Electrochemical Oxidation of NADH at Highly Boron-Doped Diamond Electrodes

Abstract

Conductive boron-doped chemical vapor-deposited diamond thin films, already known to have superior properties for general electroanalysis, including low background current and a wide potential window, are here shown to have additional advantages with respect to electrochemical oxidation of nicotinamide adenine dinucleotide (NADH), including high resistance to deactivation and insensitivity to dissolved oxygen. Cyclic voltammetry, amperometry, and the rotating disk electrode technique were used to study the reaction in neutral pH solution. Highly reproducible cyclic voltammograms for NADH oxidation were obtained at as-deposited diamond electrodes. The response was stable over several months of storage in ambient air, in contrast to glassy carbon electrodes, which deactivated within 1 h. The diamond electrode exhibited very high sensitivity for NADH, with an amperometric detection limit of 10 nM (S/N = 7). The response remained stable, even in the very low concentration range, for several months. In addition, interference effects due to ascorbic acid were minimal when the concentrations of NADH and ascorbic acid were comparable. An NADH-mediated dehydrogenese-based ethanol biosensor incorporating an unmodified diamond electrode is demonstrated. The present results indicate that diamond is a useful electrode material for the analytical detection of NADH, making it attractive for use in sensors based on enzyme-catalyzed reactions involving NADH as a cofactor.

Electrochemical oxidation of dihydronicotinamide adenine dinucleotide (NADH): comparison of highly oriented pyrolytic graphite (HOPG) and polycrystalline boron-doped diamond (pBDD) electrodes

“…The mechanism of NADH oxidation has been studied extensively by Moiroux and Elving [2][3][4][5] and it is well established that at neutral pH, NADH undergoes a two-electron one-proton oxidation process of the ECE (electron transfer-chemical step-electron transfer) type: (1) (2) (3) A wide range of carbon electrode materials have received considerable attention for NADH electro-oxidation, including glassy carbon, 4,6 carbon paste, 7 carbon nanotubes, 8,9 graphene 10 and graphene composites, [11][12][13] pyrolytic graphite 14 and boron-doped diamond. 15 The study of NADH oxidation on bare carbon electrode surfaces is non-trivial. 16 Relatively high overpotentials are often required and, furthermore, the oxidation products of NADH, particularly NAD + tend to adsorb strongly and foul surfaces quickly.…”

“…19,20 However, studies of unmodified electrodes are valuable both to provide a benchmark and to seek the optimal electrode format. The electrochemistry of NADH at conducting diamond has received attention, but the focus has mainly been on hydrogen-terminated diamond, 15,21 with oxygen terminated diamond 14 receiving only scant attention. Despite its importance as a well-defined model surface for sp 2 carbon, there are no reports of NADH oxidation at highly oriented pyrolytic graphite (HOPG) electrodes.…”

Determinação simultânea de NADH e ácido ascórbico usando voltametria de onda quadrada com eletrodo de carbono vítreo e calibração multivariada

“…Alguns eletrodos modificados conseguem resolver o problema da interferência eletroquímica na determinação destes compostos, entretanto, este aumento na seletividade é acompanhado por uma grande diminuição na sensibilidade. Em um dos trabalhos citados da literatura [6], um eletrodo de diamante dopado com boro muito sensível é utilizado para a determinação do NADH e ácido ascórbico. O potencial de oxidação do ácido ascórbico e do NADH neste eletrodo difere por 200mV, sendo que mesmo esta diferença de potenciais de pico não permite que haja uma resolução adequada dos picos voltamétricos.…”

Dehydrogenation studies of dihydronicotinamide adenine dinucleotide (NADH) with methylene blue in the presence of the copper hexcyanoferrate(II) complex and light

“…The oxidized and reduced form of NAD + (and NADP) are shown in Figure 1. Dehydrogenation studies of NADH are of interest, and some reports are available in chemical literature [23][24][25][26][27][28][29][30][31]. However, no reports are available on the dehydrogenation of NADH in presence of possible prebiotic photosensitizers.…”