Laponite cascade assembly activated reversible multicolor luminescence supramolecular hydrogel with near-infrared emission

Photo-responsive supramolecular assembly especially supramolecular hydrogels with tunable luminescence show a promising application potential in writable information recording and display materials. Herein, we report photo-responsive reversible multicolor supramolecular hydrogel with near-infrared emission, which is constructed by cucurbit[7]uril (CB[7]), cyanostilbene derivative (DAC) and Laponite XLG (LP) via supramolecular cascade assembly. Compared with the free guest molecule DAC, the confinement of macrocycle CB[7] achieve effective near-infrared fluorescence in the aqueous phase from scratch, and the subsequent cascade assembly with LP further restrict the molecular rotation of the DAC, which not only result in a substantial enhancement of the fluorescence intensity, but is also endowed with light-controlled fluorescence on/off both in the solution and hydrogel states. Further, 8‑hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt (HPTS) is introduced in the cascade assembly to fabricated photo-controllable reversible multicolor luminescence supramolecular hydrogel between red and green induced by Förster resonance energy transfer, which is successfully employed in reversible multiple information encryption. Photo-controllable multicolor supramolecular hydrogel switch was constructed by macrocycle cucurbit[7]uril, cyanostilbene derivative, Laponite and green fluorescent dye cascade assembly, exhibiting reversible multicolor luminescence between red and green for successful application in writable and self-erasing dynamic anti-counterfeiting.