Glucose biosensors based on Ag nanoparticles modified TiO2 nanotube arrays

A GOx/Ag/TiO2 glucose biosensor was achieved by photoreducing Ag nanoparticles on TiO2 nanotube arrays (NTAs) following with adsorption of GOx. The morphology, structure, and element component of Ag/TiO2 NTAs were characterized by scanning electron microscope, transmission electron microscope, and X-ray diffraction. Ag nanoparticles were uniformly deposited on surface of TiO2 NTAs with average size of 15 nm and the size and distribution changed with the immersing time of TiO2 NTAs in AgNO3 aqueous solution. Electrochemical properties of Ag/TiO2 NTAs were characterized by cyclic voltammetry and amperometric detection of H2O2, revealing that TiO2 NTAs with immersing time of 30 min achieve the best electrochemical activity. The GOx/Ag/TiO2 NTAs biosensor with optimum conditions achieves a sensitivity of 0.39μA mM−1 cm−2 with liner range from 0.1 to 4 mM.