Synthesis and application of a Tb-MOF for the selective fluorescent detection of tetracycline in foods

Tetracycline (TC) residues are frequently detected in food products and pose potential risks to human health, thus driving the demand for rapid and reliable analytical methods. In this study, a terbium-based metal-organic framework (Tb-MOF) constructed from a boronic-acid–containing ligand, 3,5-dicarboxyphenylboronic acid (5-bop), was synthesized via a one-pot hydrothermal route and evaluated as a fluorescent probe for TC. Comprehensive structural and optical characterization confirmed the successful synthesis of the crystalline Tb-MOF and its characteristic strong green emission under UV excitation. Mechanistic studies indicated that the fluorescence quenching of Tb-MOF by TC originates from dynamic quenching processes including the inner filter effect (IFE) and photoinduced electron transfer (PET). The Tb-MOF probe exhibited a linear response to TC in the concentration range of 0 to 60 μmol/L, with a detection limit of 153 nmol/L. Furthermore, the Tb-MOF sensor was successfully applied to detect TC in real-world food samples including milk and beef, yielding satisfactory recovery and accuracy. This work provides an effective alternative strategy for the quantitative monitoring of TC in complex food substrates, highlighting its significant potential for enhancing food safety assurance.