Electrochemical Kinetic Study on Various Immobilized Yeasts for Glucose Biofuel Cell Applications

Microbial fuel cells produce electricity directly from organic fuels such as glucose, sucrose, acetates and ethanol. In the present work, the electrochemical characteristics of immobilized yeasts against carbon electrode with various glucose concentrations are investigated experimentally. Three types of yeasts as anode catalyst are employed: (1) commercially available baker's yeast (S. cerevisiae); (2) wild type yeast cultured in our lab; and (3) respiration-free mutant yeast. As a baseline, non-immobilized baker's yeast is examined for comparision with the others. Kinetic parameters for the three types of yeasts are obtained by Tafel analysis. Cyclic voltammetry (CV) techniques are applied to investigate the reversibility of the redox reactions. Open current potentials (OCP) of each yeast are measured against a reference electrode to estimage the anodic potential with various glucose concentrations. Electrochemical impedance spectroscopy (EIS) of the half-cell is conducted to estimate the resistivity of the electrode and the overall ohmic resistance. With an intention to develop an in vivo glucose monitoring system, the experimental results from this fundamental kinetic study will be used as a guideline, and a novel biological glucose fuel cell is being designed.