Transitioning Room-Temperature Phosphorescence from Solid States to Aqueous Phases via a Cyclic Peptide-Based Supramolecular Scaffold

Aqueous room-temperature phosphorescence (RTP) materials have garnered considerable attention for their significant potential across various applications such as bioimaging, sensing, and encryption. However, establishing a universally applicable method for achieving aqueous RTP remains a substantial challenge. Herein, we present a versatile supramolecular strategy to transition RTP from solid states to aqueous phases. By leveraging a cyclic peptide-based supramolecular scaffold, we have developed a noncovalent approach to molecularly disperse diverse organic phosphors within its rigid hydrophobic microdomain in water, yielding a series of aqueous RTP materials. Moreover, high-performance supramolecular phosphorescence resonance energy transfer (PRET) systems have been constructed. Through the facile co-assembly of a fluorescent acceptor with the existing RTP system, these PRET systems exhibit high energy transfer efficiencies (>80%), red-shifted afterglow emission (520-790 nm), ultralarge Stokes shifts (up to 450 nm), and improved photoluminescence quantum yields (6.1-30.7%). This study not only provides a general strategy for constructing aqueous RTP materials from existing phosphors, but also facilitates the creation of PRET systems featuring color-tunable afterglow emission.