A benzoxazole-based turn-on fluorosensor for rapid and sensitive detection of sarin surrogate, diethylchlorophosphate.

A benzoxazole-based fluorosensor (IMP) has been synthesized and employed for the selective and sensitive detection of sarin surrogate, diethylchlorophosphate (DCP) in solution, and gas phase, respectively. Remarkable turn-on fluorescence is observed due to the introduction of DCP in the solution of IMP because of inhibition of the intramolecular charge transfer process and disruption of the excited state intramolecular proton transfer (ESIPT) mechanism. The synthesized IMP-based fluorescence sensor exhibits excellent selectivity, high sensitivity, and a wide linear range of 15-60 μM with a detection limit of 44 nM. Low-intense to highly intensified visible violet color could be seen by the naked eye under a portable 365 nm UV lamp due to the addition of DCP in the solution of IMP. IMP-stained paper strips-based test kit experiment has been demonstrated to detect traces of DCP in stockpiles of related analytes. A dip-stick experiment for the detection of DCP vapor has also been demonstrated. The effectiveness of IMP in detecting DCP established that it might be used as a signal tool for real sample analysis.