Biofuel cells based on direct enzyme–electrode contacts using PQQ-dependent glucose dehydrogenase/bilirubin oxidase and modified carbon nanotube materials
By Scherbahn, V.; Putze, M.T.; Dietzel, B.; Heinlein, T.; Schneider, J.J. & Lisdat, F.
Published in Biosensors and Bioelectronics
2014
Abstract
Two types of carbon nanotube electrodes (1) buckypaper (BP) and (2) vertically aligned carbon nanotubes (vaCNT) have been used for elaboration of glucose/O2 enzymatic fuel cells exploiting direct electron transfer. For the anode pyrroloquinoline quinone dependent glucose dehydrogenase ((PQQ)GDH) has been immobilized on [poly(3-aminobenzoic acid-co-2-methoxyaniline-5-sulfonic acid), PABMSA]-modified electrodes. For the cathode bilirubin oxidase (BOD) has been immobilized on PQQ-modified electrodes. PABMSA and PQQ act as promoter for enzyme bioelectrocatalysis. The voltammetric characterization of each electrode shows current densities in the range of 0.7–1.3 mA/cm2. 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.