【作者】 汪乐余；

【导师】 李亚栋；

【作者基本信息】 清华大学 ， 化学， 2007， 博士

【摘要】 稀土掺杂发光纳米材料在发光器件、太阳能电池、生物标记、激光防伪等领域有着广泛的应用前景。而磁性纳米材料在磁存储、磁生物分离、磁靶向给药、磁共振成像等领域具有重要的应用价值。发展制备这些材料的新方法,不仅具有重要的理论研究价值,而且具有重要的现实意义。论文主要围绕“稀土掺杂发光纳米晶和磁性氧化物纳米晶的合成、表征与应用”开展系列研究工作。利用溶剂热技术制备了尺寸可调的立方相和六方相NaYF4: Yb3+-Er3+亲水性发光纳米球。发展了一种制备上转换荧光性能更好的六方相NaYF4纳米晶的新方法。并对纳米晶进行了表面功能化修饰,将其用作上转换荧光生物标记,成功用于亲和素和核酸的定量分析。基于纳米晶独特的上转换荧光,发展了一种简单、快速、灵敏的生物检测新方法。通过引入1,6-己二胺为氨基功能化试剂,在不加任何表面活性剂的情况下,利用溶剂热技术,成功发展了一种制备表面带有氨基官能团、在水溶液中分散性好、尺寸可调的Fe3O4的纳米粒子和空心纳米球的新方法。并将所制备的磁性纳米晶用于免疫分析中的抗体磁分离和大白鼠肝脏的磁共振成像研究。为制备生物应用的磁性纳米材料提供了新思路。通过溶剂热技术,合成了结晶度高、分散性好的LaF3:Ce3+/Tb3+发光纳米晶。并将其用作荧光共振能量转移的能量给体,成功地用于水溶液中葡萄糖的灵敏、快速检测。发展了一种新的荧光共振能量转移检测新方法。以氨基功能化的SiO2纳米球为模板,利用模板表面的氨基,诱导水杨酸与稀土离子在模板表面沉积,得到配合物薄层覆盖的发光纳米球。发展了一种制备配合物纳米材料的新方法。利用水对其荧光的淬灭效应,成功地将其用于溶液中痕量水的检测。发展了一种简单、灵敏、快速测定溶液中水含量的新方法。在油-水混合体系中,利用溶剂热技术,成功合成了结晶度高、分散性好的LaF3、NaYF4、NaLaF4和CdS、ZnS单晶纳米棒。发展了一种通过有效控制单体浓度来制备单分散纳米棒的新方法。通过掺杂不同的稀土离子,纳米晶能发射不同颜色的上、下转换荧光,并研究了纳米晶的荧光性质。利用乳液包覆的技术,将油相中分散的纳米晶成功转移到水相,进行了初步的细胞荧光成像研究,为生物应用打下了基础。更多还原

【Abstract】 Lanthanide-doped luminescent nanomaterials have great potentials in the field of optical devices, solar cells, biological labels, and anticounterfeiting applications. Meanwhile, magnetic nanomaterials have also been widely used in the filed of magnetic memory, drug and gene delivery, bioseparation, and magnetic resonance imaging. Developing new synthetic technologies for these nanomaterials is very important to both fundamental research and practical application. Surrounding the rare-earth-doped fluoride and magnetic oxide nanocrystals, this dissertation presents a systematic research about their preparation, characterization and application.Based on the solvothermal technology, a facile method was developed to prepare hydrophilic NaYF4:Yb3+-Er3+ nanospheres with controllable sizes. By prolonging the reaction time, the cubic phase nanocrystals transferred into hexagonal phase nanocrystals that can emit stronger green upconversion fluorescence. These luminescent nanocrystals were functionalized with biotin and nucleic acids and used as biolabels for the determination of avidin and DNA. Based on their novel upconversion luminescence, a facile, rapid and sensitive biological determination method was successfully developed.With 1,6-hexanediamine as amine-functionalization reagent, a facile one-pot strategy was put forward to prepare amine-functionalized magnetite nanoparticles and hollow nanospheres with excellent magnetism, tunable sizes, good dispersibility and crystallinity. These hydrophilic nanocrystals were used for the magnetic bioseparation of antibody in immunoassay and as contrast agents in MRI. The results indicate that this work provide a novel viewpoint for the preparation of bioapplication nanomaterials.Luminescent LaF3:Ce3+/Tb3+ single nanoparticles were prepared by using a facile, solvothermal strategy. Thereafter, these highly luminescent nanocrystals were functionalized with glucose and used as energy donor for the glucose fluorescence resonance energy transfer (FRET) determination. By using amine-functionalized SiO2 nanospheres as supporting templates, the metal-organic coordination compound (SiO2-NH2@SA-La3+/Tb3+) luminescent nanospheres were successfully prepared. Based on their strong fluorescence and the optical sensibility to water, a sensitive and rapid fluorescence method has been developed for the determination of water in liquid. It is believable that the fabrication of this luminescent nanosphere will be a great potential model for other metal-organic coordination compound nanospheres. In addition, the fluorescence determination method demonstrated here represents a simple and potentially useful technique for the rapid and sensitive determination of water in liquid.In the water-oleic acid mixture system, a novel solvothermal technology was developed to fabricate LaF3, NaYF4, NaLaF4, CdS and ZnS single-crystal nanorods with nearly uniform size. By doping different rare-earth ions, the nanorods can emit different color downcoversion and upconversion fluorescence. For the next bioapplication as fluorescent biolabels, these luminescent nanocrystals were successfully transferred into aqueous solution from nonpolar surfactants with a microemulsion technology. Their applications in fluorescence imaging as cell labels are undergoing and some results have been successfully obtained.更多还原