液体石蜡体系CdSe量子点制备及果蝇成像研究

发布时间：2018-03-17 15:19

  本文选题：CdSe量子点　切入点：温度调控合成　出处：《中南大学》2012年硕士论文　论文类型：学位论文

【摘要】：研究生物分子间的相互作用以及对重大疾病的早期诊断,迫切需要在微观尺度上原位、活体、实时地获取各种生物化学信息,因此制备具有生物相容性,荧光性能强、小尺寸的荧光材料具有重要应用价值。量子点以其优异的光学特性如吸收光谱连续,发射光谱依粒子尺寸变化可调,荧光量子产率高和耐光漂白等特点在生物医学领域如生物分子的标记和检测,细胞标记/成像,活体成像,肿瘤的诊断和治疗等领域展现了广泛的应用前景。然而制备尺寸均一、荧光性能稳定,具有生物相容性的量子点已经成为其生物医学应用领域的重大挑战。本论文研究了液体石蜡体系中通过温度调控的简易制备尺寸分布均一CdSe量子点的方法。通过以液体石蜡为溶剂,油酸为表面包覆有机基团,合成CdSe量子点。研究制备过程中反应时间、反应温度和前驱体等因素对制备CdSe量子点结晶性、粒径分布和荧光发射光谱等性能的影响规律；利用电子透射显微镜(TEM),高分辨电子透射显微镜(HRTEM),选择区域衍射(SEAD), X射线衍射(XRD),荧光光谱(PL)及紫外可见吸收光谱(UV-VIS)表征制备CdSe量子点形貌量子点尺寸晶体结构及荧光紫外性能。实验表明液体石蜡体系中生长温度(T)与CdSe量子点尺寸(d)存在线性相关性d=0.0207T-0.7068,各生长温度下量子点粒径分别为：140℃为2.3nm,180℃为3nm,210℃为3.3nm,240℃为4.5nm。热力学基本原理计算液体石蜡体系中温度调控时ΔG0,促使粒径生长；当油酸比例从(OA:CdO=4:1)升至(OA:CdO=10:1)时,有机基团的过量吸附会导致样品缺陷发光的增加,从而荧光下降；而过低(OA:CdO=3:1)会使得制备Cd前驱体困难,造成大量沉淀的产生,合成温度从140℃上升至180℃,210℃或240℃时,有利于CdSe量子点结晶并提高荧光性能；利用巯基丙酸(MPA)修饰CdSe量子点后暴露果蝇,闪锌矿结构的CdSe量子点水溶液分散后尺寸分布均匀,水合动力学尺寸为30nm；利用荧光倒置显微镜观测CdSe量子点在果蝇体内分布状况,发现CdSe量子点成功进入果蝇体内且主要分布在肠道位置。
[Abstract]:In order to study the interaction between biomolecules and the early diagnosis of major diseases, there is an urgent need to obtain biochemistry information in situ, in vivo and in real time at the micro scale. Therefore, the preparation has biocompatibility and strong fluorescence performance. Small size fluorescent materials have important application value. Quantum dots have excellent optical properties such as continuous absorption spectra, and the emission spectra can be adjusted according to particle size. The characteristics of high fluorescence quantum yield and photobleaching resistance in biomedical fields such as biomolecules labeling and detection, cell labeling / imaging, in vivo imaging, The diagnosis and treatment of tumors have shown a wide range of applications. However, the size of the preparation is uniform, and the fluorescence performance is stable. Biocompatible quantum dots (QDs) have become a major challenge in biomedical applications. In this paper, a simple method of preparing uniform CdSe quantum dots with uniform size distribution by temperature control in liquid paraffin system has been studied. Using liquid paraffin as solvent, The effects of reaction time, reaction temperature and precursor on the crystallinity, particle size distribution and fluorescence emission spectra of CdSe quantum dots were studied. CdSe quantum dots were characterized by electron transmission microscope (TEM), high resolution electron transmission microscope (HRTEM), selective region diffraction (SEAD), X-ray diffraction (XRD), fluorescence spectrum (PL) and UV-VIS (UV-VIS). The experimental results show that there is a linear correlation between the growth temperature (T) and the size of CdSe quantum dots (d) in liquid paraffin system. The particle size of quantum dots at each growth temperature is 1: 140 鈩，

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