Magnetic separation of nucleic acids from various biological samples using silica-coated iron oxide nanobeads

Magnetic nanobeads can be applied to the magnetic separation of nucleic acids which can be used for diagnosing infectious and genetic diseases of patients. In this study, core-shell structured silica-coated iron oxide (Fe₃O₄@SiO₂) nanobeads with a core size distribution of 40–50 nm and a shell thickness of ∼ 10 nm were synthesized and applied to the magnetic separation of nucleic acids from various biological samples such as cancer cells, viruses, and bacteria. The iron oxide core provided strong superparamagnetic properties with a high saturation magnetization suitable for magnetic separation, and the silica shell provided binding surfaces for nucleic acids. The Fe₃O₄@SiO₂ nanobeads showed the successful magnetic separation performance for all samples. [Figure not available: see fulltext.]