Work

Semiartificial Photosynthetic Nanoreactors for H2 Generation

Year: 2024

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide A relatively unexplored energy source in synthetic cells is transmembrane electron transport, which like proton and ion transport can be light driven. Here, synthetic cells, called nanoreactors, are engineered for compartmentalized, semiartificial photosynthetic H 2 production by a Clostridium beijerinckii [FeFe]-hydrogenase (H 2 ase). Transmembrane electron transfer into the nanoreactor was enabled by MtrCAB, a multiheme transmembrane protein from Shewanella oneidensis MR-1. On illumination, graphitic nitrogen-doped carbon dots (g-N-CDs) outside the nanoreactor generated and delivered photoenergized electrons to MtrCAB, which transferred these electrons to encapsulated H 2 ase without requiring redox mediators. Compartmentalized, light-driven H 2 production was observed with a turnover frequency (TOF H2ase ) of 467 ± 64 h –1 determined in the first 2 h. Addition of the redox mediator methyl viologen (MV) increased TOF H2ase to 880 ± 154 h –1 . We hypothesize that the energetically “uphill” electron transfer step from MtrCAB to H 2 ase ultimately limits the catalytic rate. These nanoreactors provide a scaffold to compartmentalize redox half reactions in semiartificial photosynthesis and inform on the engineering of nanoparticle–microbe hybrid systems for solar-to-chemical conversion.

Source: Journal of the American Chemical Society

DOI: 10.1021/jacs.4c12311