Microbial/enzymatic light-induced NADPH regeneration electrochemical cells for continuous electrosynthesis of...

Electrosynthesis is an emerging research direction for greener and more efficient chemical synthesis. Although heterogeneous catalysis efficiency can be improved by tuning electrode surface properties, electrocatalysts frequently fall short of producing chiral molecules with high purity and minimized side reactions. Enzymes are superior catalysts with lower activation barriers. These catalysts, developed through evolution, enable high selectivity and specificity, which are essential for many industrial and pharmaceutical processes. Thus, electronically coupling enzymes or bacteria with electrodes can drive efficient chemical synthesis while ensuring the required selectivity. Here, we used an enzymatic cascade or engineered bacteria for the conversion of 2-methylpyrroline to (R)-2-methylpyrrolidine by isolating or overexpressing imine reductase (IRED), respectively. We further show that coupling the bioelectrocatalytic process with a CdS/NiO-based photoanode enables light-driven, bias-free photo(bio)electrochemical cell activation. The developed platform is versatile and adaptable for any process requiring NADPH-dependent enzymes, in vivo or in vitro.