Direct regeneration of NADH on a ruthenium modified glassy carbon electrode

A kinetic study of NAD+ reduction on a ruthenium modified glassy carbon electrode

“…5(b). The same conclusion was obtained on the basis of chronocoulometric results done at various concentrations and potentials [14]. The corresponding concentration gradient representing the driving force for the surface mass flux, i.e.…”

“…This will be discussed in our subsequent paper [14], where it will be shown that our RuGC electrode is capable of producing a 96% yield of enzymatically active 1,4-NADH by the reduction of NAD þ at )1.2 V vs. SCE. In this paper, which presents our kinetic studies on reduction of NAD þ , it is rather important to notice that the reaction discussed proceeds not to the formation of the dimer NAD 2 , but further to NADH, with the exchange of two electrons and one hydrogen per one NAD þ molecule (Scheme 1).…”

“…The electron transfer occurs on a GC part of the RuGC surface, while the protonation occurs at the GCjRu interface boundary. Since the electrolysis of NAD þ at )1.2 V vs. SCE [14] resulted in the yield of 1,4-NADH of 96%, and since only one cathodic peak was observed in CV and DPV measurements discussed previously in the paper, the second electron step, which involves the transfer of an electron to an NAD-radical, is not energetically significantly different than the first electron-transfer step, which supports the above mechanistic scheme as a possible reaction mechanism. Also, besides enhanced electron and hydrogen transfer kinetics on the RuGC electrode, compared to GC, Pt, Au and some other non-modified electrodes, an additional possible reason for avoiding the dimer formation, which allows then for the formation of NADH, could also be that free NAD-radicals formed are separated one from the other by Ru sites (i.e.…”

“…In a forthcoming paper [14] we will report our results related to the investigations of the electrode surface morphology, interface charge distribution, and electrolysis (regeneration) of NADH in an electrochemical batch reactor using the newly developed RuGC electrode. As will be shown, the RuGC electrode is capable of reducing NAD þ directly to NADH at a very high yield (96%) of enzymatically active 1,4-NADH.…”

Electrochemical reduction of NAD+ on a polycrystalline gold electrode

“…trode surface with nano-islands of electrodeposited ruthenium, a very high yield (96%) of the enzymatically active 1,4-NADH can be formed by the direct reduction of NAD + [25,26].…”