Poly(Flavin adenine dinucleotide, FAD) characterized by an additional polymer-type redox reaction is a highly effective electrocatalyst for NADH oxidation: operating at the lowest potentials reported for NADH transducers (0.00 V, pH 7.4), poly(FAD) is characterized by the electrochemical rate constant of 1.8 ± 0.6×10-3 cm/s, which is at the level of the NADH mass-transfer constant. Poly(FAD)-modified electrodes are characterized by the dramatically improved stability and, is the most advantageous NADH transducers for analytical chemistry[1].