Reactivity-based amino-1,8-naphthalimide fluorescent chemosensors for the detection and monitoring of phosgene

Phosgene (carbonyl dichloride, COCl₂) is an extremely toxic and hazardous chemical warfare agent (CWA; schedule 3 substance) that poses significant threats to public safety and human well-being. Simultaneously, it is a commonly employed reagent in chemical synthesis in laboratories and industrial settings. Therefore, monitoring phosgene concentration levels is essential for handling them within the workplace and for safeguarding public security. Activity-based fluorescent probes are the most effective real-time detection methods currently used for the detection of CWAs. Reaction-based sensing offers excellent temporal and spatial resolution, minimal side effects, and quick response times. Recently, a plethora of reaction-based fluorescent probes have been designed for the detection of phosgene. This review provides an overview of the latest developments using amino-1,8-naphthalimide-based small-molecule fluorescent probes designed for phosgene detection/sensing. Additionally, we investigate the existing challenges and prospects in the field of reaction-based fluorescent probes for phosgene detection. Herein, various fluorescence sensors are categorized based on their reactions with phosgene, and each section highlights the reaction sites, sensing mechanisms, structure–function relationships, photophysical performances, and practical applications of these sensors. It is our aspiration that this review will provide valuable insights into the advancement of cutting-edge fluorescent probes tailored for phosgene detection and sensing.