Artificial Light-Harvesting System with Three-Step Cascade Energy Transfer Process for Full-Color Luminescence Modulation

The artificial light-harvesting system (LHS) based on the cascade fluorescence resonance energy transfer (FRET) mechanism has ability to widely regulate the luminescent performance, however, it still faces significant challenges to achieve full-color luminescent regulation covering the entire visible spectrum in a single LHS system. In this study, we designed and constructed an artificial LHS with a three-step cascade energy transfer mechanism, achieving effective emission of white light and multicolor fluorescence within the visible light range. A cationic 6-bromobenzo[de]isochromene-1,3-dione derivative (BNI) was prepared, which was able to generate a supramolecular complex with sulfobutylether-β-cyclodextrin (SBE-β-CD) via electrostatic interactions. Given that this complex has excellent dark blue fluorescence performance, it was selected as the energy donor and sequentially participated in FRET process with commercial dyes Fluorescein (Flu), Rhodamine B (RhB) and Sulforhodamine 101 (SR101), thereby constructing an artificial LHS with three-step sequential energy transfer. By precisely regulating the ratios of acceptor molecules, multicolor fluorescence emissions ranging from blue to red bands and white light emission were achieved. Ultimately, the synthesized supramolecular LHS was effectively utilized in the development of multicolor fluorescent light-emitting devices and demonstrated its potential application in information storage.