A selective fluorescent probe for an organophosphorous nerve agent mimic via an oxime-to-isoxazole cascade reaction

A class of chemical warfare agents and their facile use in terrorist attacks underscores the need to develop accurate system to detect these chemicals. For this paper, we synthesized and developed a new highly selective and sensitive fluorescence probe based on fluoresceinyloxime for the detection of a nerve agent mimic. The synthesized probe underwent an abnormal cascade reaction from oxime to isoxazole in DMF/HEPES buffer (1/1, v/v, pH 7.0). The probe responded by quenching the fluorescence intensity in very short time (within seconds) and gave a naked eye detection by changing the colour of the solution from dark orange to very light green with a detection limit of 0.18 µM. The probe not only shows sensitivity and selectivity in the liquid phase, but can also be applied for the detection of nerve agents in the vapour phase with a clear colour change easily observed by the naked eye.