Synthesis and characterization of a new cucurbit[6]uril-based supramolecular framework and its application in water contaminants detection and anticounterfeiting applications

A novel supramolecular framework [Cd(QDS) 2 ]·(CB[6]) 2 ( 1 ) based on cucurbit[6]uril (CB[6]) and 8-hydroxyquinoline-5-sulfonic acid ion (QDS − ) was successfully synthesized under solvothermal conditions. The single crystal X-ray diffraction analyses indicated that the construction of this supramolecular framework is attributed to the non-covalent interactions between the QDS − and the outer surface of CB[6]. The performance study demonstrates that 1 exhibits a remarkable sensitivity and selectivity in detecting anions Cr 2 O 7 2− , MnO 4 − , furan antibiotics nitrofurantoin (NFT) and nitrofurazone (NFZ) through fluorescence quenching with the limit of detection (LOD) were 95, 89, 132, and 113 ppb, respectively. Meanwhile, due to the remarkable fluorescent properties of 1 , anti-counterfeiting marks were incorporated into the positioning boxes of quick response (QR) codes. The anticounterfeiting signs appear yellow in daylight while exhibit bright green fluorescence when excited at 365 nm. Furthermore, 1 also have been successfully applied to real samples with satisfactory results. These remarkable findings suggest that 1 hold promise as an effective fluorescent sensor.