COF-1-modified magnetic nanoparticles for highly selective and efficient solid-phase microextraction of paclitaxel

Novel covalent organic framework-1 modified magnetic nanoparticles (M-COF-1) were prepared for extraction of paclitaxel from rat plasma samples. Paclitaxel is an important anti-cancer drug in clinical chemotherapy. COF-1 was immobilized on the surface of magnetic nanoparticles by bio-inspired polydopamine functionalization method because polydopamine can supply catechol groups for supporting the immobilization of COF-1. The formation of M-COF-1 has been confirmed by Fourier transform infrared spectroscopy and transmission electron microscopy . A M-COF-1-based extraction method was developed for selective extraction of paclitaxel in aqueous solutions. Extraction conditions were investigated, including sample pH value, acetonitrile content, extraction time and sample volume. By combining with HPLC, this method showed a good linear range of 0.1–200   ng/mL with a low limit of detection of 0.02   ng/mL. The method was also applied for the pretreatment of paclitaxel in rat plasma samples, which showed effective enrichment efficiency and good clean-up capacity. Recoveries were calculated to be 99.4–103.7% with relative standard deviations less than 2.3%.