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A Pyrene Derived CO2‑Responsive Polymeric Probe for the Turn-On Fluorescent Detection of Nerve Agent Mimics with Tunable Sensitivity
journal contribution
posted on 2017-08-18, 20:49 authored by Moumita Gupta, Hyung-il LeeA pyrene
based turn-on fluorescent polymeric probe was developed for the tunable
detection of nerve agent mimics. Glycidyl methacrylate (GMA) and dimethylacrylamide
(DMA) were copolymerized by reversible addition–fragmentation
chain transfer (RAFT) polymerization to yield poly-(glycidyl methacrylate-co-dimethylacrylamide) [p(GMA-co-DMA)](P1).
The subsequent reaction of the secondary amine of 2-(2-((pyren-1-ylmethyl)-amino)-ethoxy)-ethanol
with the epoxide unit of P1 yielded P2,
which can detect diethyl cyanophosphate (DCNP), a nerve agent mimic,
very efficiently by the turn-on fluorescence technique, induced by
DCNP promoted intramolecular N-alkylation in both the solution and
vapor phase. The lowest detection limit of P2 to DCNP
was obtained as 0.1 mM, which is close to the toxicity limit of Tabun.
Moreover, the detection of DCNP was successfully controlled by altering
the purging of CO2/N2 gases or tuning the pH
of the solution. P2 showed an efficient ON/OFF reversible
fluorescence response toward CO2 and N2 gases,
further helping tunable ON/OFF sensing of DCNP. The CO2-tunable detection of DCNP was further correlated to the pH-dependent
control of detection sensitivity. At low pH, no change in the fluorescence
enhancement was observed upon exposure to DCNP, whereas the fluorescence
intensity of the probe remarkably increased at high pH. Thus, these
CO2/pH controllable detection properties can offer new
insights into the design of new stimuli-responsive polymeric probes
with fluorescence turn-on detection of nerve agent mimics.