Ultrasensitive Recognition of Trace Nerve Agents Enabled via a Thermally Activated Delayed Fluorescence-Based Fluorescent Probe

The development of fluorescent probes for the detection of nerve agents has been a significant focus of research due to their lethal toxicity to humans. Inspired by the excited state properties of thermally activated delayed fluorescence (TADF), we designed two visualized fluorescence probes, PT and PPT, that exhibit characteristics of delayed fluorescence and aggregation-induced emission. These probes are intended for the rapid and highly sensitive detection of diethyl chlorophosphate (DCP). Upon exposure to DCP vapors, the PT and PPT probes demonstrated rapid fluorescence quenching in less than 5 s, which was accompanied by a color change from yellow to red. The limits of detection for the probes were determined to be 3.0 and 2.9 ppb. Furthermore, we demonstrate that the reduction of acid interference through the use of dispersed SiO₂ is an important step in the fabrication of N-heterocyclic nerve agent probes. Importantly, we also constructed a portable fluorescence detector that incorporates these films as key components, validating its applicability through the successful detection of nerve agents.