Cooperation between Eu MOF and glycerol for luminescent sensing of nerve agent mimic vapor

There is a global interest in developing rapid and reliable sensing methods for vapors of extremely toxic nerve agent weapons due to public safety and national security concerns. Luminescence detection is regarded as an attractive way to meet the demand for fast reporting as well as disturbance avoidance. In this study, the potentials of Ln-based luminescent metal-organic framework (MOF) for nerve agent sensing is demonstrated and the cooperation with glycerol is developed as a facile method for sensitivity and selectivity enhancement. Specifically, a layer structural pyrazole-functionalized Eu MOF based sensing film, exhibits 1.6-fold enhancement of ligand fluorescence and 50% quenching of Eu emission in the presence of glycerol after 20 ​s of exposure to saturated vapor of nerve agent simulant. The film not only achieves a detection limit as low as 0.7 ​ppm but shows selectivity versus common interferences like NH₃. Mechanism study indicates that phosphorylation of –OH from glycerol occurs accompanied with the protonation of pyrazole group, much similar to the initial inhibition of acetylcholinesterase by nerve agents.