Amperometric determination of NADH at a Nile blue/ordered mesoporous carbon composite electrode

A novel amperometric NADH sensor was presented based on a Nile blue A (NB)/ordered mesoporous carbon (OMC) composite (NB/OMC) electrode. Cyclic voltammetric tests revealed the NB/OMC displayed a new well defined redox couple in the potential range of −250 to 50 mV in pH 6.85 phosphate buffer. Interestingly, we found that only the new redox couple exhibited significant catalytic activity towards the oxidation of NADH. Under a lower operation potential of −0.1 V, NADH could be linearly detected up to 350 μM with an extremely lower detection limit of 1.2 μM (S/N = 3).