Abstract
Constructing metal-oxide-based composites with the multiple valence-states and redox-couples has been proved as an effective strategy to enhance the performance of non-enzymatic glucose sensing. Herein, we report a mild and efficient method to prepare multiple-valent copper-based oxide composite nanofibers (CuxO CNFs) through introducing the TiO2 photosensitizer into the CuO NFs for actuating the localized phase transition from tenorite CuO (Cu2+) to cuprite Cu2O (Cu+) upon UV–visible light irradiation. The sensitivity of the obtained TiO2/Cu2O/CuO CNFs for glucose sensing (0–2 mM) could be enhanced by 1.12–1.31 times as compared to that of the TiO2/CuO CNFs. The enhanced sensitivity is dependent on the TiO2-content in the primal TiO2/CuO CNFs. When introducing 5.0 at.% of TiO2 into the CuO nanofibers, the photoinduced phase-transition process could result in the formation of optimal TiO2/Cu2O/CuO CNFs with the component ratio of Cu2O to CuO at 0.46:1. This TiO2/Cu2O/CuO CNFs (2074.7 μA·mM?1·cm?2; 0.25 μM) exhibited nearly 1.32-fold improvement on the sensitivity and 3.0-fold enhancement on the detection limit as compared to the corresponding values of the pure CuO electrospun nanofibers (1581 μA·mM?1·cm?2; 0.75 μM). After the continuous measurements for 14 days, the sensitivity of the optimal sample could maintain 89.4% of its initial value. Notably, its sensitivity could be further recovered to 97.4% of the initial value after UV–visible light irradiation for 1 h.
NSTL
Elsevier