Double imprinted films based on mesoporous-HKUST-1 for superior bisphenol A removal: performance evaluation and...

Metal-organic frameworks (MOFs) with high surface area and tunable pore structures have been widely used as molecularly imprinted polymer (MIP) supports. However, conventional microporous MOF structures restrict imprinting layer formation on their internal surfaces, thus limiting accessible imprinting sites. In this study, mesoporous HKUST-1 (Me-HKUST-1) was prepared using sodium dodecyl sulfate (SDS) as a soft template, employed as a support to construct a double-imprinted polymer composite (Me-HKUST-1@MIP). Introduction of mesopores increased support accessibility and promoted formation of additional imprinting sites, enabling rapid and highly selective bisphenol A (BPA) adsorption. The results showed that the most probable Me-HKUST-1 pore size reached 24.34 nm, and Me-HKUST-1@MIP exhibited an adsorption capacity of 187.83 mg g^-1 toward BPA within 60 min, 1.45-fold that of traditional microporous HKUST-1@MIP (129.28 mg g^-1). The adsorption behavior was well fitted by the Elovich kinetic model and Freundlich isotherm, indicating heterogeneous adsorption. Me-HKUST-1@MIP exhibited superior selectivity, with a 2.22-fold higher recognition ability than HKUST-1@MIP in a mixed system containing BPA, bisphenol B (BPB), 2,4-dinitrophenol (2,4-NP), chloramphenicol (CAP), and sulfadiazine (SD). Mechanistic analysis combined with two-dimensional correlation infrared spectroscopy (2D-COS IR) suggested the sequential evolution of cavity-related responses, hydrogen bond-associated interactions, and subsequent guest accumulation during adsorption. In actual matrix-spiked samples, Me-HKUST-1@MIP achieved 81.63-109.74% recovery for BPA with relative standard deviations (RSDs) < 6.74% and could be reused for 15 cycles. These results indicate that increasing porous crystalline support pore size is an effective strategy for improving MIP adsorption performance and practical applicability toward organic pollutants.