Biofuel cells based on direct enzyme-electrode contacts using PQQ-dependent glucose dehydrogenase/bilirubin oxidase and modified carbon nanotube materials

The BP-based fuel cell exhibits maximal power density of about 107 µW/cm2 (at 490 mV). The vaCNT-based fuel cell achieves a maximal power density of 122 µW/cm2 (at 540 mV). Even after three days and several runs of load a power density over 110 µW/cm2 is retained with the second system (10 mM glucose). Due to a better power exhibition and an enhanced stability of the vaCNT-based fuel cells they have been studied in human serum samples and a maximal power density of 41 µW/cm2 (390 mV) can be achieved.