Effects of adsorption, electrode material, and operational variables on the oxidation of dihydronicotinamide adenine dinucleotide at carbon electrodes

Abstract

The electrochemical oxidation of dihydronicotinamide adenine dinucleotide (NADH) was studied in buffered aqueous media (pH 7.0) by single and multiple sweep voltammetry and pulse (normal, differential, and derivative) techniques at rotating disk electrodes, and by single sweep voltammetry at stationary disk electrodes; two different kinds of glassy carbon and one type of pyrolytic graphite were used to prepare the electrodes. The

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

“…This behavior, and its comparison to the pBDD response and the behavior on a surface freshly prepared before each voltammagram (discussed below), is strongly indicative of the HOPG surface becoming blocked by NADH oxidation products, as found for other carbon electrode materials. 5,14 For comparison, CVs were run, for the same scan rates, at freshly polished pBDD or freshly cleaved HOPG prior to each CV. The results, shown in Figure 2 CVs on freshly cleaved surfaces showed well-defined peaks of much higher current density magnitude that scale reasonably with the square root of scan rate, as indicative of a diffusion-limited process.…”

“…As such, the development of robust methods of analysis for NADH is of considerable importance, with electrochemical methods proving particularly effective. 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.…”

Selective Detection of NADH with Neutral Red Functionalized Carbon Nanotube/Plasma-polymerized Film Composite Electrode

“…One problem is that direct oxidation of NADH generated by enzymatic reaction needs the high overvoltage (³1 V) at surface of bare electrode. 1 Typical solution to overcome is the utilization of nanomaterial carbon nanotube (CNT), which is considered to be formed by the folding of graphene layers into carbon cylinders 2 because of theirs excellent electron transfer properties and catalytic activities. 3 13 The CNT's excellent catalytic activity lowers its oxidative potential (<0.6 V) to avoid fouling problems e.g.…”

NADH Oxidation Using Carbonaceous Electrodes Modified with Dibenzo‐Dithia‐Diazapentacene

“…Thus, it was clearly established that for electrochemical oxidation of NADH to yield enzymatically active NAD it is necessary to use suitable redox mediators [3 ± 6] because direct oxidation of NADH at bare conventional electrode materials requires high overpotentials [7,8]. These high overpotentials may induce electrochemical interferences in a biosensor when analyzing real samples and cause loss of energy in a biofuel cell, and may also result in electrode fouling because of adsorption of NAD at the electrode surface or the formation of radical intermediates [1, 9 ± 12].…”