NEW AMPEROMETRIC DEHYDROGENASE ELECTRODES BASED ON ELECTROCATALYTIC NADH-OXIDATION AT POLY(METHYLENE BLUE)-MODIFIED ELECTRODES

Poly(methylene blue) (PMB)-modified electrodes show excellent properties for the electrocatalytic oxidation of NADH concerning the optimal working potential of 0 to 100 mV (vs. SCE) and their operation stability. By means of dehydrogenases entrapped within a Nafion film on top of the PMB layer, new amperometric biosensors for glucose, lactate, malate. and ethanol could be obtained with improved integration of the enzyme and the electrocatalyst directly on the electrode surface. Coentrapment of the negatively charged NAD(+) within the negatively charged Nafion polyelectrolyte leads to reagentless dehydrogenase electrodes for one-shot or short-term applications.