The in vitro synergistic denaturation effect of heat and surfactant on photosystem I isolated from Arthrospira Platensis

Improving Photostability of Photosystem I-Based Nanodevice by Plasmonic Interactions with Planar Silver Nanostructures

One of the crucial challenges for science is the development of alternative pollution-free and renewable energy sources. One of the most promising inexhaustible sources of energy is solar energy, and in this field, solar fuel cells employing naturally evolved solar energy converting biocomplexes—photosynthetic reaction centers, such as photosystem I—are of growing interest due to their highly efficient photo-powered operation, resulting in the production of chemical potential, enabling synthesis of simple fuels. However, application of the biomolecules in such a context is strongly limited by the progressing photobleaching thereof during illumination. In the current work, we investigated the excitation wavelength dependence of the photosystem I photodamage dynamics. Moreover, we aimed to correlate the PSI–LHCI photostability dependence on the excitation wavelength with significant (ca. 50-fold) plasmonic enhancement of fluorescence due to the utilization of planar metallic nanostructure as a substrate. Finally, we present a rational approach for the significant improvement in the photostability of PSI in anoxic conditions. We find that photobleaching rates for 5 min long blue excitation are reduced from nearly 100% to 20% and 70% for substrates of bare glass and plasmonically active substrate, respectively. Our results pave promising ways for optimization of the biomimetic solar fuel cells due to synergy of the plasmon-induced absorption enhancement together with improved photostability of the molecular machinery of the solar-to-fuel conversion.

Putting Photosystem I to Work: Truly Green Energy

Meeting growing energy demands sustainably is one of the greatest challenges facing the world. The sun strikes the Earth with sufficient energy in 1.5 h to meet annual world energy demands, likely making solar energy conversion part of future sustainable energy production plans. Photosynthetic organisms have been evolving solar energy utilization strategies for nearly 3.5 billion years, making reaction centers including the remarkably stable Photosystem I (PSI) especially interesting for biophotovoltaic device integration. Although these biohybrid devices have steadily improved, their output remains low compared with traditional photovoltaics. We discuss strategies and methods to improve PSI-based biophotovoltaics, focusing on PSI-surface interaction enhancement, electrolytes, and light-harvesting enhancement capabilities. Desirable features and current drawbacks to PSI-based devices are also discussed.