Water-soluble host-guest fluorescent systems based on fluorophores and cucurbiturils with AIE or ACQ effects

Tetraphenylethene (TPE) and pyrene as typical aggregation induced emission (AIE) and aggregation caused emission quenching (ACQ) functional groups were utilized to design and synthesize water-soluble fluorescent molecules. Through a self-assembly process with cucurbituril hosts, a completed opposite fluorescence response was observed for TPE and pyrene based fluorescent molecules. The assembly processes were verified by 1H NMR, UV–Vis, fluorescence spectroscopy. The mechanism was then studied and the aggregation-induced fluorescence change was concluded. These new host-guest supramolecular fluorescence systems can be used as fluorescence sensors or switches, expanding the application of fluorescence systems in biological imaging.