A cucurbit[6]uril-based fluorescence supramolecular assembly for information encryption and visualization detection of nitro compounds and antibiotics.

A novel CB[6]-based supramolecular assembly [K(ANS)(CB[6])2(DMF)2(H2O)0.5] (1) (CB[6] = cucurbit[6]uril, ANS- = 8-amino-1-naphthalene sulfonic acid ion) was successfully synthesized under solvothermal condition. Performance studies have shown that 1 exhibited excellent chemical stability and recycling performance. Meanwhile, 1 exhibited remarkable potential as a fluorescence sensor for the detection of 2,4,6-trinitrophenol (TNP), 4-nitrophenol (4-NP), and rifampicin (RFP) in both aqueous environments and practical samples. This sensing capability is achieved through fluorescence quenching, which offers fast response times and exceptional sensitivity, with detection limits of 0.19 µM for both TNP and 4-NP, and 0.21 µM for RFP. Even more remarkably, an anti-counterfeiting ink based on 1 and a portable test hydrogel were devised for encrypting information and visually detecting using a smartphone application. This work has the potential to expand the utilization of CB[6]-based materials in optical applications.

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.