Sun Huanxiang, Zeng Xin, Liu Ming, Elingarami Sauli, Li Guopeng, Shen Bin, He Nongyue
School of Chemistry and Chemical Engineering, Southeast University, Nanjing 210096, China.
J Nanosci Nanotechnol. 2012 Jan;12(1):267-73. doi: 10.1166/jnn.2012.5170.
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.
我们对Fe3O4和Fe3O4@SiO2纳米粒子的制备、表征及潜在应用进行了系统研究。通过调节pH值的溶剂热体系成功合成了直径可控的Fe3O4纳米粒子。用振动样品磁强计测量了纳米粒子的磁性。通过经典的Stöber法获得了Fe3O4@SiO2纳米粒子。通过共价相互作用制备了链霉亲和素包被的Fe3O4@SiO2纳米粒子。用紫外可见光谱仪测定了与纳米粒子结合的链霉亲和素的量。为了评估核酸在纳米粒子上的结合效率和容量，通过荧光检测估计了不同浓度下生物素化寡核苷酸在链霉亲和素包被的Fe3O4@SiO2纳米粒子上的捕获情况。Fe3O4和Fe3O4@SiO2纳米粒子均表现出良好的结晶性和磁性。固定在Fe3O4@SiO2纳米粒子上的链霉亲和素的最大量为29.3微克/毫克。在20分钟内，链霉亲和素包被的Fe3O4@SiO2纳米粒子捕获的生物素化寡核苷酸的饱和率为5微摩尔/毫克，这表明链霉亲和素固定的FeO4@SiO2纳米粒子因其方便的磁分离特性在核酸分析中是优异的载体。因此，合成的尺寸可控且磁饱和度高的Fe3O4和Fe3O4@SiO2纳米粒子在核酸研究中显示出巨大的应用潜力。
