An "abiotic" biofuel cell composed of catalytic electrodes modified with inorganic nanostructured species was used to activate a pacemaker. The catalytic nanoparticles of various compositions, AuxPty, deposited on carbon black (CB) were prepared and extensively characterized to select the species with selectivity for glucose oxidation and oxygen reduction. Then two kinds of 3D-electrode materials with different morphology, buckypaper composed of carbon nanotubes (ca. 50 nm diameter) and carbon paper made of carbon fibers (ca. 7 mm diameter), were used in a combination with different catalytic species. Finally, Au/CB nanospecies deposited on buckypaper were selected for catalyzing glucose oxidation (composing the biofuel cell anode) and Au60Pt40/CB species deposited on carbon paper were selected for catalyzing oxygen reduction (composing the biofuel cell cathode). The catalytic electrodes were characterized by cyclic voltammetry in an aqueous buffer solution and the polarization function for the biofuel cell was studied in a human serum solution. The open circuit voltage, V-oc, short circuit current density, j(sc), and maximum power produced by the biofuel cell, P-max, were found as 0.35 V, 0.65 mAcm(-2) and 104 mu W, respectively (in human serum at 5.4 mM glucose). The biofuel cell produced the steady state open circuit voltage over 10 hours with its slow decrease over 50 hours originating from the glucose depletion and slow mass-transport within the 3D-electrode. The voltage produced by the biofuel cell was amplified with an energy harvesting circuit and applied to a pacemaker resulting in its proper operation. The present study continues the research line where different implantable (enzyme-based or abiotic) biofuel cells are used for the activation of biomedical electronic devices, e. g., pacemakers.