SOL-GEL-BASED AMPEROMETRIC GLUCOSE BIOSENSOR INCORPORATING AN OSMIUM REDOX POLYMER AS MEDIATOR

A novel amperometric biosensor for the determination of glucose was co nstructed by first immobilizing glucose oxidase and an osmium redox po lymer, [Os(bpy)(2)(PVP)(10)Cl]Cl, on the surface of a glassy-carbon el ectrode, followed by coating with a sol-gel film derived from methyltr iethoxysilane. The redox potential of this electrode was found to be 247 mV versus Ag/AgCl, and glucose could therefore be determined amper ometrically at +400 mV versus Ag/AgCl. The concentration range of line ar response, slope of linear response and LOD were 2.0-31 mmol l(-1), 44.5 nA mmol(-1) I and 0.5 mmol l(-1), respectively, Although L-ascorb ate was electrooxidizable at this potential, uric acid and paracetamol were both found not to interfere.