Green β-cyclodextrin-based molecularly imprinted polymer for selective adsorption of sulfamethoxazole

Sulfamethoxazole (SMX), a widely detected antibiotic residue, threatens human health and ecosystems. For selective SMX removal, a green molecularly imprinted polymer (CD-MIP) was synthesized using β-cyclodextrin (β-CD) as functional monomer via a facile route, with comparative evaluation against conventional methacrylic acid-based MIP (MAA-MIP). Molecular conformation modeling and spectroscopic analysis revealed stronger SMX-β-CD binding, guiding polymer design. CD-MIP achieved both higher sorption capacity (8.02 mg/g) and imprinting factor (2.34) within 60 min compared to MAA-MIP (7.21 mg/g; 1.10). CD-MIP demonstrated eco-friendliness with minimal desorption, strong matrix interference resistance, and high SMX selectivity. Practical tests confirmed its high selectivity, underscoring its potential for safeguarding water supply security. Adsorption was driven by physisorption via hydrogen bonding, π-π and hydrophobic interactions, with imprinted sites playing a crucial role. The host-guest recognition capability of β-CD was preserved in CD-MIP, with diverse functional groups enabling efficient imprinting, and non-imprinted polymer controls could reduce template use. A comprehensive sustainability assessment incorporating green metrics, life cycle analysis and economic evaluation confirmed the environmental and economic viability. This work establishes β-CD-based molecular imprinting as a sustainable strategy that effectively combines inherent molecular recognition with environmental adaptability, offering a cost-effective solution for safeguarding water supply.