT nanocomposites; electrocatalytic activity; cyclic voltammetry (CV); chronoamperometry; accuracy; reproducibility; stability