Closing the Gap for Electronic Short-Circuiting: Photosystem I Mixed Monolayers Enable Improved Anisotropic Electron Flow in Biophotovoltaic Devices

Well-defined assemblies of photosynthetic protein complexes are required for an optimal performance of semi-artificial energy conversion devices, capable of providing unidirectional electron flow when light-harvesting proteins are interfaced with electrode surfaces. We present mixed photosystem I (PSI) monolayers constituted of native cyanobacterial PSI trimers in combination with isolated PSI monomers from the same organism. The resulting compact arrangement ensures a high density of photoactive protein complexes per unit area, providing the basis to effectively minimize short-circuiting processes that typically limit the performance of PSI-based bioelectrodes. The PSI film is further interfaced with redox polymers for optimal electron transfer, enabling highly efficient light-induced photocurrent generation. Coupling of the photocathode with a [NiFeSe]-hydrogenase confirms the possibility to realize light-induced H-2 evolution.

Automated summary

A well-defined assembly of PSI complexes can optimize the performance of semi-artificial energy conversion devices, reducing short-circuiting processes. By combining native PSI trimers and monomers from the same organism, a high density of photoactive proteins is achieved, enabling efficient electron transfer and light-induced photocurrent generation. Coupling the photocathode with a [NiFeSe]-hydrogenase confirms the potential for light-induced H-2 evolution.