Synthesis and characterization of multi-functional nanoparticles possessing magnetic, up-conversion fluorescence and bio-affinity properties
Synthesis and characterization of multi-functional nanoparticles possessing magnetic, up-conversion fluorescence and bio-affinity properties
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DOI：
10.1039/b315103d
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发表时间：
2004-01-01
影响因子：
--
通讯作者：
Cheng, J
中科院分区：
文献类型：
--
作者：
Lu, HC;Yi, GS;Cheng, J
合成并表征了具有磁性、上转换荧光和生物亲和特性的多功能纳米颗粒。颗粒具有核/壳结构。合成了直径5-15 nm的氧化铁纳米粒子作为磁芯。核心覆盖有镱和铒共掺杂氟化钇钠 (NaYF4:Yb,Er)，这是一种高效的红外到可见光上转换荧光粉。在 EDTA 和磁性纳米颗粒存在下，通过稀土金属盐与氟化物的共沉淀制备荧光粉壳。磁性/荧光杂化颗粒被SiO2包被并用戊二醛活化后，链霉亲和素被固定在颗粒上。通过透射电子显微镜发现磁性/荧光纳米颗粒是分散良好的球形颗粒，平均直径为68 nm。能量色散X射线微量分析和X射线荧光光谱都揭示了颗粒中铁的存在。在振动样品磁力计上进行的测量获得了粒子的强磁响应，荧光测量证明了其上转换特性。 X射线衍射分析表明，荧光粉壳与我们在之前的研究中制备的纯NaYF4：Yb，Er纳米颗粒具有相同的结构（G. S. Yi，H. C. Lu，S. Y. Zhao，Y. Ge，W. J. Yang，L. H.Guo，D.P. Chen和J. Cheng提交）。发现链霉亲和素包被的磁性/荧光颗粒与点有生物素化 IgG 的载玻片特异性结合并发射上转换荧光，证实了蛋白质的成功包被并保留了其光学活性和生物亲和力。
Multi-functional nanoparticles possessing magnetic, up-conversion fluorescence and bio-affinity properties were synthesized and characterized. The particles have a core/shell structure. Iron oxide nanoparticles of 5-15 nm diameter were synthesized as the magnetic core. The core was covered with ytterbium and erbium co-doped sodium yttrium fluoride (NaYF4:Yb,Er), an efficient infrared-to-visible up-conversion phosphor. The phosphor shell was prepared by co-precipitation of the rare-earth metal salts with fluoride in the presence of EDTA and the magnetic nanoparticle. After the magnetic/fluorescent hybrid particle was coated with SiO2 and activated with glutaraldehyde, streptavidin was immobilized on the particle. The magnetic/fluorescent nanoparticles were found by transmission electron microscopy to be well-dispersed spherical particles with an average diameter of 68 nm. Both energy dispersive X-ray microanalysis and X-ray fluorescence spectra revealed the existence of iron in the particle. Measurements performed on a vibrating sample magnetometer obtained a strong magnetic response for the particle and fluorescence measurements demonstrated its up-conversion property. X-Ray diffraction analysis suggests the phosphor shell has the same structure as the pure NaYF4: Yb, Er nanoparticles we prepared in a previous study (G. S. Yi, H. C. Lu, S. Y. Zhao, Y. Ge, W. J. Yang, L. H. Guo, D. P. Chen and J. Cheng, submitted). Streptavidin-coated magnetic/fluorescent particles were found to bind specifically to a glass slide spotted with biotinylated IgG and emit up-conversion fluorescence, confirming the successful coating of the protein and retention of its optical activity and bio-affinity.