NOVEL BIOSENSORS FOR SPECFIC NEUROTRANSMITTERS

THIS PROJECT WILL DESIGN AND TEST NEW ENZYME-BASED AMPEROMETRIC SENSORS FOR THE NEUROTRANSMITTERS ACETYLCHOLINE, GLUTAMATE, AND ASPARTATE, IN WHICH ELECTRICALCOMMUNICATION BETWEEN THE FLAVIN REDOX CENTERS OF AN OXIDASEAND AN ELECTRODE IS ACHIEVED VIA A NETWORK OF DONOR-ACCEPTORRELAYS CHEMICALLY BOUND TO A FLEXIBLE SILOXANE POLYMER. BECAUSE THE ELECTRON TRANSFER MEDIATORS ARE COVALENTLY ATTACHED TO AN INSOLUBLE POLYMER AND CANNOT DIFFUSE AWAY FROM THE ELECTRODE, THESE SENSORS SHOULD BE SUITABLE FOR IMPLANTATION AND THUS WOULD BE USEFUL FOR IN VIVO NEUROCHEMICAL RESEARCH. PHASE I RESEARCH WILL DEVELOP THESE SENSORS, USING THE FOLLOWING APPROACH: CONSTRUCT REDOX POLYMER-MODIFIED SENSORSCONTAINING ACETYLCHOLINESTERASE AND CHOLINE OXIDASE (FOR ACETYLCHOLINE DETECTION), L-GLUTAMATE OXIDASE (FOR GLUTAMATEDETECTION), AND L-ASPARTATE OXIDASE (FOR ASPARTATE DETECTION); VARY THE NUMBER OF POLYMER-BOUND ELECTRON RELAYS, WHICH WILL OPTIMIZE THE SENSOR RESPONSE TO SUBSTRATE, MINIMIZE THE OPERATING VOLTAGE TO DECREASE ANY INTERFERENCE DUE TO EASILY OXIDIZABLE SPECIES, AND ELIMINATEANY DECREASE IN RESPONSE DUE TO DISSOLVED OXYGEN. IN ADDITION, IN ORDER TO INCREASE THE RESPONSE TO ACETYLCHOLINE, ELIMINATE INTERFERENCE DUE TO SPURIOUS ANIONIC SPECIES, AND PREVENT SENSOR FOULING, A COMMERCIALLY AVAILABLE ANIONIC POLY(ESTER SULFONIC ACID) WILL BE USED TO COAT THE ACETYLCHOLINE SENSOR.