中文摘要：

采用液相法成功制备了MWCNTs负载NaGdF4∶Tb^3＋,Eu^3＋纳米粒子的磁光热多功能复合纳米材料,并用XRD,SEM和EDS对其结构、组成和形貌进行了表征,结果表明：NaGdF4∶Tb^3＋,Eu^3＋纳米粒子为六方晶相,形貌为球形且尺寸分布均匀,直径大约为25 nm,并且均匀的包覆在MWCNTs的表面;通过PL,VSM和HTC对复合纳米材料的发光性能,磁性能和光热转换性能进行了表征,采用MTT法对多功能复合纳米材料的生物相容性进行了评估,结果表明：MWCNTs-NaGdF4∶Tb^3＋,Eu^3＋复合纳米材料具有良好的多色发光性能、磁性能、光热转换性能、低的毒性和良好的生物相容性。该种磁光热多功能复合纳米材料在生物标记、生物成像、肿瘤诊疗等领域有着广泛的应用前景。

英文摘要：

A novel multicolor luminescence-magnetic-thermal multifunctional hybrid nanomaterial has been successfully prepared by coating the NaGdF4∶Tb^3＋,Eu^3＋nanoparticles on the surface of MWCNTs. The structure,morphology and composition of the samples were confirmed by XRD, SEM, and EDS spectrum. XRD patterns show that NaGdF4∶Tb^3＋,Eu^3＋crystal is hexagonal phase, and the MWCNTs and NaGdF4∶Tb^3＋,Eu^3＋are coexistent in the nanocomposites. SEM images indicate that the NaGdF4∶Tb^3＋,Eu^3＋nanoparticles are close to spherical in shape and the sizes are relatively uniform with a mean diameter of 25 nm. They are successfully coated on the surface of MWCNTs. The luminescence, magnetic, thermal properties and biocompatibility were characterized by PL,VSM, HTC and MTT assay, respectively. Under the excitation of UV light, the as-prepared NaGdF4∶Tb^3＋ and NaGdF4∶Eu^3＋ exhibit strong green and red emission. The multicolor emission can be realized from green to red by adjusting the doped concentration of Tb^3＋ and Eu^3＋ions. The obtained products also present paramagnetic property at room temperature and photothermal transduction properties. In vitro cell cytotoxicity assays on Hep-2 cancer cells demonstrate that the nanocomposites exhibit low toxicity and good biocompatibility. Taken together, the multifunctional hybrid nanocomposites have preferably magnetism, luminescence and photothermal properties, as well as excellent biocompatibility, which have great promise applications such as biological labeling,photothermal therapy, bioimaging and so on.