We provide a new organic–iorganicnanocomposite for enzyme immobilization.The composite consisting of modified TiO2 with 2,2'-dithioxo-3,3'-bis(3-(triethoxysilyl)propyl)- 2H,2'H-[5,5'-bithiazolylidene]-4,4'(3H,3'H)-dione(DTP)and graphene.DTP as covalently attached to the ofsurfaceTiO2 nanoparticles and employed for obtaining a suitable solid surface to enzyme attachment.In this work glucose oxidase (GOx) was irreversibly immobilized on the titanium oxide nanoparticle (TiO2/ DTP) using consecutive cyclic voltammetry.The enzyme immobilization and the enzymatic activity were determined by UV/vis Spectroscopy and Electrochemical method.The results implied to significant rule of DTP on the enzyme immobilization.Direct electrochemistry and electrocatalytic activity of modifiedelectrode were evaluated by voltammetric techniques.The cyclic voltammogram displayed a pair of well-defined and nearly symmetric redox peaks with a formal potential of-460mV and an apparent electron transfer rate constant of 5.8 s-1. The GOx/TiO2-DTP can catalyze the electroreduction and electrooxidation of hydrogen peroxide formed from enzymeatic oxidation of glucose.The modified electrode shows excellent activity toward direct oxidation of glucose in presence of ferocene methanol as an artificial redox mediator.The glucose biosensor shows fast amperometric response (3s) with good stability, linear calibration range, high sensitivity and low detection limit.
