Supramolecular β-cyclodextrin porous framework for selective extraction of diclofenac from environmental waters

Diclofenac (DF), a widely used non-steroidal anti-inflammatory drug, is frequently detected in environmental waters at ng/L to μg/L levels, requiring sensitive, selective, and affordable analytical methods for routine monitoring. Here, we developed and validated a supramolecular β-cyclodextrin-based porous organic polymer (POP) as a high-performance solid-phase extraction (SPE) sorbent for DF preconcentration from aqueous samples prior to UV–Vis analysis. The POP, synthesized from (2-hydroxypropyl)-β-cyclodextrin acrylate, was characterized by FTIR, FT-Raman, XRD, TGA, N 2 sorption, SEM, and ζ -potential measurements, confirming its porous, thermally stable structure, β-cyclodextrin-rich network, and inclusion complex formation. SPE parameters affecting extraction efficiency (EE) and enrichment factor (EF), including eluent type and volume, flow rates, sorbent mass, and conditioning pH, were optimized using one-factor-at-a-time studies and Box-Behnken design. The method exhibited linearity over 0.1–10 mg/L (method limit of detection: 18.0 ± 0.4 μg/L; method limit of quantification: 59.9 ± 1.2 μg/L). Field emulation experiments at 1500 ng/L DF in 1 L samples demonstrated EF values of 647 ± 159 (ultrapure water) and 549 ± 26.4 (real seawater), with recoveries of 64.7 ± 15.9% and 54.9 ± 2.6%, respectively. Compared to conventional C18 cartridges, the POP provided enhanced EE (98.75 ± 1.75%) and EF (373 ± 15 a.u.), highlighting its remarkable preconcentration capability. Molecular dynamics simulations revealed multi-point electrostatic and halogen-bonding interactions driving DF selectivity, while FT-Raman analysis of the POP-DF after sample loading confirmed the formation of an inclusion complex between the solid sorbent and the analyte. The results demonstrate the potential of β-cyclodextrin-functionalized POPs as efficient sorbents for preconcentration in trace-level pharmaceutical analysis of complex aqueous matrices. • Novel β-cyclodextrin porous organic polymer synthesized for selective diclofenac preconcentration from environmental waters. • Superior extraction efficiency (98.75%) and enrichment factor (373) compared to conventional C18 adsorbents. • Systematic optimization via Box-Behnken design achieving limit of detection of 18.0 μg/L with linear range 0.1–10 mg/L. • Molecular simulations reveal electrostatic and halogen bonding-driven selective recognition mechanisms.