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.