ADVANCED AMPEROMETRIC BIOSENSORS

THIS PROPOSAL DESCRIBES THE DESIGN AND TESTING OF A NEW CLASS OF AMPEROMETRIC GLUCOSE SENSOR IN WHICH ELECTRICAL COMMUNICATION BETWEEN THE FLAVIN REDOX CENTERS OF GLUCOSE OXIDASE AND AN ELECTRODE IS ACHIEVED VIA A NETWORK OF DONOR-ACCEPTOR RELAYS CHEMICALLY BOUND TO A POLY(ETHYLENE OXIDE), OR PEO, BACKBONE. THESE POLYMERIC RELAY SYSTEMS COMBINE SEVERAL IMPORTANT FEATURES FOUND IN PREVIOUS POLYMERIC ELECTRON TRANSFER RELAY SYSTEMS: (A) A FLEXIBLE POLYMER BACKBONE; (B) THE RELAYS ARE ATTACHED TO FLEXIBLE SIDE CHAINS; (C) PEO EFFECTIVELY COMPLEXES SIMPLE CATIONIC SPECIES, SUCH AS K(+) AND NA(+), WHICH CAN GIVE THE POLYMER ITSELF SOME CATIONIC CHARACTER AND INCREASE THE INTERACTION BETWEEN THE POLYMER AND THE NEGATIVELY CHARGED GLUCOSE OXIDASE MOLECULES. THE PROPOSED RESEARCH PLAN FOR PHASE I CONCERNS THE DEVELOPMENT OF THIS CLASS OF SENSOR THROUGH THEFOLLOWING APPROACH: (A) SYNTHESIS AND ELECTROCHEMICAL CHARACTERIZATION OF SEVERAL MEDIATOR (FERROCENE)-CONTAINING PEO MATERIALS; (B) STUDY OF THE INTERACTION BETWEEN THE FLAVIN REDOX CENTERS OF GLUCOSE OXIDASE AND THE PEO-BOUND ELECTRON TRANSFER RELAY SYSTEM THROUGH INVESTIGATION OF THESE NEW FLEXIBLE POLYMERS IN ENZYME ELECTRODE CONFIGURATIONS; (C) COVALENT ATTACHMENT OF GLUCOSE OXIDASE TO FERROCENE-MODIFIED PEO IN ORDER TO FURTHER INCREASE THE INTERACTION BETWEEN THE ENZYME AND THE MEDIATORS, TO MINIMIZE COMPETITIVE REOXIDATION OF REDUCED GLUCOSE OXIDASE BY DISSOLVED OXYGEN, AND TO IMPROVE THE LONG-TERM STABILITY OF THE SENSOR.