Cheng Yuan, Sun Kangning
Appl Opt. 2017 Jun 10;56(17):4905-4910. doi: 10.1364/AO.56.004905.
Core-shell structured SiO@YVO:Yb, Er, Eu nanospheres were prepared by a simple solgel method followed by a subsequent heat treatment. The as-prepared composites were characterized by a scanning electron microscope, high-resolution transmission electron microscope, x-ray diffraction, and photoluminescence spectra. The influences of different coating numbers were also studied. To sum up, the composites are spherical shaped with an average diameter of 200 nm, and the YVO:Yb, Er, Eu luminescent particles are successfully coated on the surface of SiO nanospheres. Under the near-infrared irradiation at 980 nm, the composites can emit strong green lights (at 525 nm, 550 nm) attributed to the H2→I4, S4→I4 transitions of Er ions, and slight red lights (at 590 nm, 620 nm) attributed to the D5→F7, D5→F7 transitions of Eu ions. Given the above, due to the regular core-shell structure, the uniform distribution of nanoparticles, and the colorful emissions, the SiO@YVO:Yb, Er, Eu nanospheres may have great potential for some biological applications, such as biological tracers, bio-labeling, and so on.
通过简单的溶胶-凝胶法并随后进行热处理制备了核壳结构的SiO@YVO:Yb、Er、Eu纳米球。采用扫描电子显微镜、高分辨率透射电子显微镜、X射线衍射和光致发光光谱对所制备的复合材料进行了表征。还研究了不同包覆层数的影响。综上所述，复合材料呈球形，平均直径为200 nm，YVO:Yb、Er、Eu发光颗粒成功包覆在SiO纳米球表面。在980 nm近红外光照射下，复合材料可发射出归因于Er离子的H2→I4、S4→I4跃迁的强绿光（525 nm、550 nm）以及归因于Eu离子的D5→F7、D5→F7跃迁的微弱红光（590 nm、620 nm）。鉴于上述情况，由于具有规则的核壳结构、纳米颗粒的均匀分布以及多彩的发射，SiO@YVO:Yb、Er、Eu纳米球在一些生物应用中可能具有巨大潜力，如生物示踪剂、生物标记等。
