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本文通过层层自组装技术(layer-by-layer,LBL)成功制备了CdTe@Fe3O4磁性荧光复合纳米粒子,并对其特性和应用进行了讨论.首先,采用化学共沉淀法,以NaOH为沉淀剂,Fe2+和Fe3+物质的量的比为1∶2,在50℃水相中电磁搅拌30min,制备出具有磁性的纳米Fe3O4,然后表面修饰1,6-己二胺.通过透射电镜(transmission electron microscopy,TEM)对其进行观察,粒径在10nm左右.核壳CdTe@Fe3O4复合功能纳米粒子的合成表明:Fe3O4和CdTe物质的量的比为1∶3,pH=6.0,温度30℃,反应时间30min为其最佳合成条件.通过TEM、紫外和荧光光谱对合成的纳米粒子分别进行了表征.CdTe@Fe3O4粒径在12~15nm,最大发射波长从530nm红移到570nm,而最大吸收波长则从530nm红移到535nm.结果表明,磁性Fe3O4表面成功覆盖了CdTe壳层.核壳型CdTe@Fe3O4磁性荧光复合纳米粒子的应用能够实现对DNA进行简便快捷的标记、传感和分离.
In this paper, CdTe @ Fe3O4 magnetic fluorescence composite nanoparticles were prepared successfully by layer-by-layer (LBL) technique, and their properties and applications were discussed.First, using chemical coprecipitation method, NaOH as precipitation Agent, Fe2 + and Fe3 + was 1: 2, the magnetic nano-Fe3O4 was prepared by magnetic stirring in water phase at 50 ℃ for 30min, and then the surface was modified with 1,6-hexanediamine.The results of transmission electron microscopy microscopy and TEM), the particle size was about 10nm.The synthesis of core-shell CdTe @ Fe3O4 composite functional nanoparticles showed that the molar ratio of Fe3O4 to CdTe was 1: 3, pH = 6.0, temperature was 30 ℃, reaction 30 min for the best synthesis conditions.The synthesized nanoparticles were characterized by TEM, UV and fluorescence spectroscopy respectively.CdTe @ Fe3O4 particle size of 12 ~ 15nm, the maximum emission wavelength red-shifted from 530nm to 570nm, and the maximum absorption wavelength Red shift from 530nm to 535nm.The results show that the magnetic Fe3O4 surface successfully covered the CdTe shell.The application of the core-shell CdTe @ Fe3O4 magnetic fluorescence composite nanoparticles can be easily and quickly labeled, sensed and isolated DNA.