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

We report on a high performance glucose biosensor based on the immobilization of glucose oxidase (GOx) with chitosan onto TiO2 nanotube arrays modified by Prussian blue (PB) and Au. The titania nanotube arrays were grown directly on a Ti substrate using anodic oxidation, with a thin Au film coated onto the TiO2 nanotube arrays by an argon plasma technique, followed by the electrodeposition of PB. The morphology and composition of the fabricated TiO2 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 biosensor. Applied potential, pH, and the effect of interferences have been systemically studied. Our results show that the modified TiO2 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 biosensor exhibits a high sensitivity 36 mu A mM(-1) and very low detection limit of 5 mu M. (C) 2008 Elsevier B.V. All rights reserved.