A new method was developed for preparing monodisperse Fe₃O₄@SiO₂ magnetic core-shell nanoparticles via three steps. The obtained nanoparticles exhibit high saturation magnetization, good surface topography and dispersion as characterized by FTIR, SEM and VSM. The experimental results of hydrochloric acid treatment show that the obtained nanoparticles have excellent acid resistance and stable and compact silicon coating. The magnetic core-shell nanoparticles were further tested for purification of plasmid DNA from E. coli DH5a cells. The result of purification leaded to better adsorption, elution and purity results in comparison with isolated commercial extraction kit.

开发了一种通过三个步骤制备单分散Fe ₃ O ₄ @SiO ₂磁性核壳纳米粒子的新方法。通过FTIR，SEM和VSM表征，所获得的纳米颗粒表现出高饱和磁化强度，良好的表面形貌和分散性。盐酸处理的实验结果表明，所得纳米粒子具有优异的耐酸性和稳定而致密的硅涂层。进一步测试了磁性核-壳纳米颗粒从大肠杆菌DH5a细胞中纯化质粒DNA的能力。与分离的商业提取试剂盒相比，纯化的结果导致更好的吸附，洗脱和纯度结果。