A reusable thioether-rich crown-based fluorescent sensor for the detection and removal of mercuric ions

Based on the thioether-rich crown receptor, we describe a naphthalimide based bifunctional fluorescent sensor (FS-G) for simultaneous detection and separation of trace Hg(2+) in water. FS-G exhibited excellent selectivity toward Hg(2+) in aqueous environment and showed 5-fold increase in fluorescence emission intensity upon the addition of Hg(2+). A good linearity was observed between the fluorescence enhancement and the dose of Hg(2+) with a lower detection limit of 33.4ppb. Additionally, adsorption capacity of FS-G is 7.4mgg(-1). FS-G can be easily regenerated when treated with dimercaptosuccinic acid. These results indicate that FS-G has potential applications for detection and removal of trace Hg(2+) in water.