ELECTRODEPOSITION LEADING TO IMMOBILIZED ENZYME BIOSENSOR ELECTRODES

A NEED EXISTS FOR NEW ELECTROCHEMICAL SENSORS CAPABLE OF RELIABLY MEASURING CHEMICAL AND BIOLOGICAL COMPOUNDS IN THE ENVIRONMENT, PROCESS STREAMS AND IN BODY FLUIDS. ELECTROCHEMICAL SENSORS BASED ON ENZYME SPECIFICITY HAVE BROAD POTENTIAL IN MEDICAL DIAGNOSTICS, ENVIRONMENTAL MONITORING, AND PROCESS CONTROL. MAJOR PROBLEMS IN CURRENT COMMERCIAL BIOSENSOR DESIGN ARISE BECAUSE OF INSTABILITY, SLOW RESPONSE AND LACK OF DIRECT, EFFICIENT ELECTRICAL COUPLING BETWEEN THE ENZYME AND THE ELECTRODE SURFACE. THE SUCCESSFUL WORK OF THE ENZYME TECHNOLOGY RESEARCH GROUP, INC. AND DUKE UNIVERSITY SCIENTISTS ON ELECTRODEPOSITED COLLOIDAL GOLD BIOSENSOR ELECTRODES OFFERS A ROUTE TO NEW MULTI-ANALYTE SENSORS WITH DESIRABLE CHARACTERISTICS. OUR OBJECTIVE IS TO ELECTRODEPOSIT COLLOIDAL GOLD CONTAININGA TEST ENZYME ON CARBON RODS, AND OTHER INEXPENSIVE CONDUCTING MATERIALS, IN A MANNER THAT MAINTAINS BIOLOGICAL ACTIVITY OF THE ENZYME WHILE PROVIDING FOR FACILE ELECTRON TRANSFER. THE RESEARCH TASKS WILL CONSIST OF: 1) IMMOBILIZATION OF THE TEST ENZYME ON COLLIDAL GOLD PARTICLESBY EACH OF TWO METHODS (ADSORPTION DIRECTLY ON THE SURFACE AND COVALENT ATTACHMENT VIA A SPACER ARM);2) PRODUCTION OF ELECTRODES FROM THE COLLOIDAL GOLD CONTAINING THE ATTACHED TEST ENZYME BY AN ELECTRODEPOSITION METHOD; 3) MEASURING THEACTIVITY OF THE IMMOBILIZED ENZYME; AND 4) COUPLING THE ELECTRON TRANSFER CHARACTERISTICS OF THE IMMOBILIZED TEST ENZYME TO THE ELECTROACTIVE GOLD SURFACE. THE RESULTS WILL DEMONSTRATE THE FEASIBILITY OF THE ELECTRODEPOSITION METHOD TO PRODUCE ADVANCED BIOELECTRODES, AND LAY THE FOUNDATION FOR PHASE II WORK. THIS RESEARCH WILL BRING ABOUT A NEW GENERATION OF MULTI-ANALYTE, MULTI-SIGNAL, SPATIALLY RESOLVED ELECTROCHEMICAL BIOSENSORS WITH BROAD POTENTIAL AS ANALYTICAL DEVICES.