Electrochemical determination of glucose in beverages intended for athletes using a CuO-based nanocomposite sensor

This study presents the development of a highly sensitive nonenzymatic glucose sensor based on a g-C₃N₄-CuO composite-modified glassy carbon electrode (GCE). CuO nanoparticles were effectively deposited on graphitic carbon nitride (g-C₃N₄) to fabricate the sensor. The integration of g-C₃N₄-CuO as a modifier significantly enhances the surface properties of the modified GCE, facilitating improved electron transfer and an increased number of active sites for glucose oxidation in NaOH solution. The electrochemical characterization of the modified electrode was performed using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques, revealing excellent electrochemical properties. The suggested methodology exhibited a broad calibration range from 3 to 650 µM and an impressively low detection limit of 0.5 µM. The anti-interference property was evaluated against several potential interferents, including dopamine, ascorbic acid, uric acid, L-cysteine, lactose, and sucrose, demonstrating high selectivity for glucose detection. Additionally, real sample analysis conducted on sports drinks confirmed the practical applicability and accuracy of the sensor. In addition, the sensor presented remarkable reproducibility and satisfactory storage stability. The proposed sensing platform provides a practical and promising analytical tool for nonenzymatic glucose detection in food industry applications.