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

Abstract

Magnetic Fe3O4nanoparticles were prepared by coprecipitation and then coated with silica. These Fe3O4/SiO2nanoparticles consisted of a 10–15 nm magnetic core and a silica shell of 2–5 nm thickness. The superparamagnetic property of the Fe3O4/SiO2particles with the magnetization of 42.5 emu/g was confirmed by vibrating sample magnetometer (VSM). We further optimized buffers with these Fe3O4/SiO2nanoparticles 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 ofSgene 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/SiO2nanoparticles was superior to that obtained with commercialized Fe3O4/SiO2microparticles, 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/SiO2nanoparticles was significantly reduced as the particles were attracted to magnets more quickly (15–20 s) than the commercialized microparticles (2-3 min).

Nanoparticles: synthesis and applications

“…Quy et al (2013) have shown that the purification efficiency of DNA of both EBV and HBV using synthesized silica-coated Fe 3 O 4 MNPs was superior to that obtained with commercialized silica-coated Fe 3 O 4 magnetic microparticles. Quy et al (2013) reported also on time saving in detection of EBV and HBV, namely the time required for DNA purification using silica-coated Fe 3 O 4 nanoparticles was significantly reduced as the particles were attracted to magnets more quickly (15À20 seconds) than the commercialized silica-coated Fe 3 O 4 microparticles (about 2À3 minutes). These results were attributed to the fact that silica-coated Fe 3 O 4 nanoparticles have a larger total surface area compared to that of the commercialized silica-coated Fe 3 O 4 microparticles.…”

“…Several methods can be listed as precipitation: coprecipitation, microemulsion/inverse microemulsion, polyol, etc. Coprecipitation is a convenient way to synthesize Fe 3 O 4 nanoparticles (Lu et al, 2007;Quy et al, 2013;Dung et al, 2016;Khalil, 2015;Mascolo et al, 2013). The mixture of two chloride salts of FeCl 2 and FeCl 3 with 1:2 molar ratios of Fe 21 /Fe 31 was vigorously stirred and kept at 70 C before NH 4 OH was added resulting in the black color precipitation.…”

“…The surfaces of silica-coated MNPs are hydrophilic, and are readily modified with other functional groups (Ulman, 1996). Quy et al (2013) and Hieu et al (2017) have prepared Fe 3 O 4 /SiO 2 nanoparticles by coating MNPs with silica using TEOS.…”

“…Ashtari et al (2005) reported a method for recovery of target ssDNA using amino-modified silica-coated MNPs and used them to recover trace concentrations of target ssDNA fragments of severe acute respiratory syndrome virus with high efficiency and good selectivity. Quy et al (2013) presented a method for synthesis of the silica-coated Fe 3 O 4 MNPs and their application for isolation and enrichment of DNA of EpsteinÀBarr virus (EBV), which is associated with particular cancers and lymphoma, and hepatitis virus type B (HBV) which causes hepatitis. Quy et al (2013) have shown that the purification efficiency of DNA of both EBV and HBV using synthesized silica-coated Fe 3 O 4 MNPs was superior to that obtained with commercialized silica-coated Fe 3 O 4 magnetic microparticles.…”

“…Quy et al (2013) presented a method for synthesis of the silica-coated Fe 3 O 4 MNPs and their application for isolation and enrichment of DNA of EpsteinÀBarr virus (EBV), which is associated with particular cancers and lymphoma, and hepatitis virus type B (HBV) which causes hepatitis. Quy et al (2013) have shown that the purification efficiency of DNA of both EBV and HBV using synthesized silica-coated Fe 3 O 4 MNPs was superior to that obtained with commercialized silica-coated Fe 3 O 4 magnetic microparticles. Quy et al (2013) reported also on time saving in detection of EBV and HBV, namely the time required for DNA purification using silica-coated Fe 3 O 4 nanoparticles was significantly reduced as the particles were attracted to magnets more quickly (15À20 seconds) than the commercialized silica-coated Fe 3 O 4 microparticles (about 2À3 minutes).…”