Three-fold interpenetrated metal–organic framework as a multifunctional fluorescent probe for detecting 2,4,6-trinitrophenol, levofloxacin, and l-cystine

Abstract

Multifunctional metal–organic frameworks (MOFs) as fluorescent probes have been proven to be practical tools for future sensing devices. We herein report a new luminescent MOF, {[Zn₃(TLA)₂(H₂O)₂(4-abpt)₂]·5CH₃OH}_n (1) (trimellitic acid = H₃TLA, 4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole = 4-abpt), which was synthesized under solvothermal conditions and then characterized. 1 has a three-dimensional polymeric coordination structure with a V-shaped trinuclear metal–oxygen [Zn₃] unit. The adjacent [Zn₃] units are further connected by TLA³⁻ and 4-abpt linkers, resulting in the generation of a 3D coordination polymeric network with obvious 3D channels. Moreover, 1 demonstrates a unique three-fold interpenetrated network and exhibits excellent chemical and thermal stabilities. Interestingly, 1 can be used as a sensitive and recyclable fluorescent probe for the detection of 2,4,6-trinitrophenol (TNP), levofloxacin (LVX), and L-cystine (L-Cys) with low limits of detection (LOD) of 5.24, 7.47 and 5.05 μM, respectively.