1.D.301. The Photosynthetic Membrane-like Light-driven Cation Transport (PMLCT) Family
The selective uphill and downhill movement of protons in and out of photosynthetic membrane, enabled by ion pumps and ion channels, is key to photosynthesis. Reproducing the functions of photosynthetic membranes in artificial systems would be useful. Nie et al. 2024 created visible-light-harvesting nanofluidic channels which experimentally demonstrate the ion translocation functions of photosynthetic membranes. A molecular junction consisting of photosensitive ruthenium complexes linked to TiO2 electron acceptors forms the reaction centers in the nanofluidic channels. The visible-light-triggered vectorial electron injection into TiO2 establishes a difference in transmembrane potential across the channels, which enables uphill transport of ions against a 5-fold concentration gradient. In addition, the asymmetric charge distribution across the channels enables the unidirectional downhill movement of ions, demonstrating an ion rectification effect with a ratio of 18:1. Thus, this system mimics both the uphill and downhill ion translocation functions of photosynthetic membranes, which lays a foundation for nanofluidic energy conversion (Nie et al. 2024).