title: Synthesis of size-controlled Fe3O4@SiO2 magnetic nanoparticles for nucleic acid analysis.
abstract: We present a systematic study on the preparation, characteration and potential application of Fe3O4 and Fe3O4@SiO2 nanoparticles. Fe3O4 nanoparticles of controllable diameters were successfully synthesized by solvothermal system with tuning pH. The magnetic properties of nanoparticles were measured by vibration sample magnetometer. Fe3O4@ SiO2 nanoparticles were obtained via classic Stöber process. Streptavidin coated Fe3O4@SiO2 nanoparticles were prepared by covalent interaction. The quantity of streptavidin bound to nanoparticles was determined by UV-Vis spectrometer. To evaluate the binding efficiency and capacity of nucleic acid on nanoparticles, the capture of biotinylated oligonucleotide on streptavidin coated Fe3O4@SiO2 nanoparticles at different concentration was estimated by fluorescence detection. Both Fe3O4 and Fe3O4@SiO2 nanoparticles exhibited well crystallization and magnetic properties. The maximal amount of streptavidin immobilized onto the Fe3O4@SiO2 nanoparticles was 29.3 microg/mg. The saturation ratio of biotinylated oligonucleotides captured on streptavidin coated Fe3O4@SiO2 nanoparticles was 5 microM/mg within 20 minutes, indicating that FeO4@SiO2 nanoparticles immobilized by streptavidin were excellent carriers in nucleic acid analysis due to their convenient magnetic-separation property. Therefore, the synthesized Fe3O4 and Fe3O4@SiO2 nanoparticles with controllable size and high magnetic saturation have shown great application potentials in nucleic acid research.
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Nanjing 210096, China.
authors.forename: Huanxiang
authors.initials: H
authors.lastname: Sun
authors.forename: Xin
authors.initials: X
authors.lastname: Zeng
authors.forename: Ming
authors.initials: M
authors.lastname: Liu
authors.forename: Sauli
authors.initials: S
authors.lastname: Elingarami
authors.forename: Guopeng
authors.initials: G
authors.lastname: Li
authors.forename: Bin
authors.initials: B
authors.lastname: Shen
authors.forename: Nongyue
authors.initials: N
authors.lastname: He
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D058185:Magnetite Nanoparticles / Q000032:analysis* / Q000737:chemistry*; D008422:Materials Testing; D009696:Nucleic Acids / Q000032:analysis* / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D058185:Magnetite Nanoparticles; D009696:Nucleic Acids; D012822:Silicon Dioxide