Novel single compartment Glucose/O-2 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 (ABTS(2-)) system which has been physically entrapped in Nation 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 (V-oc) of approximately 0.550 V and a peak power density of 26 mu W cm(-2) at 0.2 V at 37 degrees C in quiescent O-2-saturated physiological buffer containing 5 mM glucose. The cell sustains a load up to 225 mu A cm(-2). Moreover, a high short circuit current (I-SC) of 300 mu A cm(-2) is approached. This BFC can operate in mild conditions without using any toxic materials which makes it attractive for implantable devices. (C) 2013 Elsevier B.V. All rights reserved.