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Journal of Nanomaterials
Volume 2013 (2013), Article ID 603940, 6 pages
Research Article

Synthesis of Silica-Coated Magnetic Nanoparticles and Application in the Detection of Pathogenic Viruses

1Key Laboratory for Enzyme and Protein Technology, VNU University of Science, 334 Nguyen Trai, Thanh Xuan, Hanoi, Vietnam
2VNU University of Science, 334 Nguyen Trai, Thanh Xuan, Hanoi, Vietnam
3Nano and Energy Center, Vietnam National University, 334 Nguyen Trai, Thanh Xuan, Hanoi, Vietnam
4Hospital 103, 104 Phung Hung, Ha Dong, Hanoi, Vietnam

Received 29 March 2013; Revised 6 June 2013; Accepted 10 June 2013

Academic Editor: Subhankar Bedanta

Copyright © 2013 Dao Van Quy et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Magnetic Fe3O4 nanoparticles were prepared by coprecipitation and then coated with silica. These Fe3O4/SiO2 nanoparticles consisted of a 10–15 nm magnetic core and a silica shell of 2–5 nm thickness. The superparamagnetic property of the Fe3O4/SiO2 particles with the magnetization of 42.5 emu/g was confirmed by vibrating sample magnetometer (VSM). We further optimized buffers with these Fe3O4/SiO2 nanoparticles to isolate genomic DNA of hepatitis virus type B (HBV) and of Epstein-Barr virus (EBV) for detection of the viruses based on polymerase chain reaction (PCR) amplification of a 434 bp fragment of gene specific for HBV and 250 bp fragment of nuclear antigen encoding gene specific for EBV. The purification efficiency of DNA of both HBV and EBV using obtained Fe3O4/SiO2 nanoparticles was superior to that obtained with commercialized Fe3O4/SiO2 microparticles, as indicated by (i) brighter PCR-amplified bands for both HBV and EBV and (ii) higher sensitivity in PCR-based detection of EBV load (copies/mL). The time required for DNA isolation using Fe3O4/SiO2 nanoparticles was significantly reduced as the particles were attracted to magnets more quickly (15–20 s) than the commercialized microparticles (2-3 min).