In this paper, we specifically designed and synthesized an excellent colorimetric and ratiometric fluorescent sensor DPA-CI for rapid and convenient detection of the highly toxic phosgene. DPA-CI was developed by incorporated a diphenylamine (DPA) and a 2-imine-3-benzo[d]imidazole as the enhanced push–pull electronic structure into the coumarin fluorophore matrix. The sensor DPA-CI towards phosgene sensing exhibited both visible colorimetric and ratiometric fluorescent color change in solution and in gaseous conditions with TICT and AIE mechanism respectively, which can be easily distinguished by using the naked eye. Also, the sensor DPA-CI showed splendid sensing performance such as excellent selectivity, rapid response (less than 8 s in THF and 2 min in gaseous condition), and fair sensitivity (limit of detection less than 0.11 ppm in gaseous condition and 0.27 μM in solution). The design strategy based on enhanced push–pull electronic structure with AIE and TICT properties will be helpful to construct a solid optical sensor with excellent potential application prospects for portable and visual sensing of gaseous phosgene through distinct color and ratiometric fluorescence change by the naked eyes.

在本文中，我们专门设计并合成了一种出色的比色和比例荧光传感器DPA-CI，用于快速便捷地检测高毒性的光气。DPA-CI是通过将二苯胺（DPA）和2-亚胺-3-苯并[d]咪唑作为增强的推挽电子结构掺入香豆素荧光团基质而开发的。面向光气感测的传感器DPA-CI分别通过TICT和AIE机制在溶液和气态条件下均显示可见比色和比例荧光变化，这可以通过肉眼轻松辨别。另外，传感器DPA-CI表现出出色的传感性能，例如出色的选择性，快速响应（在THF中少于8 s，在气体条件下2分钟）和中等灵敏度（在气体条件下的检测限小于0.11 ppm和在溶液中的检测限小于0.17 ppm）。基于具有AIE和TICT特性的增强型推挽式电子结构的设计策略将有助于构建一种固体光学传感器，该传感器具有良好的潜在应用前景，通过裸眼的明显颜色和比例荧光变化，可以直观地检测气态光气。