Reaction-based Hg2+ signaling by excimer–monomer switching of a bis-pyrene dithioacetal

A novel reaction-based probe for fluorescence signaling of Hg2+ ions was developed. Selective Hg2+-induced cleavage of a dithioacetal resulting in switching from pyrene excimer to monomer emission was used for the signaling. Changes in excimer and monomer emissions of pyrene were readily employed for ratiometric signaling of Hg2+ ions in aqueous acetonitrile. Selective signaling of Hg2+ ions over other common metal ions was observed with a detection limit of 9.8 × 10−7 M.