Highly selective fluorescence enhancement chemosensor for Hg2+ based on rhodamine and its application in living cells and aqueous media

A rhodamine-based chemosensor (RP) was synthesized and characterized as a highly selective and sensitive probe for Hg2+ in aqueous media. A prominent fluorescence enhancement at 576 nm was observed in the presence of Hg2+, accompanied by the change in the absorption spectrum. With the optimum condition described, the response was linearly proportional to the concentration of Hg2+ in the range 0–1 μM with a detection limit of 0.012 μM. Confocal laser scanning microscopy experiments showed that RP can sense the Hg2+ in living cells with a fluorescence enhancement signal. The proposed method was also successfully applied to the determination of Hg2+ in tap water, river water samples.