Glucose Oxidation on Au-Pt Nanoparticles in a Membrane-Less Biofuel Cell

The electrical performances of a membrane-less glucose/O2 biofuel cell was measured, using a biocathode composed of laccase co-immobilized with 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonate) diammonium salt (ABTS2-) on the external face of a carbon porous tube, and Au-Pt alloy nanoparticles as anode. A 40 wt. % Au-Pt/C anode catalyst was dispersed in an ultrasonically homogenized ink to be immobilized on the inner face of a carbon tube by painting. Inserting the biocathode into the anode, which has a large internal diameter, assembled the cell. O2 diffuses by porosity through the inner carbon tube to react with laccase, while the top and the bottom of the cell are sealed with two Teflon gaskets. The electrolyte (phosphate buffer 0.2 M pH 7.4) containing 10 mM glucose was analyzed by ionic chromatography with a ternary gradient of elution necessary to separate the remaining glucose from gluconic, glucuronic and glucaric acids, which were the detected reaction products.