Construction of a stable Zn(II)-MOF based on mixed ligand strategy for fluorescence detection of antibiotics and Fe3+ ions

A stable Zn(II)-MOF ([Zn(L1)0.5(L2)0.5(H2O)]·DMF HBU-19, L1 = 2,3,5,6-tetra(4-carboxyphenyl)pyrazine, L2 = 1,2-di(4-pyridyl)ethylene) was synthesized by solvothermal method based on mixed ligand strategy. Crystal structure analysis showed that HBU-19 was a three-dimensional structure. PXRD and TG characterization indicated that HBU-19 possessed high phase purity and good thermal stability. HBU-19 can selectively detect two different antibiotics (nitrofurazone, NFZ and nitrofurantoin, NFT) simultaneously in aqueous media by fluorescence quenching. The detection limits are 19.6 μM and 17.9 μM, and the corresponding quenching coefficients are 5.2 × 104 M−1 and 5.5 × 104 M−1. In addition, HBU-19 exhibits a detection limit of 3.4 μM and a quenching coefficient of 2.24 × 105 M−1 for Fe3+ ions. The anti-interference experiments revealed that the compound showed good recognition selectivity. The possible sensing mechanisms have been also discussed in detail. Therefore, HBU-19 may be a promising sensor for detecting NFZ, NFT, and Fe3+ ions of wastewater.