Self-Assembled Quadruplex-Inspired Peptide Nucleic Acid Tetramer for Artificial Photosynthesis

Artificial photosynthesis serves as a promising approach to exploit inexhaustible sunlight energy by converting it into chemical energy. However, the limited availability of stable systems with precise and coordinated organization of both an energy harvesting and a catalytic moiety hinders its practical application. Herein, for the first time, we demonstrate the utilization of self-assembled G-quadruplex inspired peptide nucleic acid (PNA)-tetramer (Fmoc-G-PNA tetramer) as a template for an artificial photosynthesis system. Our approach involves integrating a ruthenium light harvesting antenna and a platinum catalyst on the Fmoc-G-PNA tetramer. In the presence of the Fmoc-G-PNA tetramer, a 3-fold increase in the rate of NAD⁺ reduction to NADH is observed, compared to bare ruthenium complex and catalyst. Also, due to direct electron transfer, no external mediators are necessary, and the catalytic system is recyclable. This newly designed, easily fabricated Fmoc-G-PNA tetramer architecture could be a promising candidate for the design of bioinspired light harvesting systems and photoelectric devices.