【摘要】 利用改良的Stber法合成CdTe@SiO₂微球,直接沉淀法制备CdTe@SiO₂@GdF₃核壳结构的荧光/磁共振成像双功能微球,并用透射电镜（TEM）、能量散射X射线光谱（EDXA）、磁共振成像（MRI）、Fourier变换红外光谱（FT-IR）和荧光光谱等方法对其结构、磁共振成像和发光性能进行表征.实验结果表明:合成的微球具有明显的球形核壳结构,大量的GdF₃以小颗粒形态均匀分散于SiO₂表层,颗粒尺寸为5⁸nm;在CdTe@SiO₂@GdF₃微球表面可检测到Si,O和Gd元素,即Gd已掺杂到CdTe@SiO₂材料中;相对于CdTe量子点,CdTe@SiO₂@GdF₃微球荧光发射光谱发生红移,但仍具有良好的荧光性能;CdTe@SiO₂@GdF₃微球的弛豫参数r1=3.48s^-1/(mmol·L^-1),即合成的CdTe@SiO₂@GdF₃微球可用于T1-加权磁共振成像;当CdTe@SiO₂@GdF₃溶液的质量浓度为200μg/mL时,细胞活力仍大于90%,即该微球对细胞的毒性作用较弱.更多还原

【Abstract】 CdTe@SiO₂ microspheres were synthesized by modified Stber method,and then CdTe@SiO₂@GdF₃ fluorescence/magnetic resonance imaging dual functional microsphere with core/shell structure were prepared by direct precipitation method.Furthermore the structure, magnetic resonance imaging and fluorescence property were characterized by transmission electron microscope（TEM）,energy dispersive X-ray analysis（EDXA）,magnetic resonance imaging（MRI）,Fourier transform infrared spectroscopy（FT-IR）and fluorescence spectrum.The experimental results show that the synthesized microsphere has obvious spherical core/shell structure,a large number of GdF₃ dispersed well on the surface of silica in the form of small particles,and the particle sizes are 5—8 nm.Si,O and Gd elements can be detected on the surface of CdTe@SiO₂@GdF₃ microsphere,and Gd has been doped into the CdTe@SiO₂ materials.Compared with CdTe quantum dots,the fluorescence emission spectra of CdTe@SiO₂@GdF₃ microspheres have a red shift,but still have good fluorescence property.The relaxation parameter r1 of CdTe@SiO₂@GdF₃ microspheres is 3.48 s^-1/(mmol·L^-1),so the synthesized CdTe@SiO₂@GdF₃ microspheres can be used for T1-weighted magnetic resonance imaging.When mass concentration of CdTe@SiO₂@GdF₃ is 200μg/mL,the cell viability is still above 90%,indicating that the toxicity of the microphere on cells is weak.更多还原