Microfluidic biofuel cell based on cholesterol oxidase/laccase enzymes.

Abstract

In this research two electrodes were developed, a bioanode where the enzyme oxidase was immobilized on Sigracet GDL 39 by means of the covalent binding method and a biocathode with laccase enzyme immobilized on Toray carbon paper by the adsorption method. The evaluation of these electrodes was carried out in a microfluidic fuel cell using cholesterol as fuel and oxygen as oxidant. The electrical conductivity of the electrodes was measured by the kelvin method. Microfluidic fuel cell (mFFC) was constructed using Poly-(methyl methacrylate) (PMMA) for the fuel and oxidant channels; the cathode electrode was incorporated as a wall to obtain the major O2 quantity for the reduction reaction. The evaluation of the microfluidic cell was carried out using different solutions of cholesterol all in phosphate buffer solutions at pH 7.5, where it was possible to obtain 1.38 mW/cm2 of maximum power density and 0.75V of open circuit potential using 500mg/dL of cholesterol.