Performance of non-compartmentalized enzymatic biofuel cell based on buckypaper cathode and ferrocene-containing redox polymer anode

Novel single compartment Glucose/O2 biofuel cells (BFCs) were developed using immobilized enzymes and the mediated electron transfer (MET) approach. The bioanode was prepared through a ferrocene-containing redox polymer crosslinked in the presence of a biocatalyst on a glassy carbon support. Here, the redox polymer can physically entrap the enzyme and prevent it from leaching. Additionally it provides a biocompatible microenvironment and thus could extend the life time of enzyme. On the other side, the mediated biocathode was prepared based on bilirubin oxidase and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) diammonium salt (ABTS2−) system which has been physically entrapped in Nafion matrix and then adsorbed directly on a highly porous, conductive and functionalized buckypaper (fBP). Both electrodes were characterized physically and electrochemically. Employing these electrodes, the resulting BFC generates an open circuit voltage (Voc) of approximately 0.550 V and a peak power density of 26 μW cm−2 at 0.2 V at 37 °C in quiescent O2-saturated physiological buffer containing 5 mM glucose. The cell sustains a load up to 225 μA cm−2. Moreover, a high short circuit current (Isc) of 300 μA cm−2 is approached. This BFC can operate in mild conditions without using any toxic materials which makes it attractive for implantable devices.