DNA purification is considered to be a critical step in biomedical applications such as genetic therapy and clinical diagnosis. These years, the magnetic silica beads are widely used in DNA purification due to the advantages of averting the use of some toxic organic solvents and being easy to auto-magnetic separation. Among them, magnetic Fe3O4@SiO2 nanoparticles (NPs) were widely used because of their stability, monodispersity, selectivity, and high separation efficiency in magnetic field. However, the shape and structure of particles may affect the DNA isolation efficiency, such as the DNA adsorption capacity and recovery rate. It has not yet been fully explored. In this work, a series of Fe3O4 NPs with different core diameters were synthesized firstly by co-precipitation and hydrothermal methods, and then further coated by silica through St?ber method. The resultant Fe3O4@SiO2 NPs were characterized by SEM, TEM, IR and BET, respectively. The DNA adsorption capacity of Fe3O4@SiO2 NPs were studied by UV?Vis, and the magnetic separation properties were also determined by magnetic response time. The results showed that in the range of 20?750 nm of particle size, the larger size particles could provide more unit planar binding sites when combining with DNA, which increased the combination stability and binding probability. Thus, the DNA binding capacity of the particles increased with the increase of particles size. In addition, the magnetic response time of Fe3O4@SiO2 NPs with different core?shell structures were also different. When the size of the core was similar, the thicker SiO2 shell around would weaken the dipole?dipole interactions between particles and reduce particles aggregation, thus the magnetic response time of NPs increased, leading to a low recovery rate within a limited operating time. Comparing the DNA adsorption capacity and recovery efficiency of particles. The Fe3O4@SiO2 NPs around 200 nm was the optimal choice for blood DNA purification, which had high recovery rate (95.2%) in a short magnetic response time (10 s).
Huifang XING Liangrong YANG Jiemiao YU Huizhou LIU Hao YU Wanbo LI Shuidong CUI
. Effect of magnetic Fe3O4@SiO2 nanoparticles structure on its adsorption to DNA[J]. The Chinese Journal of Process Engineering, 2018
, 18(6)
: 1119
-1125
.
DOI: 10.12034/j.issn.1009-606X.218234
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