Development of Fe3O4@SiO2 Magnetic Nanobeads Decorated with Graphene Oxide for Improved DNA Separation

In molecular biology, magnetic nanobeads play a key role in the separation and purification of DNA and RNA, which are necessary for procedures such as PCR. However, conventional magnetic nanobeads suffer from instability, aggregation, and poor surface functionality. The objective of this study was to synthesize and characterize graphene oxide (GO) -conjugated Fe3O4@SiO2 magnetic nanobeads for DNA isolation. The large surface area and functional groups of GO could bring about strong interactions with DNA, thus enhancing the binding and separation efficiency. Here, Fe3O4 nanoparticles are chosen as the core material because of the high magnetic saturation and biocompatibility. The silica shell can improve stability and serve as a platform for further functionalization. Amino functionalization of Fe3O4@SiO2 allows conjugation of GO at reactive sites. The stability and functionalization of the nanobeads were confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray fluorescence (XRF), particle size distribution, zeta potential, and electrophoretic mobility. The optimal GO to Fe3O4@SiO2-NH2 conjugation ratio (5:1) balanced adequate GO coverage and controllable particle dimension. The increased negative charge improved colloidal stability and reduced aggregation. The enhanced electrophoretic mobility ensures efficient separation of DNA. These findings highlight the potential of GO-conjugated Fe3O4@SiO2 magnetic nanobeads as promising tools for advanced DNA separation techniques.