Thioacetal modified phenanthroimidazole as fluorescence probe for rapid and sensitive detection of Hg2+ in aqueous solution assisted by surfactant

A novel fluorescence probe PISOH comprising phenanthroimidazole as a fluorophore and thioacetal as recognition unit is designed and synthesized. PISOH displays high selective turn-on fluorescence response toward Hg2+ with no interference from other metal cations, such as Cu2+, Ag+, Fe3+, Pb2+, etc. PISOH can be converted to the corresponding aldehyde PICHO in the presence of Hg2+, based on the Hg2+ promoted deprotection of thioacetal. Moreover, the fluorescence emission and sensing properties of PISOH can be modulated by surfactants in aqueous solution. PISOH exhibits a detection limit (LOD) of 1.16 nM for Hg2+ in aqueous Triton X-100 solution, much lower than that in DMF (LOD = 6.83 nM). The response time of PISOH for Hg2+ is around 1 min, suitable for rapid detection of Hg2+. Furthermore, the probe can be used to monitor Hg2+ effectively in living cells by fluorescence imaging. This work represents a novel and simple strategy for sensing of Hg2+ in pure water by using commercially available surfactants to solubilize fluorescent probe. (C) 2018 Elsevier B.V. All rights reserved.