Preparation of a novel fluorescent material ZIF-8@ZIF-8 and its application strategy in the detection and stripping of the tetracyclines residue in food.

The substantial presence of tetracyclines (TCs) and their resistant degradation properties have rendered them prevalent residues in animal-sourced foods. This paper introduced a novel metal-organic framework (AuNCs@ZIF-8@CDs@ZIF-8) that encapsulated carbon dots (CDs) and gold nanoclusters (AuNCs). This framework synergistically combined fluorescence emission with the porous characteristics of multi-shell metal-organic frameworks, facilitating the development of sensors and adsorbents specifically designed for tetracycline antibiotics. The fluorescence intensity ratio (F0/F) showed a good linear relationship with the concentration of TCs in the range of 0-100 μmolL-1, with a detection limit of 0.0903 μmolL-1. Additionally, AuNCs@ZIF-8@CDs@ZIF-8@SA/CMC hydrogel sensors were constructed and visualized for TC detection using a smartphone. The hydrogel demonstrated a TC loading capacity as high as 551.137 mg/g. The research provided a new strategy for developing the integrated technology of quantitative detection, rapid visualization detection, and adsorption removal of pollutant residues in food.