Photoexcited CuO/TiO₂ Heterojunction for Photoelectrochemical Sensors for Nonenzymatic Glucose Detection

Photoelectrochemical sensors have been studied for glucose detection because of their ability to minimize background noise and unwanted reactions. Titanium dioxide (TiO₂), a highly efficient material in converting light into electricity, cannot utilize visible light. In this regard, we developed a nonenzymatic glucose sensor by using a simple one-step electrospinning technique to combine cupric oxide with TiO₂ to create a heterojunction. The prepared nanofibers exhibit an extremely high aspect ratio and have a dense structure. These characteristics enhance the quantity of electron-hole pairs generated by light and the speed at which electrons are transferred. They also reduce the distance that charges need to travel and offer reactive sites for the catalytic oxidation of glucose. The sensor has a direct and proportional reaction within glucose concentration ranging from 30 μM to 2 mM under sunlight conditions. It achieves a detection limit of 9.9 μM with a signal-to-noise ratio of 3. The sensors also exhibit excellent stability, reproducibility, and selectivity. This study provides insights for development of photoelectrochemical sensors to detect glucose.