A new 3-hydroxyphthalimide-based turn-on fluorescent probe for Hg2+ detection in aqueous solution

A new 3-hydroxyphthalimide-based turn-on fluorescent probe is designed and synthesized. This probe can be used to determine the presence of Hg2+ ions by fluorescence spectroscope with high selectivity over other metal ions in aqueous solution. The analytical detection limit for Hg2+ is as low as 6.5 × 10−7 M. The recognition mechanism is attributed to Hg2+-promoted carbonothioate group cleavage and a subsequent excited-state intramolecular proton transfer mechanisms.