Novel helical TiO2 nanotube arrays modified by Cu2O for enzyme-free glucose oxidation

A helical TiO2 nanotube (TNT) array modified with cuprous oxide (Cu2O) electrode was fabricated and used for nonenzymatic glucose detection. The structure and morphology of Cu2O/TNT were characterized by X-ray diffraction and transmission electron microscopy. The electrocatalytic performance of Cu2O/TNT electrode for glucose oxidation was investigated by cyclic voltammetry and chronoamperometry. At an applied potential of +0.65 V versus SCE, a linear range was obtained within the concentration range of 3.0-9.0 mM with a detection limit of 62 μM (signal/noise=3). The response time was approximately 3 s after adding 0.10 mM glucose. Formate and gluconic acid were identified as the main products of the glucose oxidation using (1)H NMR spectrometry. A possible mechanism for continuous glucose oxidation was also proposed.