An Integration Strategy to Develop Dual-State Luminophores with Tunable Spectra, Large Stokes Shift, and Activatable Fluorescence for High-Contrast Imaging

Abstract

Developing dual-state luminophores (DSLs) with strong fluorescence in both the monomer and aggregate states is urgently needed but remains a huge challenge because most current luminophores are either aggregation-induced emission or aggregation-caused quenching molecules. Moreover, limited by the structural conservation of the few existing DSLs, there are not enough response sites that can be used to customize various activatable fluorescent probes for specific molecular imaging. Herein, we engineered a general integration strategy for the fabrication of such DSLs with excellent photophysical properties. The DSLs, with their tunable spectra, a large Stokes shift (>170 nm), and achievable near-infrared (NIR) emission, show great potential for high-contrast imaging. Importantly, DSLs can be used as a universal platform for probe customization due to their activatable fluorescence through protection–deprotection of the phenolic hydroxyl group. Based on this, an NIR fluorescent probe DSL-Gal was developed for sensing of β-galactosidase in solutions, senescent cells, and liver metastases with high contrast, further confirming the superiority and universal feasibility of DSLs in probe design. The integration strategy may provide a novel approach for the generation of other DSLs and have great potential applications in bioimaging.