Synthesis and Analytical Application of a Novel Fluorescent Hg2+ Probe 3′, 6′-Bis(Diethylamino)-2-((2,4-Dimethoxybenzylidene)Amino)Spiro[Isoindoline-1,9′-Xanthene]-3-Thione

A novel probe, 3′,6′ - bis(diethylamino) -2- ((2,4-dimethoxybenzylidene)amino) spiro [isoindoline-1,9′-xanthene]-3-thione (RBS), was designed and synthesized. Its structure was characterized with elemental analysis, IR spectra and 1 H NMR. The probe displayed highly selective and sensitive recognition of Hg 2+ . Reacting with mercury ions in aqueous solution, its fluorescence intensity was enhanced significantly, while its color was changed from colorless to pink. So, a new fluorescence method of detection of Hg 2+ was proposed. Its dynamic response concentration range and detection limit for Hg 2+ were 5.00 × 10 −9  M to 1.00 × 10 −6  M detected and 1.83 × 10 −9  M, respectively. Satisfying results were obtained when the probe was applied to detect spiked Hg 2+ in samples.