A restricted access molecularly imprinted polymer coating on metal–organic frameworks for solid-phase extraction of ofloxacin and enrofloxacin from bovine serum†
A restricted access molecularly imprinted polymer (RAMIP) crosslinked with bovine serum albumin (BSA) was prepared on the surface of the mesoporous UiO-66-NH2 metal–organic framework (MOF). The surface morphology, imprinting behavior, and protein exclusion properties of UiO-66-NH2@RAMIP@BSA were investigated. The maximum adsorption capacity was 50.55 mg g−1 for ofloxacin, with a 99.4% protein exclusion rate. Adsorption equilibrium was reached in 9 min. Combined with RP-HPLC, a solid-phase extraction column filled with UiO-66-NH2@RAMIP@BSA was used to selectively enrich and analyze ofloxacin and enrofloxacin antibiotics from bovine serum with recoveries of 93.7–104.2% with relative standard deviations of 2.0–4.5% (n = 3). The linear range and the limit of detection were 0.1–100 μg mL−1 and 15.6 ng mL−1, respectively. These results suggest that UiO-66-NH2@RAMIP@BSA is an efficient pretreatment adsorbent for biological sample analysis.