Photocatalytic Biohybrid Vesicles

Semiartificial photosynthesis presents an attractive route to overcome limitations of natural photosynthesis for sustainable chemicals production. Synthetic materials are combined with biological molecules, forming biohybrid systems, that provide unique opportunities to innovate new solar-to-chemical pathways. There are further advantages if the biohybrids confine specific processes to different spatial locations. Such behavior is a defining feature of natural photosynthesis and it is mimicked in the photocatalytic biohybrid vesicles discussed in this Review. A nonleaky membrane comprised of amphiphilic molecules defines the wall of the reactor vesicle. Light-driven directional transfer of electrons and/or ions across the vesicle membrane generates an (electro)chemical gradient, a form of energy storage, that is subsequently harnessed for chemical synthesis. In such systems, nonproductive backreactions are avoided, reactants can be concentrated to favor their conversion, and reaction intermediates can be channeled through the desired pathway. This Review introduces natural photosynthesis and vesicles as biohybrid reaction containers. Different approaches to achieving light-driven charge transfer across vesicle membranes are reviewed, and state-of-the-art strategies for delivering light-driven chemical production are systematically summarized for this interdisciplinary field. Finally, key scientific problems and bottlenecks to the development of photocatalytic biohybrid vesicles are defined to provide insights for driving forward future research.