Highly selective and sensitive detection of Hg by a novel fluorescent probe with dual recognition sites.

A novel thionocarbonate-coumarin-thiourea triad-based probe with dual recognition sites for sensing mercury (Hg) ion was developed. The synthesized probe possessed both fluorogenic ("off-on") and chromogenic (from colorless to blackish brown) sensing performance towards Hg ions. The fluorescence intensity was increased by 70 fold after the addition of Hg.