Hollow-structured Fe3O4@SiO2 nanoparticles: Novel synthesis and enhanced adsorbents for purification of plasmid DNA

Abstract

Fe3O4 @SiO2 core-shell-structured nanoparticles are expected to act as nanoabsorbents or nanocarriers because of the magnetic properties of the internal Fe3O4 and the inherent properties of the external SiO2. Plasmid DNA, a small class of nucleic acid, is isolated and purified by the SiO2 surface of magnetic beads. Improvement of the specific surface area of the SiO2 coating layer under specified conditions greatly contributes to the purification performance of the material. As a means to achieve this, one way to maximize the surface area is to create a hollow structure by adding a coating layer. However, the process and environmental burdens associated with fabricating a hollow structure are some of the obstacles that currently prevent utilization of this method. This study proposes a novel synthesis method based on the use of water-soluble surfactant, which can form an interlayer while simultaneously acting as a bridge between a core and a shell. The morphology changes of the SiO2 layer depending on the crosslinking agent content were investigated, and the optimal conditions for hollow-structure generation were established. The improved surface properties dramatically improved the purification efficiency of plasmid DNA.