【摘要】 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.更多还原

【Abstract】 The magnetic-fluorescent CdTe@Fe3O4 multifunctional nanoparticles, which combined both magnetic and fluorescent properties in one entity, were currently prepared with layer-by-layer (LBL) self-assembly process, and their properties and applications were investigated and discussed. Nano-sized magnetic Fe3O4 was firstly prepared by co-precipitation method in aqueous phase with NaOH as precipitator under the optimum conditions of 50 ℃, mol ratio of Fe2+ to Fe3+ as 1∶2 for 30 min, and then was surface modified with 1, 6-hexylenediamime. The average size of the particles prepared by the method was about 10 nm observed through transmission electron microscopy (TEM). The core-shell mag-netic quantum dots (mQDs), i. e. CdTe@Fe3O4, were prepared by LBL method with Fe3O4 nanoparticles as core. The re-sults indicated that the qualified mQDs could be achieved under the optimum conditions when mol ratio of Fe3O4 to CdTe was 1∶3, pH value was 6.0, and reactant solution was refluxed for 30 min at 30 ℃. The obtained mQDs were character-ized by TEM, ultraviolet spectrum (UV), and fluorescence spectrum (FS), respectively. TEM image indicated that 12—15 nm of mQDs were obtained, and FS and UV data showed red shift of maximum emission wavelength from 530 nm to 570 nm and the maximum absorbance wavelength from 530 nm to 535 nm respectively, which inferred the successful formation of CdTe shell on the surface of magnetic Fe3O4 core. The synthesized mQDs can be conveniently applied in DNA’s label-ing, sensing, and separating processes.更多还原