The thesis is focused on an entirely new class of electric power biodevices –self-charging biosupercapacitors, or in other words, charge-storing biofuelcells. The power generating segments of these biodevices rely on differentredox enzymes electrically wired to electrode surfaces. Planar electrodes wereadditionally nanostructured by gold nanoparticles to increase the real surfacearea/enhance enzyme loading. Bilirubin oxidase was used as a cathodicbiocatalyst responsible for oxygen electroreduction, whereas cellobiosedehydrogenase and glucose dehydrogenase were exploited as anodicbioelements catalyzing electrooxidation of glucose. The charge-storingsegments of biosupercapacitors were based on different electroconductingpolymers, including carbon nanotube based nanocomposites, and osmiummodified redox hydrogels. The particular bioelectrodes were characterized indetail using scanning electron and atomic force microscopies, as well asvarious electrochemical techniques. Self-charging biosupercapacitors wereassembled and basic parameters of the biodevices, viz. open-circuit voltages,power and charge densities, and stability, were studied in continuous andpulse operating modes.