Dual-ligand europium-based metal–organic frameworks and hydrogels for sensitive ratiometric fluorescent detection of tetracyclines in food

, respectively. In actual sample detection, the spiked recoveries for milk and pork are 91.0-106.8% and 89.7-106.4%, respectively, with a relative standard deviation (RSD) ≤ 6.5%. Furthermore, as the concentration of TCs increases, the intensity of the purple fluorescence emitted by the hydrogel shows a gradual downward trend, showing a good linear relationship. The method possesses high selectivity, anti-interference capability, and rapid response characteristics, providing reliable technical support for on-site monitoring of TC residues in animal-derived foods.