Electrocatalytic oxidation of NADH at mesoporous carbon modified electrodes

The electrochemical oxidation of β-nicotinamine adenine dinucleotide (NADH) was investigated at a glassy carbon electrode modified with carbon mesoporous materials (CMM). Due to the large surface area and electro-catalytic properties of CMM, the overpotential of the electrodes toward the oxidation of NADH is decreased by 595 mV in aqueous solution at neutral pH. The anodic peak currents increase steadily with the concentration of NADH in the range from 2 μM to 1.1 mM, the detection limit being 1.0 μM at pH 7.2 and a potential of +0.3 V vs. SCE. The apparent Michaelis-Menten constant is ∼21.5 μM. The results enable NADH to be sensed at a low potential and are promising with respect to the design of dehydrogenase-based amperometric biosensors.