(92d) Characterization of an Enzymatic Fuel Cell Biocatalized by Glucose Oxidase (Gox) with Electrochemcial Impedance Spectroscopy (Eis) and Cyclic Voltammetry (CV)

Given the existing energy crisis, concerns with oil dependence and environmental contamination concerns and depletion of fossil fuels, research interest in the optimization and developing of different types of Fuel Cells has increased. One of these systems, the Enzymatic Fuel Cell, whose reactions are biocatalized by enzymes like Glucose Oxidase (GOx) is the main topic of this research. Electrode contacting of redox-enzymes with electrodes is a major goal for developing amperometric biofuel cells, biosensors and bioelectronic elements. Self-assembled monolayers (SAMs) provide an attractive route for these applications. The ?standard? procedure for SAM formation and compatibility with metal substrates (i.e. Au, Pt, Ag) for electrochemical measurements enable special benefits for these applications involving current and potential measurements. Formation of SAM is essentially an organization of molecules at the solid-liquid interfaces induced by strong chemisorption between the substrate and the head group (i.e. thiols, disulfides). Traditional methodologies to reconstitute the GOx enzyme on the relay-Flavine Adenine Dinucleotide (NAD+) monolayer for glucose electroxidation involves an elaborate synthesis of the FAD+ cofactor, limiting its practical utility. Electrochemical techniques such as Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) will be used to characterize the Cystamine Monolayer and its behavior in the presence of glucose prior to the characterization of a commercial glucose electrode. The monolayers are formed by two-step process. The first step is to treat the electrode electrochemically with a buffer solution (pH = 7.0) in the presence of the redox couple K3Fe(CN)6 to find the redox peaks for gold (Au) and platinum (Pt) by cycling in a potential range of -1.5 to 1.5V. Then, the electrode is treated with the thiol solution resulting in a monolayer formation. Also Nyquist plots of EIS in the frequency range of 10-1000 kHz will be used to illustrate the oxidation rates and the resistances for electron transfer of our system.