Ultrafast-response, highly-sensitive and recyclable colorimetric/fluorometric dual-channel chemical warfare agent probes

In this paper, two donor (D)-acceptor (A) type of small organic fluorescent molecules (T1 and T2) based on terpyridine group are synthesized, characterized and used as colorimetric/fluorometric dual-channel probes towards diethylchlorophosphate (DCP, the mimic of chemical warfare agent sarin) not only in solution but also in gas phase featuring instantaneous responses, excellent recyclability, high selectivity and sensitivity. Interestingly though the discriminated units of both chemosensors are terpyridine, their fluorescent responded signals are different, which is due to the different electron-donating substituents of T1 and T2 caused the different responded mechanism to DCP. And the possible sensing mechanism was proved by using nuclear magnetic resonance (1H NMR, 31P NMR) spectra and natural transition orbitals calculations. Furthermore, facile testing filter paper-constructed strips with the visualization of colorimetric/fluorometric dual-channel responses based on T1 and T2 have been fabricated for real-time, on-site high selective and sensitive, recyclable monitor of DCP vapor.

Automated summary

In this study, two donor-acceptor type small organic fluorescent molecules (T1 and T2) based on the terpyridine group were synthesized and characterized for colorimetric/fluorometric dual-channel probe towards diethylchlorophosphate (DCP). The sensors showed high selectivity, sensitivity, and recyclability in both solution and gas phase, with different response mechanisms attributed to the electron-donating substituents on T1 and T2. The sensing mechanism was further supported by NMR spectra and calculations. Additionally, filter paper strips constructed with T1 and T2 were developed for real-time, on-site monitoring of DCP vapor with high selectivity and sensitivity.