A multifunctional cucurbit[6]uril-based supramolecular assembly for fluorescence sensing of TNP and Ba2+ and information encryption

Both nitroaromatic compounds (NACs) and heavy metal ions are accumulative high-risk environmental pollutants, so high-sensitivity detection of these environment pollutants is necessary. In this work, a cucurbit[6]uril (CB[6]) based luminescent supramolecular assembly [Na2K2(CB[6])2(DMF)2(ANS)(H2O)4](1) (CB[6] = cucurbit[6]uril, ANS2- = 8-Aminonaphthalene-1,3,6-trisulfonic acid ion) has been synthesized under solvothermal conditions, using ANS2- as a structural inducer. Performance studies have shown that 1 exhibits excellent chemical stability and easy regeneration ability. It can highly selective sensing of 2,4,6-trinitrophenol (TNP) through fluorescence quenching with a strong quenching constant (Ksv = 2.58 × 104 M-1). Additionally, the fluorescence emission of 1 can be effectively enhanced with Ba2+ in aqueous solution (Ksv = 5.57 × 103 M-1). More impressively, Ba2+@1 was successfully used as anti-counterfeiting fluorescent ink functional material with strong information encryption function. This work illustrates the application prospects of luminescent CB[6]-based supramolecular assembly in environmental pollutants detection and information anti-counterfeiting for the first time, which extends the multifunctional application scope of CB[6]-based supramolecular assembly.