The role of adsorption in the initial one-electron electrochemical reduction of nicotinamide adenine dinucleotide (NAD+)

Unexplored interactions between pyrroloquinoline quinone and β-nicotinamide adenine dinucleotide

“…7B and C are almost unchanged in position except for the current tending to limiting values with increasing [NAD + ]. The newformed waves are unlikely to result from the dimerization of NAD + either, because the dimerization of NAD + involves the reduction of NAD + into the NAD Å radical, which occurs only at E < À1.2 V [43]. Accordingly, we postulate that PQQ can form complexes with NAD + through (22), and the adduct O can accept electrons at potentials more positive than the formal potential for PQQ/PQQH 2 via a one-electron-transfer process as proposed in (23) (E 0 0 o : $ 0 V; DE p $ 60 mV according to Fig.…”

“…application of the Laplace transform to (30) and (43) and the related boundary conditions, (41) and (42), leads to (44).…”

Electrochemical reduction of NAD+ on a polycrystalline gold electrode

“…7b, a mean value of the apparent heterogeneous electron-transfer rate constant was calculated, k = (3 ± 2) × 10 −2 cm s −1 . Bresnahan and Elving [3] reported roughly an order of magnitude higher value (0.1 cm s −1 ) at −1.123 V versus SCE and pH 9.1 on a mercury electrode, assuming that NAD + is reduced only to NAD 2 (oneelectron process). However, they emphasized that the calculated value is approximate due to uncertainty in determining the value from their reported experimental data.…”

“…modified) high-hydrogen-evolution-overpotential electrodes, such as mercury [1][2][3][4][5][6][7][8][9][10] and various carbon materials [11]. It has been shown [2][3][4][5] that the reduction of NAD + on Hg proceeds by the transfer of one electron to the pyridinium ring, but at significantly high cathodic overpotentials (ca. −1.2 V versus SCE at pH 7), followed by fast radical coupling to form an enzymatically inactive dimer NAD 2 (see Scheme 1).…”

A simple, effective NADH sensor constructed with phenothiazine via AFM tip-induced oxidative polymerization

“…However, they suffer from electrontransfer barriers at most electrodes as applied in biofuel cells [10]. Phenothiazines, such as thionine (TH), toluidine blue (TB) and methylene blue (MB), can reduce the overvoltage for NAD + / NADH in solution or when surface-bound [5,11].…”