A naphthimide-based ratiometric fluorescent probe for selective and visual detection of phosgene in solution and the gas phase

As a colorless, highly toxic and widely used chemical reagent, phosgene poses a potentially serious threat to public health and environmental safety. Therefore, there is an urgent need to develop a simple and sen-sitive method for detecting phosgene. In this work, a ratiometric fluorescent probe (NED) for phosgene was developed by utilizing 4-substituted 1,8-naphthimide unit as the fluorophore and ethylenediamine as the recognition moiety. The probe NED undergoes intramolecular cyclization reaction with phosgene, resulting in a remarkable ratiometric fluorescence response. The probe NED displays high sensitivity (LOD = 4.9 nM), excellent ratiometric fluorescence signal, and high selectivity toward phosgene over other relevant analytes. In addition, paper test strip capable of visually detecting gaseous phosgene has also been fabricated. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

A ratiometric fluorescent probe (NED) for detecting phosgene was developed, showing high sensitivity and selectivity, along with a paper test strip for visually detecting gaseous phosgene.