Rapid and ratiometric fluorescent detection of phosgene by a red-emissive ESIPT-based-benzoquinolone probe.

[Display omitted] • A novel red-emissive ESIPT-based quinolone probe enables ratiometric detection of phosgene. • This probe exhibits the rapid response (in 10 s), stable signal output (last for 10 min), high sensitivity (LOD ∼ 6.7 nM), and distinct emission color change (red to green) towards phosgene. • The sensing mechanism have been investigated by using 1H NMR, HRMS and fluorescence lifetime techniques, confirming that amidation reaction effectively suppressed the ESIPT process. • The probe-embedded nanofibers were facilely prepared by electrospinning and successfully employed to monitor gaseous phosgene with high specificity. Phosgene is a highly toxic gas that poses a serious threat to human health and public safety. Therefore, it is of great importance to develop an available detection method enabling on-the-spot measurement of phosgene. In this paper, we report a novel ESIPT fluorescent probe for phosgene detection based on quinolone fluorophore. This probe exhibits rapid response (in 10 s), stable signal output (last for 10 min), high sensitivity (LOD ∼ 6.7 nM), and distinct emission color change (red to green) towards phosgene. The sensing mechanism was investigated by using 1H NMR, HRMS and fluorescence lifetime techniques, confirming that the amidation reaction between phosgene and quinolone effectively suppressed the ESIPT process of probe. Eventually, this probe was fabricated into polymer nanofibers by electrospinning and successfully employed to monitor gaseous phosgene with high specificity. This work provided a promising analytical tool for rapid and ratiometric detection of phosgene both in solution and in the gas phase. [ABSTRACT FROM AUTHOR]