Enhancement of Bioelectrocatalytic Oxidation of Glucose by Application of Tetrathiafulvalene Modified Carbon Nanotubes as Mediating System

Abstract

Combination of tetrathiafulvalene (TTF)-modified multi-walled carbon nanotubes and glucose oxidase within the film produces a bio-electrocatalytic system capable of effective oxidation of glucose in 0.1 mol dm-3 phosphate buffer (pH=7.0). An important function of carbon nanotubes is to improve transport of electrons within the film. Here carbon nanotubes have been modified with ultra-thin layers of TTF to form stable colloidal suspensions of carbon nanostructures. They have been utilized to produce Nafion-containing inks for sequential deposition of components. The presence of TTF is expected to facilitate an effective flow of electrons from the redox centers of glucose oxidase to the glassy carbon electrode. TTF constitutes a group of redox molecules that were successfully used as redox mediators in enzyme electrochemistry. Our highly porous film of carbon nanotubes on the electrode surface have presumably acted as three-dimensional network of nanowires around the enzyme molecules and have promoted the efficient electron transfers.