Abstract: Electrodes for the electrochemical regeneration of the co-enzymes, NADH, NADPH or analogs thereof. The electrode surface has been modified by adsorbing thereto a condensed aromatic ring system comprising at least three, preferably four or more, condensed aromatic rings. A method of preparing the electrodes is also described, in which a condensed aromatic ring system is adsorbed to the surface of carbon or a graphitic material. Finally, there is described the use of said electrodes for the electrochemical regeneration of co-enzyme in biochemical, microbiological or biochemical processes as the anode in biochemical fuel cells or for analysis in systems utilizing co-enzyme-dependent enzyme.