AIE gel exhibiting continuous gradient fluorescence based on a polar‐responsive AIE‐gen

Abstract Traditional multicolor fluorescent hydrogels are generated through the assembly of discrete fluorescent hydrogels, which is not a complete integration much distinct from living organisms. On the basis of aggregation‐induced emission (AIE), a special solvent polar‐responsive AIE molecule possessing a twisted intramolecular charge transfer (TICT) effect was noticed. By incorporating it into the gel network, an AIE gel that displays continuous gradient fluorescence was fabricated. First, hydrogel A containing the solvent polar‐responsive AIE‐gen was prepared to show orange fluorescence. After soaking in the organic solvents, the fluorescence color transition of hydrogel A ranging from orange to green occurred when being immersed in high‐polarity organic solvents ascribed to the embedded AIE‐gen owning TICT effect. Then, hydrogel A was successively lifted up from organic solvents. Due to the different immersion time of each section for the hydrogel, the polarity difference occurred. Then, the produced gel B showed continuous gradient fluorescence ranging from orange to green under the irradiation of UV light.