A two fluorophore embedded probe for collective and ratiometric detection of Hg2+ and F− ions

•We have developed a fluorescein-rhodamine dyad 1 to detect Hg2+ and F‒ ions.•Dyad 1 ratiometrically detects Hg2+ and F‒ ions even at ppb levels.•The coexistence of other ions do not affect the Hg2+ and F‒ detection ability of 1.•Dyad 1 is stable at physiological pH and non-toxic to NIH 3T3 cells.•Moreover, dyad 1 permits the imaging Hg2+ or F‒ contaminated W138 cells.

A novel fluorescein-rhodamine dyad probe has been synthesized and its chemosensory applications are explored. Anion and cation specific responses of the probe permit ratiometric detection of Hg2+ and fluoride ions, individually and collectively, with different fluorescence outputs. The presence of other commonly coexistent ions does not affect the Hg2+ and fluoride ion detection ability of the probe. The probe is highly sensitive to Hg2+ and fluoride ions and it can detect Hg2+ and fluoride ions even at ppb level concentrations. The probe is non-toxic under the experimental conditions, cell permeable and useful for the imaging of intracellular Hg2+ and fluoride ions.

Graphical abstractA fluorescein-rhodamine dyad suitable for individual and collective detection of Hg2+ and F− ions in aqueous samples is synthesized and its application in live cell imaging is demonstrated. Figure optionsDownload full-size imageDownload as PowerPoint slide