High performance glucose biosensor based on the immobilization of glucose oxidase onto modified titania nanotube arrays

摘要

We report on a high performance glucose biosensor based on the immobilization of glucose oxidase (GOx) with chitosan onto TiO_2 nanotube arrays modified by Prussian blue (PB) and Au. The titania nano-tube arrays were grown directly on a Ti substrate using anodic oxidation, with a thin Au film coated onto the TiO_2 nanotube arrays by an argon plasma technique, followed by the electrodeposition of PB. The morphology and composition of the fabricated TiO_2 nanotube arrays were characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Cyclic voltammetry and amperometry were used to study and to optimize the performance of the resulting electrochemical bio_sensor. Applied potential, pH, and the effect of interferences have been systemically studied. Our results show that the modified TiO_2 nanotube arrays provide excellent matrices for the immobilization of GOx and that the proposed electrochemical biosensor exhibits a very low detection limit, high stability and very good reproducibility towards the detection of glucose. Under the optimized conditions, the biosen_sor exhibits a high sensitivity 36 _A mM~(-1) and very low detection limit of 5 _M.