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This study demonstrates a novel method to quantify selective (1,4-NADH) and unselective products (1,2- and 1,6-NADH) in NADH regeneration using combined UV-Vis spectroscopy and biological assays.

This study shows the importance of resolving catalytic performance in the regeneration of the reduced form of nicotinamide adenine dinucleotide (NADH) through activity measurements based on NAD+ conversion and the closure of mass balance via byproduct quantification. This approach is applied to assess the performance of supported platinum catalysts with varying points of zero charge, utilizing H2 as a reductant. It was found that Pt/SiO2, which exhibits a net negative charge under the reaction conditions, outperforms the neutral Pt/C and positively charged Pt/MgO because of the favorable electrostatic attraction between the catalyst surface and positively charged (+1) nicotinamide ring. NMR spectroscopy identifies side-products formed during NAD+ hydrogenation.

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The use of electric field represents a promising strategy to overcome the existent challenges in synthesizing metal nanoparticles. A facile and clean method for the preparation of water-soluble metal nanoparticles with a narrow particle distribution is reported here based on the electric-field-driven phase inversion procedure. Bioderived chitosan was used to stabilize the metal nanoparticles and formic acid was employed as both a solvent (for the polymer) and a reductant (for the metal). The electric field has been characterized to modify the hydrogen bonds of the chitosan and promote the stabilization and reduction of metal nanoparticles. Taking silver as an example, the nanoparticles obtained lay in the range of 2-6 nm with a mean size of 3.4 nm. The produced chitosan/Ag nanocomposites can be used in homogenous (water-soluble) form for catalysis and heterogeneous form (as a solid film) for antibiosis. Exceptional performance in the selective regeneration of cofactor NADH (TOF = 582 h -1 ) and an improved antibacterial performance were attained. Successful preparation of metallic Cu, Au and Pt nanoparticles (~1-2 nm) confirms the universality of this method for synthesizing functional nanomaterials with various potential applications.