Investigation of the Colorimetric Characteristics of VX in Squaraine-Based Solutions

Colorimetry is an important on-site detection method for organophosphorus compounds. O-Ethyl S-(2-diisopropylaminoethyl) methylphosphonothioate (VX) recognized as one of the deadliest chemical agents, and rapid VX great significance to public safety. In this paper, a squaraine derivative was synthesized probe molecules, sensing characteristics in colorimetric solution system containing tetrabutylammonium fluoride (TABF) were studied with UV−Vis spectroscopy, nuclear magnetic resonance (1H NMR), mass spectrometry. The results showed that binding thiol moiety quaternary ring changed molecular conjugation system, micro-trace achieved based on color change before after interaction squaraine, enabling limit be low 0.4 μg/mL. Moreover, colorimetry also possessed satisfactory sensitivity could detect from other pesticides (e.g., parathion dichlorvos), phosphorus-containing reagents diethyl chlorophosphate dimethyl methylphosphonate), benzene series toluene), acid base agents acetic triethylamine, respectively), which demonstrated squaraine-based provide fast, measurement detection. strategy research extended common approach nerve or pesticides.