论文总字数：22612字

摘 要

镧系元素为基础的上转换纳米颗粒，较为典型的有NaMF₄:Yb³ /Ln³ （M = Y或Gd，Ln = Er或Tm），它们均能吸收近红外的激发光将其转换为各种波长的短波长的发光，多色发光（目前常见的紫光、蓝光、红光、绿光等），所发射的波长范围可以从深紫外到近红外，上转换纳米粉末具有高的光化学稳定性、生物毒性小、较深的组织穿透能力、荧光寿命长、吸收和发射带都很狭窄以及可调的发射光波长和对自发荧光的抑制等特点吸引了来自于生物成像、治疗学、光电学等领域的研究者的关注，在生物方面具有广阔的前景，比如，可应用于生物传感、细胞amp;活体成像、肿瘤靶向成像（包括光动力治疗）、载药运输等多个医学领域。但是，一般上转换纳米粒子表面覆盖了一层疏水的配体，而体液的最主要的组成成分是水以及分散在水中的气体包括氧气和二氧化碳，还有各种无机离子包括钠离子、氯离子、钙离子、碳酸氢根离子、磷酸根离子，若直接将这种疏水的纳米粒子应用于生物体当中，将会产生聚沉，不能很好的分散，预期效果会大打折扣，因此阻碍了在生物方面的进一步应用。

尝试发展了几种制备水溶性上转换纳米颗粒（NaYF₄:Yb³ ,Er³ ）的方法。1.水热法制备表面配体为PEG的NaYF₄:Yb³ ,Er³ 纳米粒子，结果表明所制备的纳米粒子是纯立方相，980 nm激光照射下，肉眼观察到明亮的红光。可以很好的分散于水中。2.热共沉淀法制备的油酸配体包裹的NaYF₄:Yb³ ,Er³ 纳米粒子为纯六方相，粒径约20 nm，用1 mol/L盐酸处理后，纳米颗粒均匀分散在水中。3.在OA/ODE热共沉淀法制备NaYF₄:Yb³ ,Er³ 纳米粒子体系中加入了一定量PEG，结果表明，纳米颗粒表面配体中除了油酸根的存在，也有一部分PEG，提高了纳米粒子的水溶性。颗粒形貌为均一的六方片，颗粒尺寸直径约为60 nm，厚度为25 nm。

关键词：上转换纳米颗粒 水溶性 发光性能

Synthesis and Characterization of the Water-soluble

NaYF₄:Yb³ ,Er³ Nano-particles

Abstract

The upconversion of nanoparticles based on lanthanide，such as NaMF₄(M = Y or Gd, Ln = Er or Tm), all of which can convert near-infrared excitation to adjustable short-wave luminescence, and the wavelength ranges from deep ultraviolet to near infrared. It has the advantages of adjustable multicolor luminescence, excellent light stability, deep tissue penetration, small toxicity, long fluorescent lifetime, narrow absorption and emission bands, and tunable fluorescence emission wavelengths and suppression of auto-fluorescence and other characteristics. They attract from the biological imaging, therapeutics, optoelectronics and other fields The researcher's attention. Due to its versatility of multicolor light emission, excellent light stability, deep tissue penetration, toxicity, long fluorescent lifetime, absorption and emission bands are narrow and tunable fluorescence emission wavelengths and suppression of autofluorescence, It has a broad prospects in the biological aspects that it can be applied to biological sensing, cell imaging, in vivo imaging, tumor targeting imaging, drug transport and other fields. However, the general upconversion nanoparticles’ surface covered with a layer of hydrophobic ligand, and the body's main component of water and gas which dispersed in the water, including oxygen and carbon dioxide, there are a variety of inorganic ions, including sodium, chlorine Ions, calcium ions, bicarbonate ions, phosphate ions. If hydrophobic nanoparticles are applied in the organisms directly, precipitation will produce in the system, it can’t form a good dispersion, the expected effect will be greatly reduced. As a result, the further application in the biological aspects will be hindered.

Several methods of preparing water-soluble upconversion nanoparticles (NaYF₄: Yb³ , Er³ ) have been developed.1. NaYF₄: Yb³ , Er³ nanoparticles whose surface ligands are PEG-4000 were prepared by hydrothermal method. The results show that the prepared nanoparticles are pure cubic phase, and the bright yellow light is observed by the naked eye under 980nm laser irradiation. NaYF₄: Yb³ , Er³ /PEG

can be well dispersed in the water. 2. The NaYF₄: Yb³ , Er³ nanoparticles which are coated with oleic acid ligands are prepared by thermal coprecipitation method.The prepared nanoparticles are pure hexagonal phase with particle size of about 20nm. After being treated with 1mol/L hydrochloric acid, the nanoparticles were uniformly dispersed in water. 3. A certain amount of PEG-4000 was added to prepare NaYF₄: Yb³ , Er³ nanoparticles by OA/ODE thermal coprecipitation system. The results show that there are some PEG ligands together with oleic acid ligands on the surfaces of upconversion nanoparticles to make the particles water soluble. And the nanoparticles are uniform short hexagonal prisms with the diameter about 60nm and the height about 25 nm.

Keywords: Upconversion nanoparticles；Water soluble；Luminescence property

目录

摘要…………………………………………………………………………………Ⅰ

Abstract……………………………………………………………………………Ⅱ

目录…………………………………………………………………………………Ⅳ

第一章 绪论………………………………………………………………………1

1.1稀土上转换纳米粒子简介…………………………………………………1

1.2上转换纳米粒子组成及发光过程…………………………………………1

1.2.1上转换材料的组成…………………………………………………1

1.2.2发光机制……………………………………………………………2

1.3上转换纳米粒子的几种合成方法…………………………………………2

1.3.1 热分解法……………………………………………………………3

1.3.2水热（溶剂）热法……………………………………………………4

1.3.3热共沉淀法…………………………………………………………4

1.4上转换纳米粒子的表面修饰………………………………………………5

1.4.1亲水性改性…………………………………………………………5

1.4.2表面配体的氧化……………………………………………………6

1.4.3表面配体的交换……………………………………………………6

1.4.4表面包覆……………………………………………………………7

1.4.5双亲性（亲油和亲水）分子的改性………………………………7

1.5本论文研究内容……………………………………………………………8

第二章 实验过程与数据分析…………………………………………………9

2.1实验原料与仪器……………………………………………………………9

2.1.1实验原料……………………………………………………………9

2.1.2实验仪器……………………………………………………………9

2.2利用PEG为表面配体水热法制备NaYF₄:18%Yb³ ,2%Er³ ……………10

2.2.1 实验过程……………………………………………………………10

2.2.2实验结果……………………………………………………………10

2.3合成油酸配体包裹的NaYF₄:18%Yb³ ,2%Er³ 以及酸处理去除油酸……12

2.3.1实验过程……………………………………………………………12

2.3.2实验结果……………………………………………………………13

2.4合成油酸与PEG两种配体相竞争与协调的NaYF₄:18%Yb³ ,2%Er³ …15

2.4.1实验过程……………………………………………………………15

2.4.2实验结果……………………………………………………………16

第三章 结论与展望……………………………………………………………19

3.1结论………………………………………………………………………………19

3.2展望………………………………………………………………………………19

参考文献…………………………………………………………………………20

致谢…………………………………………………………………………………23

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