通过异质核诱导,利用溶剂热法在较低温度下合成了具有疏水表面的上转换发光稀土核-壳NaYF4/NaLuF4∶20%Yb,1%Tm纳米粒子,并利用X射线衍射仪、透射电子显微镜、傅里叶变换红外吸收光谱仪以及荧光光谱仪等测试设备对其进行了结构、形貌和上转换光谱的表征.测试结果表明,纳米粒子核为立方相,壳层为六角相.核-壳型纳米粒子的尺寸平均在20 nm以下,分布较为均匀.在980 nm近红外光激发下,核-壳型纳米粒子发射出较强的紫色和紫外荧光,且发光强度明显高于同尺寸立方相NaLuF4∶20%Yb,1%Tm纳米粒子.这表明利用异质核诱导的方法制备的核-壳型纳米粒子在生物医学领域具有更高的应用价值.

utilizing cubic NaYF4 nanoparticles as cores,we synthesized hydrophobic core-shell α-NaYF4/β-NaLuF4∶20%Yb,1%Tm upconversion nanoparticles under a mild solvothermal condition.The core-shell nanoparticles were characterized by X-ray diffraction,transmission electron microscopy,Fourier transform infrared spectrometer and fluorescence spectrometer.The measurement results showed that α-NaYF4 cores were about 10-15 nm,and average size of α-NaYF4/β-NaLuF4∶20%Yb,1%Tm upconversion nanoparticles was about 20 nm.Both the core and core-shell nanoparticles possessed narrow size distributions.The core-shell nanoparticles showed stronger luminescence intensity than those of cubic NaLuF4∶20%Yb,1%Tm with similar size.The detection results showed that this kind of hydrophobic core-shell α-NaYF4/β-NaLuF4∶20%Yb,1%Tm nanoparticle has a higher potential value in biomedical applications.