基于毛细管电泳的复杂基体中量子点与多种配体竞争交换机理的研究方法

项目名称： 基于毛细管电泳的复杂基体中量子点与多种配体竞争交换机理的研究方法

项目编号： No.21475053

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 陈宏丽

作者单位： 兰州大学

项目金额： 84万元

中文摘要： 配体交换是改善量子点(QDs)性质和功能的有效手段，也是了解生物颗粒与配体相互作用的重要途径。通过对配体交换机理的研究，可深入理解量子点与配体的作用方式，为新型量子点探针的开发和应用提供一定的理论指导。然而，目前常用的表征手段，如TEM、FT-IR、UV-Vis、荧光、液体NMR等都无法实现复杂基体如生命物体中多种配体的竞争交换研究。毛细管电泳 (CE) 具有高效、快速、经济的优点，谱峰与待测物的电荷和尺寸密切相关，是研究复杂基体中配体交换的理想方法。因此，本项目拟采用紫外和激光诱导荧光两种检测技术、结合CE多种分离模式和柱上富集手段、依据CE谱峰强度和迁移时间的变化，定量进行不同配体与不同粒径/形貌/结构的量子点的竞争交换机理和动力学研究。该方法无需提纯量子点，能真实、直观地反映复杂基体中配体交换的过程和程度，可为生物颗粒(如脂质体)与配体的结合和交换研究提供一种新的方法。

中文关键词： 配体交换机理；量子点；毛细管电泳；复杂基体

英文摘要： Ligand exchange is an important strategy not only for improving the water solubility and biological compatibility of quantum dots (QDs), but also for understanding the interaction between biological particles and ligands. The study on the ligand exchange mechanism can help us understand the QDs-ligand interaction and design novel QDs sensors for practical application. The common techniques used to study the ligand exchange mechanism include transmission electron microscopy (TEM), dynamic light scattering (DLS), atomic force microscope (AFM), infrared spectroscopy (IR), ultravoilet-visible spectroscopy (UV-Vis) and photoluminescence spectroscopy. But all these ensemble techniques stay at a mixture level without a separation process, and are incapable to straightly probe the ligand exchange mechanism. Moreovre, the additional operations to obtain the purified QDs is necessary, such as firstly precipitating from the complex solution and then redispering into another fresh solvent, which easily results in the change of the QDs surface property. Various solution nuclear magnetic resonance spectroscopy (solution NMR) can distinguish the bound and free ligands, so is a powerful tool to qualitatively and quantitatively characterize the ligand exchange on QDs surface. But NMR is only available for the simple system such as one QDs and one new ligand, but incompetent for more complex system. Capillary electrophoresis (CE) is one of the principal separation and analysis techniques with versatile advantages of high efficiency, short analysis time, low sample and reagent consumption. The development of various kinds of CE separation modes and on-column preconcentration strategies makes it a powerful tool for a wide range application. The electrophoretic peak of an analyte is closely related to its charge and size, so CE should be a perfect tool to characterize the ligand exchange mechanism on QDs surface. In the project, based on the changes in the intensity and migration time of CE peak, combining the peak identification from the cooperation of ultraviolet (UV) and laser induced fluorescence (LIF) detections, the ligand exchange mechanism on QDs surface with diffirent sizes/morpholy/structure and capping ligands after adding new ligands will be visualizedly demonstrated. Furthermore, the ligand coordination number on QDs surface and the detailed kenetic process of the ligand exchange can be quantitatively obtained. The strategy is very simplified without the need to purify QDs, therefore it can truly reflect the QDs surface property and demonstrate the process and degree of the competitive ligand exchange in complex matrix. The successful implementation of the project will provide a simple and visualized method to study the interaction and exchange mechanism between biological particles (such as liposome) and ligands (such as amino acids, protein and some drug molecule).

英文关键词： Ligand exchange mechanism;Quantum dots;Capillary electrophoresis;Complex matrix