Three generations of magnetic and luminescent dendrimer microspheres were prepared. Superpara-magnetic Fe3O4 nanoparticles were first prepared by hydrothermal coprecipitation of ferric and ferrous ions, followed by the modification of their surfaces with dendrimers. The surface-modified Fe3O4 nanoparticles were then linked to CdSe/CdS quantum dots( QDs), which were modified with thioglycolic acid to form the Fe3O4/ CdSe/CdS fluorescent magnetic nanocomposites through the adsorption and bonding of the amino groups on the surfaces of Fe3O4 and the carboxyl groups on CdSe/CdS QDs. The structure and properties of the nanocomposites were characterized by Fourier transform infrared spectrometer(FTIR) , elemental analysis(EA), transmission electron microscope(TEM) , energy dispersive spectrometer( EDS) , vibrating sample magnetometer ( VSM) , photoluminescence(PL) and UV-Vis spectrameters. The results show that the average size of three generations of nanocomposites are 15, 34 and 49 nm, respectively, the fluorescence property of GIF is the best with a fluorescent quantum yield up to 24. 1% , while the magnetic property of GOF is the optimal with a · saturation magnetization of 15. 96 A · m /kg. The synthesized bifunctional nanocomposites are expected to be widely used in immune detection, luminescence detection, targeted therapy, magnetic separation and so on.%采用化学共沉淀法,以FeCl3·6H2O和FeSO4·7H2O为原料制备了磁性Fe3O4纳米颗粒,采用树状大分子对其进行修饰,然后通过树状大分子具有的大量空腔及末端丰富的氨基,经吸附、键合,与大量巯基乙酸修饰的CdSe/CdS量子点连接,得到三代具有荧光磁性双功能的树状分子微球,并对其进行结构表征与性能测试.结果表明:三代复合后的微球的平均粒径分别为15,34和49nm;一代荧光磁性微球的发光性能最佳,其量子产率达24.1％；零代荧光磁性微球磁性能最优,其饱和磁化强度为15.96 A·m2/kg.这种具有荧光和磁性的双功能纳米复合微粒有望在免疫检测、靶向治疗、荧光追踪和磁性分离等方面得到广泛应用.
展开▼
