A facile construction of bifunctional core–shell–shell structured magnetic metal–organic frameworks for detection and removal of tetracycline

The sensitive detection and efficient removal of tetracycline (TC) residues are of great significance for improving food safety and preventing environmental pollution. Herein, a bifunctional core–shell–shell magnetic metal–organic framework was constructed (denoted as Fe3O4@[email protected]) by layer-by-layer self-assembly. The Fe3O4@[email protected] possessed the merit of superparamagnetism, unique porous structure, and large specific surface area, which could offer abundant multiaffinity sites for improving the capture ability of materials for TC (Qm = 144.9 mg/g). It was worth mentioning that the Fe3O4@[email protected] showed excellent optical properties, which could be employed as a fluorescence sensor for TC detection over a wide detection range (0.01–25 mg/L) and low detection limit (2 μg/L). Moreover, the practical feasibility of Fe3O4@[email protected] for TC sensing was also investigated in milk and honey. In this work, the synthesis method of a novel core–shell–shell structured magnetic MOF might have broader application prospects.