10.1039/b811247a
The research focuses on the development of a new chromogenic protocol for the selective detection of nerve agent mimics, which are chemical compounds that simulate the behavior of actual nerve agents such as Tabun, Sarin, and Soman. The study addresses the need for quick and reliable detection methods due to the high toxicity and ease of production of these chemicals. The researchers synthesized a chromogenic probe, referred to as chromoreactand 1, using 2-(2-(dimethylamino)phenyl)ethanol (DAPE) as a building block. This probe was designed to undergo a colorimetric change upon interaction with certain organophosphorus (OP) substrates, which are nerve agent simulants. The probe's reactivity was tested with diethyl chlorophosphate (DCP), diisopropyl fluorophosphate (DFP), and diethyl cyanophosphate (DCNP) in acetonitrile. The reaction resulted in a hypsochromic shift, indicating a color change from yellow to colorless due to an intramolecular cyclization process. The detection limit for DCNP and DCP was found to be 1.0 x 10^-4 mol dm^-3. Further experiments involved the preparation of compound 2 to confirm the reaction mechanism through NMR spectroscopy. The probe's reactivity was also studied in mixed water–acetonitrile solutions at pH 7, showing selective bleaching in the presence of DCP, DFP, and DCNP. Kinetic studies were performed to determine the rate constants and half-life of the reaction. The potential application of the probe for in situ sensing was demonstrated by adsorbing it onto silica gel and testing its response to DCP vapor and solution. The study concludes that the developed chromoreactand is a promising alternative for the colorimetric detection of nerve agent simulants, showing selectivity and a rapid response.
