β-Cyclodextrin-MOF Nanoparticle Composites Anchored on Polystyrene for Reusable Adsorption of Sulfonamide Antibiotics

The practical application of metal–organic frameworks (MOFs) in water remediation is often hindered by their powdery nature, which causes aggregation, difficult recovery, and potential secondary pollution. To address this, we pioneer an integrated strategy of chemical bonding and in situ epitaxial growth to fabricate, for the first time, a robust and substrate-anchored cyclodextrin-based MOF (CD-MOF) composite. The innovation centers on using ethylenediamine-modified β-cyclodextrin (EDA-β-CD) as chemically grafted nucleation sites on aldehyde-functionalized polystyrene to guide the oriented growth of CD-MOF, yielding a well-adhered PS-CD-MOF composite. This novel material exhibits excellent adsorption of sulfonamide antibiotics (e.g., 5.55 μg·mg–1 for sulfadimethoxine) with rapid kinetics. More importantly, it demonstrates outstanding reusability over multiple cycles while maintaining structural integrity, thereby overcoming a key limitation of powder MOFs. Its versatile adsorption across different sulfonamides confirms the success of the synthesis strategy and highlights its potential as a stable, recyclable platform for waste liquid.