碳化硅量子点制备及其活体细胞荧光标记与动态示踪

发布时间：2018-04-01 20:07

本文选题：碳化硅量子点　切入点：腐蚀法制备　出处：《山东农业大学》2015年硕士论文

【摘要】：量子点材料由于具有独特的光学性能在荧光标记、成像及动态示踪方面备受关注,成为国内外纳米生物技术领域的研究热点。日前,随着对镉系量子点(如CdSe、CdTe、CdS等)研究的不断深入,其生物学应用过程中的细胞毒性问题也日趋显现,开发低毒甚至无毒的非Cd系量子点已成为业界共识,近年来,碳化硅量子点由于具有优良的光学特性及生物相容性成为最具有发展前景的新型纳米生物材料。基于此,本文开发出一种粒子尺寸及表面物化特性可调控的碳化硅量子点制备新工艺,探究了材料成型过程中微观形貌的演变过程、各工艺参数对其光学性能的影响、量子点表面修饰对其特征发射光谱的影响、SiC量子点活体细胞引入形式及其相互作用、荧光标记的活体细胞稳定性及长时程示踪等内容,获得如下结果：首先,采用化学腐蚀法,一步法制备出表面具有亲有机物基团的碳化硅量子点水相溶液,具体过程为：采用自蔓延燃烧合成的均质β-SiC粉体材料,通过调整腐蚀剂组分及相对含量,实现SiC颗粒的快速腐蚀,经降酸处理后烘干,机械研磨结合超声波空化破碎处理,最后在超重力场中层析剪裁,获得SiC量子点水相溶液。对其成型过程中微观组织形貌演变规律进行研究,结果表明,由于自蔓延燃烧具有反应迅速、冷却速度快而易形成非平衡结晶条件的特点,使得SiC颗粒表面形成较多缺陷(如晶格畸变等),腐蚀激活能较低,因此无需通电,SiC颗粒便极易在混合腐蚀剂内被腐蚀为多孔镂空结构,这对量子点尺寸调控至关重要。其次,通过调整腐蚀剂组分及其配比,可以实现SiC量子点表面亲有机物基团的有效调控,如当V(HF):V(HNO3):V(H2SO4)=6:1:1时,既能保证巯基的耦合稳定性又能保证其较大的光致发光强度。对量子点光学特性的研究结果表明,当激发光波长为340 nm时,其光致发光波长为450 nm,强度最大,斯托克斯位移可达110 nm,随着激发光波长增加,发射光将发生红移。同时,发射光波长与量子点尺寸密切相关,相同激发光波长下,随着直径减小,发射光会发生蓝移。最后,通过内吞法,实现了出芽短梗霉、串珠镰刀菌活体细胞SiC量子点稳定荧光标记与长时程成像示踪；研究了根皮苷对串珠镰刀菌生长过程的影响,对该菌侵染苹果植株根系过程进行动态示踪,结果表明,根皮苷可促进串珠镰刀菌的分裂生长过程,串珠镰刀菌侵染植株根部时,外表皮细胞并不存在特殊易感染部位。
[Abstract]:Quantum dot materials with unique optical properties in fluorescent imaging and dynamic tracing concern, become a hot research topic at home and abroad in the field of nano biotechnology. The day before, with the quantum of cadmium point (such as CdSe, CdTe, CdS etc.) the deepening of the study, the cytotoxicity of the biological problems in the application process is more, the development of low toxic or non-toxic and non Cd quantum dots has become the industry consensus, in recent years, SiC quantum dots as provided with optical properties and biological compatibility of excellent new nano biomaterials become most promising. Based on this, this paper developed a kind of particle size and surface physicochemical properties can be controlled the new process of preparing SiC quantum dots system, explores the evolution of microstructure of material forming process, effects of various parameters on the optical properties of the modified surface emitting quantum dot on its characteristics The influence of spectra of SiC quantum dots and their interactions in living cells form into living cells, stability and long fluorescence process tracing, the results obtained are as follows: firstly, using chemical etching method, a step surface was prepared with SiC QDs organophilically group phase solution, the specific process for using homogeneous beta -SiC powder materials synthesized by combustion, by adjusting the etchant composition and relative content, to achieve rapid corrosion of SiC particles, the reduction of acid treatment after drying, mechanical lapping with ultrasonic cavitation crushing, the super gravity field was cut, SiC quantum dots on the microstructure of the solution phase. In the forming process of morphology evolution was studied. The results showed that the self propagating combustion has the rapid reaction characteristics of non equilibrium crystallization condition of the formation of the cooling speed quickly and easily, so that the surface of SiC particles The formation of more defects (such as lattice distortion, etc.) the corrosion activation energy is low, so no electricity, SiC particles will easily be mixed in caustic corrosion of porous hollow structure, the quantum dot size regulation is vital. Secondly, by adjusting the etchant compositions can achieve effective control of surface SiC quantum dots organophilically groups, such as V (HF): V (HNO3): V (H2SO4) =6:1:1, which can guarantee the stability of coupled thiol can ensure that the photoluminescence intensity of the larger light. Study on optical properties of quantum dots. The results show that when the excitation wavelength is 340 nm. The photoluminescence wavelength is 450 nm, the maximum strength, Stokes displacement can reach 110 nm with increasing excitation wavelength, emission light will be shifted. At the same time, emission wavelength and the size of quantum dots is closely related to the same excitation wavelength, with the diameter decrease, emitting light blue shifts. After the method realized by endocytosis, Aureobasidium pullulans, Fusarium moniliforme living cells stabilized SiC QDs fluorescence labeling and long time imaging tracer; effects of phlorizin on growth of Fusarium moniliforme, dynamic tracing, the infection of Apple root process results show that phloridzin can promote the growth process of Fusarium moniliforme split, Fusarium moniliforme infection root, skin cells do not have special infection location.

【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：Q2-33;O471.1

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