Benzothiadiazole-based water-soluble macrocycle: Synthesis, aggregation-induced emission and selective detection of spermine

Reported here is the synthesis of a new macrocycle bearing anionic carboxylate groups with water-soluble aggregation-induced emission (AIE). The water-soluble macrocycle without typical AIE luminogens is constructed based on the building block of benzothiadiazole. It exhibits a remarkable AIE effect. This water-soluble macrocycle can selectively bind different types of biogenic amines in aqueous media with the tightest binding towards spermine. The fluorescence enhancement induced by supramolecular encapsulation is used to detect spermine.