Ag/稀土有机框架纳米复合物的构筑及其上转换发光增强

As a new multifunctional nano-diagnostic and therapeutic agent, rare earth upconversion nanocrystals have brought new opportunities and challenges for early diagnosis and treatment of disease due to their deeper penetration depth of near infrared light, less damage to biological tissue, good luminescent monochromaticity, long luminescence lifetime, and so on. This project aims to combine the upconversion luminescence properties of rare earth ions with the advantages of metal organic framework nanocrystals (such as large specific surface area, high porosity, and orderly controlled structures), and prepare the Ag/rare earth organic framework nanocomposites with upconversion luminescence. It is expected to reduce the local lattice vibration energy of materials and the nonradiative transition probability of rare earth irons, and enhance the upconversion luminescence efficiency of rare earth organic framework nanocrystals by selecting appropriate organic ligands and using the surface plasmon resonance effect of Ag nanocrystals. By the way of surface modification, it makes the Ag/rare earth organic framework nanocomposites have good water stability and biocompatibility, which will be used for the controlled release of anticancer drugs and upconversion luminescence tracer. In order to enhance the enrichment of anticancer drugs in the tumor site, the effects of morphology and pore structure of Ag/rare earth organic framework nanocomposites on the circulating time and tissue distribution of the drug in vivo will be investigated. Multifunctional nano-diagnostic and therapeutic agent, that has the functions of drug targeted delivery, controlled release and luminescence tracer, will be provided for clinical diagnosis and treatment.

稀土上转换纳米晶作为一种新型多功能纳米诊疗剂，具有较深的光穿透深度、对生物组织几乎无损伤、发光单色性好和发光寿命长等优点，为疾病早期诊断和治疗带来了新的机遇和挑战。本项目拟结合稀土离子上转换发光特性和金属有机框架纳米晶比表面积大、孔隙率高以及结构有序可控等优点，构筑具有上转换发光功能的Ag/稀土有机框架复合纳米晶。以期能够通过选择合适的有机配体减小材料局域晶格振动能量、降低稀土离子无辐射跃迁几率，利用Ag纳米晶表面等离子体共振效应，提高稀土有机框架纳米晶的上转换发光效率。通过表面修饰等手段，使Ag/稀土有机框架复合纳米晶具有良好的水稳定性和生物相容性，用于抗癌药物可控靶向释放和上转换发光示踪。研究不同形貌和孔结构的Ag/稀土有机框架复合纳米晶对药物在生物体内循环时间和药物组织分布的影响，提高抗癌药物在肿瘤部位富集，为临床诊断和治疗提供兼具药物靶向输送、控制释放和发光示踪的多功能纳米诊疗剂。

稀土纳米材料应用关键是提高材料的荧光量子效率。本项目中，针对申请书研究目标1，我们制备出一系列稀土MOFs荧光材料及其复合物，提高了材料的发光效率，解决了“高质量稀土纳米发光材料的制备问题”。针对申请书研究目标2，我们系统地研究了稀土离子的发光性质与材料的依赖关系，借助于密度泛函理论和MATLAB程序等手段研究了稀土离子在不同基质材料中的格位取代问题及发光性质，揭示了稀土离子的发光增强机制，完成了预期目标。执行的结果主要反映在发表SCI论文24篇，授权专利1项。成果发表的杂志包括Angew. Chem. Int. Ed.、Adv, Funct. Mater.、Small、ACS Appl. Mater. Inter.、Adv. Opt. Mater.、Chem. Eng. J.、J. Mater. Chem. A和Nano Res等。在本项目基金支持下培养了24名硕士生和2名博士生，多次参加了国内外学术会议。具体研究内容如下：（1）制备了具有上下转换双功能发光性质的金属有机骨架材料（Ln-MOF），并应用于白光LEDs。（2）制备了一系列稀土纳米发光材料，包括MOF-Ln（Ln = Eu、Gd和Tb）、CQDs-N:Eu3+@MOF-Gd:Eu3+/Tb3+、CQDs:N/Eu3+、NaGdF4:Tb3+/Eu3+、NaGdF4:Tb3+/Eu3+@C:N/Eu3+、Y2O3/Y2O2S:Yb3+ ,Er3+和NaLn(MoO4)2 @In(OH)3 (Ln=Eu, Tb, Eu/Tb)等发光材料，实现了荧光增强。（3）构筑了双模发光的NaYF4:Ln3+@MOF-Y纳米复合材料，利用NaYF4:Tm3+/Yb3+和MOF-Y:Eu3+的协同效应进行生物标记和药物递送。（4）我们对稀土发光材料在白光LEDs领域的应用做了大量的探索工作。（5）在SCN-掺杂CsPbBr3的基础上还进行了MOF的复合。通过稳定性测试表明，MOF的复合进一步提高了材料的稳定性。并将材料应用于白光LEDs。（6）合成了一系列稀土复合材料，并应用于染料敏化太阳能电池光阳极，提高了电池对光的吸收能力。（7）研究了稀土纳米复合材料在光催化领域的应用（包括g-C3N4/Zn2GeO4:1%Er3+、BP:La/InVO4:La和稀土离子掺杂的硫化物/g-C3N4复合材料等）。