Chromo-Fluorogenic Detection of Soman and Its Simulant by Thiourea-Based Rhodamine Probe
Shengsong Li,
Yongchao Zheng,
Weiqiang Chen,
Meiling Zheng,
He Zheng,
Zhe Zhang,
Yan Cui,
Jinyi Zhong,
Chonglin Zhao
Affiliations
Shengsong Li
Research Institute of Chemical Defense, Beijing 102205, China
Yongchao Zheng
Research Institute of Chemical Defense, Beijing 102205, China
Weiqiang Chen
Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
Meiling Zheng
Laboratory of Organic NanoPhotonics and CAS Key Laboratory of Bio-Inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
He Zheng
Research Institute of Chemical Defense, Beijing 102205, China
Zhe Zhang
Research Institute of Chemical Defense, Beijing 102205, China
Yan Cui
Research Institute of Chemical Defense, Beijing 102205, China
Jinyi Zhong
Research Institute of Chemical Defense, Beijing 102205, China
Chonglin Zhao
Research Institute of Chemical Defense, Beijing 102205, China
Here, we introduced a novel thiourea-based rhodamine compound as a chromo-fluorogenic indicator of nerve agent Soman and its simulant diethyl chlorophosphate (DCP). The synthesized probe N-(rhodamine B)-lactam-2-(4-cyanophenyl) thiourea (RB-CT), which has a rhodamine core linked by a cyanophenyl thiosemicarbazide group, enabled a rapidly and highly sensitive response to DCP with clear fluorescence and color changes. The detection limit was as low as 2 × 10−6 M. The sensing mechanism showed that opening of the spirolactam ring following the phosphorylation of thiosemicarbazides group formed a seven-membered heterocycle adduct, according to MS analysis and TD-DFT calculations. RB-CT exhibited high detecting selectivity for DCP, among other organophosphorus compounds. Moreover, two test kits were employed and successfully used to detect real nerve agent Soman in liquid and gas phase.