Direct electrochemical regeneration of the enzymatic cofactor 1,4-NADH employing nano-patterned glassy carbon/Pt and glassy carbon/Ni electrodes

A glassy carbon electrode surface was patterned with electrochemically deposited platinum and nickel nano-particles, with the aim of increasing the electrode efficiency in the process of in situ electrochemical regeneration of enzymatically active 1,4-NADH from NAD(+), in a batch electrochemical reactor. The role of Pt and Ni was to provide 'active' adsorbed hydrogen (Pt-H-ads or Ni-H-ads) for the fast protonation of electrochemically formed NAD-radical. The effect of nano-particle size, surface coverage, and the electrode potential on the percentage of 1,4-NADH recovered from NAD(+) was investigated. It was demonstrated that up to a 100% recovery of 1,4-NADH from NAD(+) was possible on the produced electrodes at relatively low electrode potentials, making them excellent candidates for regeneration of 1,4-NADH in industrial bioreactors. (c) 2012 Elsevier B.V. All rights reserved.