Dynamic information encryption via fluorescent hydrogels based on Perylene Diimide crosslinker

Fluorescent hydrogels were considered a superior platform for developing functional materials in multiple application areas to date. The design and application of aggregation-caused quenching (ACQ) based fluorophores in fluorescent hydrogels are fundamentally constrained by their inherent aggregation-caused quenching behavior. Herein, we report the first fluorescent hydrogel utilizing a perylene diimide (PDIC) as a covalent crosslinker, overcoming inherent ACQ limitations to enable multidimensional information encryption. The hydrogel exhibited reversible Fe 3+ -responsive fluorescence switching and pronounced differential swelling/deformation responses to pH 8 stimulation. Fe 3+ was used for the first information encryption input. Subsequently, exposure to Ca 2+ or alkaline conditions (pH 8) induces a shape deformation that enables secondary information encryption. This strategy establishes a new paradigm for utilizing ACQ fluorophores in functional hydrogels, promoting the development of more ACQ-based fluorescent hydrogels for anti-counterfeiting and secure data storage applications.