Development of coumarin derivatives as fluoride ion sensor

Fluoride ion is a vital trace element present in human body and a well-known very strong Lewis's base, its deficiency or overabundance creates severe hazards towards human health and environment. In this context, development of sensors for selective and sensitive detection of fluoride ion over other biologically competing anions is highly necessary. Coumarins, because of its unique properties like easy to derivatize, lower toxicity, high fluorescence quantum yield, large Stokes shift and excellent photo stability encouraged the researcher's worldwide for development of coumarin-based fluoride ion sensor. Herein, we described the development of coumarin based fluoride ion sensors since last two decades in an orderly manner. Most of the coumarin based receptors discussed here, selectively and sensitively detect fluoride ions based on the mechanism of fluoride ion induced hydrogen bonding/deprotonation/cleavage of any bulkier groups.