A near-infrared fluorescent probe for facile fluoride detection in environmental and biological systems

Abstract

Excessive fluoride (F⁻) exposure poses a threat to environmental and biological systems, necessitating rapid and reliable recognition. Here, a near-infrared (NIR) photoluminescent probe, CF–F, is fabricated from a coumarin-benzopyrylium backbone via a fluoride-triggered protection–deprotection protocol. Selective F⁻-induced Si–O scission releases emissive CF–OH, eliciting a turn-on NIR output at 660 nm. CF–F combines prompt response, superb selectivity, and a low detection threshold of 5.02 nM, succeeding in smartphone-assisted aqueous analyses as well as in vivo imaging in cells and zebrafish.