On/Off Switchable Sequential Light-Harvesting Systems Based on Controllable Protein Nanosheets for Regulation of Photocatalysis

A controllable protein nanostructures-based On/Off switchable artificial light-harvesting system (LHS) with sequential multistep energy transfer and photocatalysis was reported herein for mimicking the natural LHS in both structure and function. Single-layered protein nanosheets were first constructed via a reversible covalent self-assembly strategy using cricoid stable protein one (SP1) as building blocks to realize an ordered arrangement of pigments. Fluorescent chromophores like carbon dots (CDs) can be precisely distributed on the protein nanosheets superficially via electrostatic interactions and make the ratio between donors and acceptors adjustable. After being anchored with a photocatalysis center (eosin-5-isothiocyanate, EY), the constructed LHS could sequentially transfer energy between two kinds of chromophores (CD1 and CD2), and further transfer to EY center with a high efficiency of 84%. Interestingly, the Forster resonance energy transfer (FRET) process of our LHS could be reversibly On/Off switched by the redox regulated assembly and disassembly of SP1 building blocks. Moreover, the LHS has been further proved to promote the yield of a model cross-coupling hydrogen evolution reaction and regulate the process of the reaction with the FRET process On/Off state.

Automated summary

A controllable protein nanostructures-based On/Off switchable artificial light-harvesting system with sequential multistep energy transfer and photocatalysis was reported, mimicking the natural system in structure and function. Single-layered protein nanosheets were constructed with an ordered arrangement of pigments, and fluorescent chromophores were distributed on the nanosheets via electrostatic interactions. The system achieved sequential energy transfer and high-efficiency photocatalysis. The catalytic process could be regulated by an On/Off switch.