荧光生物量子点的制备及其应用研究

发布时间：2018-03-23 19:33

本文选题：水热制备法　切入点：生物量子点　出处：《南昌大学》2015年硕士论文

【摘要】：生物量子点(bio-dots)和荧光碳量子点(CQDs)是最近兴起的新颖荧光纳米材料,相对于传统的半导体量子点而言,具有非常明显的优势。除了光学性能优良,bio-dots和CQDs还具有的毒性低、环境友好、制备方法简单、成本低等优点,让它们在化学和生物传感领域有很大的应用前景。本论文利用水热方法成功制备了bio-dots和CQDs,通过对荧光量子点的表征,概述了其基本特征并深入探讨了其在分析化学领域的应用。研究的主要内容如下:(1)以富含C碱基的DNA链作原料,通过低温水热法制备了荧光bio-dots。采用透射电镜(TEM)、原子力显微镜(AFM)对bio-dots形貌进行了表征,结果表明,其粒径约为16 nm,厚度约为0.8 nm。用X-射线光电子能谱(XPS)对bio-dots成分进行了分析,结果表明,bio-dots既保留了DNA的C碱基又与DNA的成分大致相同。利用荧光光谱(FL)对bio-dots进行了光谱表征,其荧光发射波长不随激发波长的变化而改变,当激发波长从260 nm增加320 nm时,bio-dots的发射波长均为420 nm。此外,实验结果表明bio-dots的耐光漂白性强,然而pH对bio-dots的发光有较大影响。(2)基于bio-dots与Ag+的相互作用构建光致发光传感平台,用于谷胱甘肽(GSH)和谷胱甘肽还原酶(GR)活性的检测。利用bio-dots与DNA结构类似的特性,以Ag+作为桥梁与bio-dots的C碱基配位形成C-Ag+-C配合物,从而破坏bio-dots的发光中心,导致bio-dots荧光猝灭。由于Ag+与巯基的配位能力比与C碱基更强,当加入GSH时,Ag+首先与GSH结合,使bio-dots结构不被破坏,因而荧光不猝灭,据此实现GSH定量分析。此外,基于GR-催化酶促反应对GR活性和氧化型谷胱甘肽(GSSH)进行了定量分析并用于抑制剂的筛选。(3)以尿酸作为碳源,180oC水热反应8 h即可获得蓝色荧光的CQDs。铜在许多生物进程中被认为是一种重要的微量元素,广泛的参与生命的进程,人体内铜离子超标会破坏人体中的代谢平衡产生一系列的疾病,如门克斯病、威尔逊病、阿尔茨海默病和普里昂疾病等。本文利用荧光CQDs表面丰富的氮、氧基团与Cu2+发生配位作用,导致荧光猝灭,根据荧光猝灭程度对Cu2+进行了定量分析,检测Cu2+线性范围为1-15μM。
[Abstract]:Biological quantum dots (bio-dotss) and fluorescent carbon quantum dots (CQDs) are novel fluorescent nanomaterials, which have obvious advantages over traditional semiconductor quantum dots. In addition to their excellent optical properties, bio-dots and CQDs have low toxicity. Due to their advantages of environmental friendliness, simple preparation method and low cost, they have great application prospects in chemical and biological sensing fields. In this paper, bio-dots and CQDswere successfully prepared by hydrothermal method, and characterized by fluorescence quantum dots. The main contents of this study are as follows: (1) the DNA chain rich in C bases is used as raw material. Fluorescence bio-dots were prepared by hydrothermal method at low temperature. The morphology of bio-dots was characterized by TEM and AFM. The results showed that the particle size was about 16 nm and the thickness was about 0.8 nm. The composition of bio-dots was analyzed by X-ray photoelectron spectroscopy (XPS). The results show that the C base of DNA is retained and the composition of bio-dots is about the same as that of DNA. The spectra of bio-dots are characterized by fluorescence spectra. The fluorescence emission wavelength does not change with the change of excitation wavelength. When the excitation wavelength is increased from 260 nm to 320 nm, the emission wavelengths of bio-dots are 420nm. In addition, the experimental results show that the photobleaching resistance of bio-dots is strong, but pH has a great effect on the luminescence of bio-dots. It is used for the detection of glutathione glutathione (GSH) and glutathione reductase (Glutathione reductase) activity. Using the similar structure of bio-dots and DNA, Ag is used as a bridge to coordinate with C base of bio-dots to form C-Ag C complex, which destroys the luminescent center of bio-dots. The fluorescence quenching of bio-dots is caused. Because Ag has stronger coordination ability with sulfhydryl than with C base, when GSH is added, Ag binds to GSH first, so the structure of bio-dots is not destroyed, thus the fluorescence is not quenched, so the quantitative analysis of GSH is realized. Gr activity and oxidized glutathione (GSSH) were quantitatively analyzed based on GR-catalyzed enzymatic reaction and were used to screen inhibitors. The blue fluorescence CQDs. copper was obtained by hydrothermal reaction of 180oC with uric acid as carbon source for 8 h. Cheng Zhong is considered to be an important trace element. With extensive participation in the process of life, excessive copper ions in the human body can disrupt the metabolic balance in the body and produce a range of diseases, such as Menkes disease, Wilson's disease, In this paper, the rich nitrogen and oxygen groups on the surface of fluorescent CQDs were used to coordinate with Cu2, which led to fluorescence quenching. The quantitative analysis of Cu2 was carried out according to the degree of fluorescence quenching. The linear range of detection of Cu2 was 1-15 渭 M.
【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1

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