Self-assembled magnetic nanoplatform Fe3O4@SiO2-NH2@Au for magnetic solid-phase extraction of bisphenol A

Developing magnetic adsorbent that combines the merits of quick response, excellent enrichment capacity, uniform and stable dispersivity is of paramount importance in pollutants pretreatment. In this work, tunable strawberry-like Fe3O4 @SiO2-NH2 @Au@ 2-ME magnetic solid phase extraction materials were prepared via assembly method. The obtained nanocomposites were characterized using scanning electron microscopy, X-ray diffraction spectroscopy, infrared spectroscopy, X-ray photoelectron spectroscopy, and whereafter the preparation method was optimized. Integrating magnetic solid-phase extraction with high-performance liquid chromatography and fluorescence detection, a comprehensive enrichment and detection method toward bisphenol A (BPA) was well established. This method demonstrated high efficiency and rapidity, achieving rapid enrichment of BPA. The as-developed method exhibited good linear correlation within the range of 10.0–500 μg·L−1, with a recovery of 85–92%. It showed excellent sensitivity and reproducibility in BPA extraction with low limit of detection (LOD, 0.274 μg·L−1), limit of quantitation (LOQ, 0.913 μg·L−1) and relative standard deviation (RSD, 1.5%, n = 6), respectively. The proposed Fe3O4 @SiO2-NH2 @Au nanoplatform firmly supports the envision that proper surface functionalization of magnetic substrate could promote the enrichment capacity toward various pollutants in actual application scenarios.