Abstract:
The unregulated use of chemical weapons has
aroused researchers to develop sensors for chemical warfare
agents (CWA) and likewise to abolish their harmful effects, the
degradation through catalysis has great advantage. Chemically,
the CWAs are versatile; however, mostly they contain
organophosphates that act on inhibition of acetyl cholinesterase. In this work, we have designed and synthesized some
novel benzimidazolium based fluorescent cations and their
fluorescent aggregates were fabricated using anionic surfactants
(SDS and SDBS) in aqueous medium. The prepared
fluorescent aggregates have shown aggregation induced
emission enhancement, which was further used as detection
of chemical warfare agent in aqueous medium. The aggregates (Benz-2/SDBS and Benz-3/SDBS) have shown significant
changes in emission profile upon interaction with diethylchlorophosphate. Contrarily, the pure dipodal receptor Benz-4 has not
shown any response in emission after interaction with organophosphate, and consequently, it was concluded that
benzimidazolium cation plays a decisive role in sensing. The mechanism of sensing was fully validated using 31P NMR
spectroscopy as well as GC-MS, which highlights the transformation of diethylchlorophosphate into diethylhydrogen phosphate.
The aggregates selectively interact with diethylchlorophosphate over other biological important phosphates.
