Knitting Organic Cage into Hyper Cross-Linked Polymers for the Efficient Capture of Fluoroquinolones in Pork Samples

Considering the ubiquitous presence and hazardous effects of fluoroquinolone antibiotics (FQs), developing efficient methods for their detection has become imperative to safeguard human health. In this work, we synthesized a porous organic cage-based novel hyper-cross-linked polymer bearing multiple amino moieties (denoted as Cage-HCP-NH2) through knitting and reduction of nitro-functionalized organic cage. The Cage-HCP-NH2 exhibits high porosity (0.258 cm3 g–1) and big specific surface area (255 m2 g–1). Benefiting from unique cage architecture and synergistic interactions of hydrogen bonding, π–π stacking, and F−π and F–O interactions, Cage-HCP-NH2 demonstrated remarkable FQs adsorption capacity (730 mg g–1). Employing Cage-HCP-NH2 as a solid-phase extraction adsorbent coupled with ultrahigh performance liquid chromatography–tandem mass spectrometry, we developed a sensitive method for simultaneous detection of five FQs in pork matrices. Under the optimized conditions, the method achieves ultralow detection limits (0.015–0.060 ng g–1), high precision (relative standard deviation <9%), and good accuracy (method recoveries between 85% and 110%). The integration of cage architectures with functional groups opens new avenues for designing advanced functional materials targeting emerging contaminants.