Ti/TiO2 Nanotube Array/Ni Composite Electrodes for Nonenzymatic Amperometric Glucose Sensing

TiO2 nantube arrays (NTAs) with a tube diameter of about 100 nm were prepared by anodic oxidation, and a Ni layer about several tens of micrometers thick was electrodeposited on the surface of TiO2 NTAs. The synthesized Ti/TiO2 NTA/Ni composite electrodes were used for nonenzymatic glucose detection. The behavior of the anodic TiO2 NTA/substrate Ti metal is analogous to characteristics of an n-type semiconductor/metal Schottky barrier diode. The characteristic would enhance the rapid transport of surface reaction electrons to the metal substrate, thereby enhancing the performance of biosensors. Cyclic voltammogram investigations indicate that calcined Ti/TiO2 NTAs have a wider work potential window than that of Ti/TiO2 NTAs without calcinations and Ti foils. Moreover, the low saturated current in alkaline solutions under a constant potential makes Ti/TiO2 NTAs favorable as substrate materials for biosensors. For the Ti/TiO2 NTA/Ni composite electrodes, the relationship between the linear range and the pot...