Coupling plasmonic catalysis and nanocrystal growth through cyclic regeneration of NADH

Abstract

In a typical colloidal synthesis, the molecules of the reducing agent are irreversibly oxidized during nanocrystal growth. Such a scenario is of questionable sustainability when confronted with naturally occurring processes...

Photocatalytic NADH Regeneration Employing Au–Pd Core–Shell Nanoparticles: Plasmonic Modulation of Underlying Reaction Kinetics

“…In the depicted mechanism (Figure a), moderate concentration (1 mM) of NAD + attributes to a higher possibility of adsorption of both the substrates on adjacent locations so that it can produce reduced NADH and oxidized TEOA* via a direct electron transfer. The standard redox potentials of NAD + and TEOA are −0.32 and +1.07 V, respectively, creating a possibility of a spontaneous NADH regeneration, responsible for the direct electron transfer from TEOA to NAD + in dark conditions. , A higher concentration of NAD + can inhibit the redox process by occupying both the adsorption sites of NAD + and TEOA. The obtained results can be validated by the bimolecular Langmuir–Hinshelwood (L-H) model, where adsorption interaction (or sites) is the same for both the reactants (competitive adsorption). , The obtained trend can be interpreted with the following eq , where [A] and [B] are the concentration of the substrates (NAD + and TEOA, respectively), K eff is the catalytic rate constant, and a is the equilibrium constant for substrate adsorption. …”

“…To increase the domain of these bimetallic composites in photocatalysis, we have explored Au–Pd core–shell nanoparticles (Au–Pd CS NPs) to regenerate NADH from its oxidized form β-NAD + in a colloidal solution of this bimetallic composite. Previously, few reports have successfully demonstrated NADH regeneration using immobilized Au–Pd nanorods over cellulose fibers and agarose matrix. , NADH is a coenzyme (cofactor) molecule used as a hydride source by almost 80% of existing oxidoreductase enzymes. These enzymes have many applications, including enzyme catalysis to synthesize chemicals and pharmaceuticals, biodegradation, and detoxification. , Despite being a mainstream coenzyme, NADH has relatively less utilization in industries due to its high cost.…”