Enzymatic biofuel cells provide a safe and renewable means of powering small electronic devices. These bioelectronic devices utilize enzymes as biocatalysts at one or both electrodes. So enzyme-modified electrodes are core components of enzymatic biofuel cell. In this study, the preparation of an integrated modified electrode based on the covalent attachment of glucose dehydrogenase enzyme and safraninO to aminederivative multi walled carbon nanotubes modified glassy carbon electrode using G2.5- carboxylated PAMAM dendrimer as linking agent is reported. The proposed system has effective bioelectrocatalytic activity toward glucose oxidation at100mV with onset potential of −130mV (vs.Ag/ AgCl). The performance of the prepared hybrid system of GC/MWCNTs-NH2/Den/GDH/Safranin as anode in a membraneless enzyme-based glucose/O2 biofuel cell is further evaluated. The biocathode in this system was composed of bilirubin oxidase enzyme immobilized onto a bilirubin modified carbon nanotube GC electrode. Immobilized BOX onto CNTs/bilirubin not only shows direct electron transfer but also it has excellent electrocatalytic activity toward oxygen reduction at a positive potential of 610mV. The open circuit voltage of the cell was 590mV. The maximum current density was 0.5mAcm−2, while maximum power density of 108 μWcm−2 was achieved at voltage of 330mV. The output power of the BFC is approximately constant after12h continue operation.
