NADH Oxidation Catalyzed by Electropolymerized Azines on Carbon Nanotube Modified Electrodes

Abstract

Electropolymerizing azines on a carbon nanotube (CNT) modified electrode yields a high-surface area interface with excellent electrocatalytic activity towards NADH oxidation. Electrodeposition of poly(methylene green) (PMG) and poly(toluidine blue) (PTBO) on the carboxylated CNT-modified electrodes was achieved by cyclic voltammetry. The PMG-CNT interface demonstrates 5.0 mA cm À2 current density for NADH oxidation at 50 mV vs. Ag j AgCl in 20 mM NADH solution. The kinetics of NADH electrocatalysis were analyzed using a quantitative mass-transport-corrected model with NADH bulk concentration and applied potential as independent variables. This high-rate poly(azine)-CNT interface is potentially applicable to high-performance bioconversion, bioenergy and biosensors involving NADH-dependent dehydrogenases.

Facilitation of High-Rate NADH Electrocatalysis Using Electrochemically Activated Carbon Materials

“…Table 1 lists half-wave potentials for the materials considered after mass transfer correction. 28 As shown in Table 1 and Figure 4a, Act-GC shows lower half-wave potentials for NADH oxidation than Act-f CNT, indicating higher loading of quinones, consistent with higher loading and higher proportion of redox active group as discussed above. Considering these facts, it is likely that the activity of Act-GC is mainly attributed to the quinone groups, while either f CNT or Act-f CNT serves more as the high surface area material.…”

“…These activated carbon materials allow subsequent adsorption of the electrocatalyst methylene green (MG), forming a novel NADH-oxidizing interface. The activity of MG-f CNT toward NADH oxidation is higher than that of our previously reported poly(azine)-f CNT electrodes, 28 demonstrating an improved facilitation of NADH electrocatalysis.…”

New electrode architectures based on poly(methylene green) and functionalized carbon nanotubes: Characterization and application to detection of acetaminophen and pyridoxine

“…The best way to prepare films of electroactive polymer is by electropolymerisation of the redox-active monomer, as is the case of phenazine monomers [1]. Electropolymerised films of phenazines have been extensively used in electrochemical sensors and biosensors [2], poly (methylene green) (PMG) being mostly utilized for electrocatalysis of NAD + regeneration [3][4][5], and consequently for the development of biofuel cells based on NAD + -dependent dehydrogenase enzymes [6][7][8][9][10][11].…”

Enhanced Reduced Nicotinamide Adenine Dinucleotide electrocatalysis onto multi-walled carbon nanotubes-decorated gold nanoparticles and their use in hybrid biofuel cell

“…In this context, literature has reported different strategies toward the electrochemical regeneration of NAD + . Phenothiazine derivatives such as methylene green, methylene blue, and neutral red can efficiently oxidize NADH, even in their electropolymerized form [10][11][12][13]. Other materials such as metal oxides, poly(aniline), and enzymes have also been reported as efficient catalysts for the electrochemical regeneration of NAD + [14][15][16].…”