A Donor-π-Donor Type Ratiometric Chromogenic Molecular Optode for Efficient Recognition of Sarin Analog, Diethylchlorophosphate.

The extremely toxic G-series nerve agents are synthetic chemical compounds developed for making synthetic weapons for terrorist attacks and mass destruction in war. So, for these dangerous nerve agents, quick and precise detection is needed to rescue nature and public health. In this study, we have developed a colorimetric probe [(E)-N1-((E)-3-(4-(dimethylamine) phenyl) allylidene)-N4, N4-dimethylbenzene-1,4-diamine] (DPAD) with high selectivity and sensitivity for the on-spot identification of lethal sarin gas surrogate diethylchlorophosphate (DCP) in both the solid and liquid phase individuality. Upon contact with DCP, the probe exhibits a distinctly purple color, visible with bare eyes. After the addition of triethylamine (TEA) to our sensor, DPAD-DCP solution reversed the color back to pale yellow. To enable rapid detection and quantification of our colorimetric probe demonstrates exceptional selectivity for DCP within the nM range (3.2 nM). For an instant observation and quantification of DCP, we also experimented using paper strip-based kits. To further enhance detection, we also conducted a dip-vial conical flask and dip-stick experiment to recognize DCP in the vapor stage across the numerous inorganic phosphate (IPs), organic phosphate (OPs), and other deadly analytes. Additionally, for real-time and practical application, we employed a smartphone-based readout technique to facilitate on-the-spot detection for DCP.