Protein‐Mediated Biosynthesis of Semiconductor Nanocrystals for Photocatalytic NAD(P)H Regeneration and Chiral Amine Production

The use of predesigned bioengineered proteins for self‐grown nanomaterials is a promising strategy that opens new scientific directions for biotic‐abiotic nano‐bio hybrid configurations. The unique properties of nanomaterials can alter the original biological paradigm to allow novel metabolic routes or new activation triggers. In this work, we present a synthetic methodology for self‐grown cadmium sulfide quantum dots in a 12‐mer bioengineered stable protein 1 under ambient conditions. The sized controlled crystalline QDs are characterized and utilized for NADPH regeneration that is in turn used for the activation of the imine reductase enzyme. The presented nano‐bio hybrid system enables the production of a single enantiomeric product that is required for the pharmaceutical industry. Our designed system presents superior activity and can continuously operate for at least 22 hrs with 82 % conversion efficiency. The obtained results may lay the foundations for future nano‐bio hybrid systems that can operate both in vitro and in vivo. A size‐controlled, homogeneous, and ordered biosynthesis of CdS NPs in a bioengineered protein cavity is presented. The formed nano‐bio hybrid facilitates outstanding photocatalytic NADPH regeneration that can be utilized for the photo‐induced activation of redox enzymes. The nano‐bio hybrid presented superior long‐term stereoselective production of a chiral amine that is essential for the pharmaceutical industry.