Nowadays, the practical applications of metal-organic framework (MOF)-based fluorescence detectors are severely hindered because of the complex synthesis process of linkers or heavy metal contamination. The development of a simple, inexpensive, and environmentally friendly fluorescence sensing system remains a huge challenge. In this study, we designed and synthesized a TPE@γ-CD-MOF-K complex using the facile in situ encapsulation method. The unique pore structure of γ-CD-MOF allowed it to effectively include TPE and explosives as guests simultaneously. The TPE@γ-CD-MOF-K showed stronger fluorescence emission than TPE and sensitive fluorescence quenching activities in response to nitro-aromatic compounds in the liquid phase with detection limits as low as 3 ppm. Furthermore, TPE@γ-CD-MOF-K can also effectively detect nitro-aromatic compounds in the solid state, which is very convenient for practical detection of explosives. The unique pore structure of γ-CD-MOF-K and the interaction between K+ and nitro compounds play important roles in solid-state quenching.
Keywords: detecting in liquid and solid phase; fluorescence sensing; sensing mechanism; tetraphenylethylene; γ-CD-MOF-K.