A highly selective ratiometric visual and red-emitting fluorescent dual-channel probe for imaging fluoride anions in living cells

• A visual and red-emitting fluorescent dual-channel probe for F− was synthesized.
• The probe can detect F− by ratiometric absorption spectra with a 158 nm red-shift.
• The probe can detect F− in an aqueous solution by the fluorescence enhancement.
• The probe can monitor the changes of F− level in living cells.

Recently, growing attention has been paid to the accurate determination of fluoride anion (F−) in the environment and living systems for its toxicity and biological function investigation. In this paper, we developed a ratiometric visual and red-emitting fluorescent dual-channel probe (1) employed Si–O bond as a highly selective recognition receptor for imaging F− in living cells. Probe 1 possesses a potential internal charge transfer (ICT) structure, and displays a large (158 nm) red-shifted absorption spectrum and the color changes from yellow to blue upon addition of F− in the aqueous solution. In addition, probe 1 can be used to detect F− quantitatively by the ratiometric absorption and turn-on fluorescence spectroscopy methods with excellent sensitivity. Finally, the results of its application to bioimaging of F− in living cells show that probe 1 would be of great benefit to biomedical researchers for investigating the effects of fluoride in biological systems.