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Updated: Mar 10, 2026

Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H2 Production in Aqueous Aerobic Conditions
Published on: October 5, 2019
Sunlight-Dependent Hydrogen Production by Photosensitizer/Hydrogenase Systems
David Adam1, Lisa Bösche1, Leonardo Castañeda-Losada2
1Department of Biology and Biotechnology, AG Photobiotechnology, Ruhr-University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.
Abstract:
We report a sustainable in vitro system for enzyme-based photohydrogen production. The [FeFe]-hydrogenase HydA1 from Chlamydomonas reinhardtii was tested for photohydrogen production as a proton-reducing catalyst in combination with eight different photosensitizers. Using the organic dye 5-carboxyeosin as a photosensitizer and plant-type ferredoxin PetF as an electron mediator, HydA1 achieves the highest light-driven turnover number (TONHydA1 ) yet reported for an enzyme-based in vitro system (2.9×106 mol(H2 ) mol(cat)-1 ) and a maximum turnover frequency (TOFHydA1 ) of 550 mol(H2 ) mol(HydA1)-1 s-1 . The system is fueled very effectively by ambient daylight and can be further simplified by using 5-carboxyeosin and HydA1 as a two-component photosensitizer/biocatalyst system without an additional redox mediator.
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