Tuning the amphiphilicity of terpyridine-based fluorescent probe in water: Assembly and disassembly-controlled H g2+ sensing, removal, and adsorption of H2S

A water-soluble terpyridine-based cationic fluorescent probe ( SP - TPy ) was synthesized, which emerged with pH-dependent amphiphilicity, resulting in self-assembly and disassembly in aqueous media with the aggregation-induced emission (AIE) property. In neutral water (pH 7.4), a moderate sensing response to Hg 2+ ions was given by the self-assembly of SP - TPy . However, in acidic aqueous media, the monomer of SP - TPy not only appeared to be highly selective and sensitive for Hg 2+ ions, but also displayed highly efficient removal of Hg 2+ ions from solution by rapid precipitation, which was attributed to the coordination-triggered reassembly of SP - TPy . The removal efficiency of SP-TPy f or Hg 2+ was found to be over 99%. Further study indicated that the precipitates were composed of various polyhedral porous frameworks, a property that was further used to adsorb H 2 S gas to form HgS complexes with higher uptake capacities. In addition, SP - TPy can be efficiently regenerated and recycled using a simple treatment with acidic water after adsorption of the H 2 S gas.