Heterocyclic aromatic nitrogen carbon dots as sprayable fluorescent probes for the identification of real chemical warfare agents

초록

Chemical warfare agents (CWAs) utilized in wartime or terrorist incidents pose a lethal threat due to their extreme toxicity and potential for wide-area contamination. To ensure the survival of military personnel and civilians, as well as to facilitate rapid responses in such hazardous situations, the development of cost-effective sprayable sensor probe for identifying contaminated areas is required. In this study, we synthesized heterocyclic aromatic nitrogen carbon dots (N-CDs) via a solvothermal reaction to serve as fluorescent probe for on-site CWAs identification. The resulting N-CDs exhibit a high photoluminescence quantum yield (PLQY) of 0.83. The N-CDs sensor was confirmed to exhibit high sensitivity for undiluted CWAs simulants and high selectivity against various organophosphorus molecules. Through cross-validated analysis, the sensing mechanism was identified as a nucleophilic substitution reaction. Specifically, the nitrogen atoms on the N-CDs, including pyrrolic and pyridinic nitrogens, nucleophilically attack the electrophilic phosphorus center of diethyl chlorophosphate (DCP), displacing the chloro group to form covalent N-P bonds. This binding at multiple nitrogen configurations alters the electronic structure of the N-CDs, resulting in fluorescence quenching and a red-shifted absorption response, resulting in distinct colorimetric changes. Furthermore, the on-site identification of real CWAs, namely Soman (GD), Sarin (GB), Cyclosarin (GF) and Mustard gas (HD) was successfully demonstrated on various substrates via a spray test, providing their potential for rapid and practical hazard assessment in realistic operational environments. © 2026 Elsevier B.V.

키워드