High performance glucose/O2 compartment-less biofuel cell using DNA/CNTs as platform for immobilizing BOD as novel biocathode and integrated NH2-CNTs/ DEN/GDH/ NB as anode

Enzyme-modified electrodes are core components of bioelectronic devices, such as biofuel cells, which, generating electricity from natural fuels, like sugars and alcohols [1]. Different methods to electrically communicate enzymes with electrodes were developed [2,3,4]. Herein, bilirubinoxidase enzyme molecules was immobilized with control orientation using deoxy ribonucleic acid (DNA)/multi-walled carbon nanotubes (MWCNTs) modified electrode with enhancednegative charged density as novel platform. The proposed support increased the performance ofthe direct electron transfer (DET) and oxygen reduction reaction (ORR) three folds in comparison to BOD enzyme which immobilized directly onto MWCNTs and as a result thecurrent density reached to 270 A cm-2 at 0.405 V with an onset potential of 0.57V (vs. Ag/AgCl). The performance of this modified electrode as a biocathode was investigated after assembling with bioanode. The bioanode prepared with covalent attachment of glucose dehydrogenase enzyme (GDH) and nile blue (NB) as an efficient mediator for coenzyme regeneration onto glassy carbon electrode modified with amino-carbon nanotubes(MWCNTs-NH2) and carboxyl terminated polyamidoamin dendrimer (PAMAM-Den ) as a multifunctionallinker. Finally, the performance of one-compartment glucose/O2 biofuel cell without separators was also investigated. Based on the recorded polarization curves, the open circuit voltage of thecell and maximum current density were obtained 660 mV and 172 Acm-2, respectively, while the maximum power density of 45μWcm−2 was achieved at 428 mV of the cell voltage in buffer solution saturated with O2 and containing 50 mM of glucose. The stability of the constructed EBFC was investigated under continuous operation at maximum power. It was observed that the biofuel cell can retain more than 90% of its performance after 24 h. figure .1 showed the schematic representation of the constructed biofuel cell.

کلیدواژه ها:

Enzymatic biofuel cell ، Membrane less ، Glucose dehydrogenase enzyme ، Dendrimer ، Bilirubin oxidase enzyme ، oriented immobilization