A new sensitive and selective chromogenic and fluorescent chemodosimeter for Hg(Ⅱ) in aqueous media and its application in live cell imaging

• A new rhodamine-based chemodosimeter(L2) was synthesized and characterized.
• L2 exhibited high selectivity and sensitivity detection of Hg2+ in aqueous solution.
• The significant changes in color could be used for naked-eye detection.
• The fluorescence imaging experiment demonstrated its value of practical application.

A new rhodamine-based chemodosimeter(L2) was synthesized and characterized, which contained a tosyl group acted as a strong electron acceptor. As expected, L2 exhibited high selectivity and excellent sensitivity in both absorbance and fluorescence detection of Hg2+ in aqueous solution. The coordination of L2 with Hg2+ was chemically nonreversible and it was based on the fact that Hg2+ exhibited a strong thiophilic affinity. Addition of Hg2+ to an ethanol aqueous solution of L2 resulted in a color change from color-less to obvious pink color, these significant changes in color could be used for naked-eye detection. Furthermore, fluorescence imaging experiments of Hg2+ ions in living MGC803 cells demonstrated its value of practical applications in biological systems.