In Vivo Fluoride Ion Detection and Imaging in Mice Using a Designed Near-Infrared Ratiometric Fluorescent Probe Based on IR-780

A ratiometric near-infrared fluorescence probe based on IR-780 is developed and applied to fluoride anion (F^-) detection in potable water and white flour as well as fluorescence imaging in living cells and mice. The proposed probe not only displays a linear ratiometric (F₇₄₀/F₆₉₀ nm) fluorescence response but also possesses near-infrared wavelengths to F^- with a detection limit of 0.2 μM. Moreover, the designed probe displays high selectivity toward F^-, which makes it feasible for F^- detection in potable water and white flour. More importantly, applied to monitor F^- in living HepG2 cells and male BALB/c mice, the probe indicates good biocompatibility and low cytotoxicity. However, no study for F^- detection has been reported by a ratiometric NIR fluorescent probe so far. We expect that this probe with superior properties has great potential for use in F^- detection in biological systems and in vivo studies.