Ratiometric sensing of nerve agent mimic DCP through in situ benzisoxazole formation

In recent year syria rejuvenate interest in chemical warfare agents (CWAs) for terrorist attacks. Nerve agents are the most scandalous chemicals and can cause death of a person owing to the inhibition of acetyl cholinesterase activity. In this article, we report a colorometric and ratiometric fluorescent probe 4-diphenylamino-2-hydroxy benzaldehyde oxime (TPOD) that could be efficient of instant and real-time recording of DCP vapour. Upon reaction with DCP, bathochromic shift from similar to 463 to similar to 532 nm was observed due to the inhibition of PET from oxime-hydroxyl to the triphenyl amine moiety and cyclization to the benzisoxazole. The transformation from oxime to benzisoxazole was confirmed by NMR and HRMS data. The probe TPOD can be applied on a portable and cost effective test kits where in presence of DCP vapour dramatic color and fluorescence change were observed within 30 s. Furthermore, the probe can efficiently detect DCP in presence of other nerve agents and electrophile and the detection limit is 0.14 mu M. Moreover to evaluate the sensing mechanism we have prepared a control compound TPD whose crystal structure and non covalent interactions have been incorporated. To achieve the on-site application of TPOD we have performed an experiment in soil sample to detect trace amount of DCP. Moreover the probe can be useful in cellular imaging of DCP containing bio-samples. Thus the probe TPOD is an auspicious, instant and on site monitoring ratiometric fluorescent probe for selective DCP detection in presence of other interfering nerve agents.