基于Mn-ZnS量子点室温磷光对生物分子的识别分析

发布时间：2018-06-07 11:36

本文选题：掺杂量子点 + 室温磷光　；参考：《山西师范大学》2017年硕士论文

【摘要】：生物分子的研究使人们从基因水平上了解某些疾病的发病机理,并且通过分子探针的设计对机体内生物分子的含量进行痕量检测,为各种疾病的发生提供一定的理论依据,同时为临床医学中使用剂量的有效控制提供一定的理论指导。纳米分子探针具备水溶性好、光化学稳定、比表面积大等特性,提高了传统生物分子探针的检测性能。而室温磷光(Room-temperature phosphorescence,RTP)量子点纳米分子探针不但具备上述优点,还可以避免生物体液背景荧光及散射光干扰,在进行生物样品检测时更精准。本研究利用室温磷光量子点的光学性质,将其以纳米探针的形式对几种重要的生物分子(DNA、细胞色素C、壳寡糖)进行检测。主要研究内容如下:(1)通过3-巯基丙酸(3-Mercaptopropionic Acid,MPA)包裹的Mn掺杂ZnS(Mn-ZnS)量子点(Quantum Dots,QDs)与亚甲基蓝(Methylene Blue,MB)之间的静电作用构建了一种纳米复合物,并将其应用于DNA的痕量检测。其检测原理为:亚甲基蓝通过静电作用与Mn-ZnS QDs结合,并通过光诱导电子转移(Photoinduced Electron Transfer,PIET)过程猝灭了Mn-ZnS QDs的RTP;随着DNA的加入,亚甲基蓝通过嵌插和静电作用与DNA结合,并且亚甲基蓝从Mn-ZnS QDs表面脱附,使得QDs的RTP恢复;据此,建立了一种基于RTP性质的DNA检测方法。该方法的检测范围为0.2-20 mg/L,方法检出限为0.113 mg/L。由于该DNA检测方法是基于QDs的RTP,避免了来自生物体液的背景荧光及散射光的干扰,且无需复杂的样品前处理过程,因此该方法适合于生物体液中DNA的痕量检测。(2)利用水相合成法制备了MPA包裹的Mn-ZnS QDs,基于该QDs的RTP性质,构建了一种灵敏、快速检测细胞色素C(Cytochrome C,Cyt C)含量的新方法。该检测方法利用QDs与Cyt C之间发生电子传递过程,使得QDs的RTP猝灭,从而对Cyt C的含量进行检测。在pH=7.4的磷酸缓冲液中,Cyt C通过电子传递可以猝灭Mn-ZnS QDs在590 nm处的RTP,且在一定的范围内Cyt C浓度与RTP猝灭强度(P0/P)呈现良好的线性关系,线性范围为0.1-10μM和10-40μM,相关系数为0.990和0.991,方法检出限为0.062μM,该方法适用于Cyt C的痕量检测。(3)通过MPA包裹的Mn-ZnS QDs与壳寡糖(chitosan oligosaccharide,COS)之间的静电作用,构建了一种精准、高效检测壳寡糖含量的新方法。该检测方法利用QDs与壳寡糖之间的相互作用,使得QDs的RTP增强,从而对壳寡糖的含量进行检测。在pH=7.4的磷酸缓冲液中,壳寡糖可以加强Mn-ZnS QDs在590nm处的RTP,且在一定的范围内壳寡糖浓度与RTP增强强度(P/P0)呈现良好的线性关系,线性范围为0.06-10μg/mL,相关系数为0.988,方法检出限为0.028μg/mL,该方法适用于壳寡糖的痕量检测。总之,本文利用QDs的RTP性质,通过构建纳米探针对生物分子DNA、细胞色素C、壳寡糖的含量进行检测,为分子生物学及各种疾病发生的研究提供了一定的理论依据。
[Abstract]:The study of biomolecules enables people to understand the pathogenesis of some diseases from the gene level, and to detect the content of biomolecules in the organism by the design of molecular probes, which provides a certain theoretical basis for the occurrence of various diseases. At the same time, it provides some theoretical guidance for effective control of dosage in clinical medicine. Nano-molecular probes have the characteristics of good water solubility, photochemical stability and large specific surface area, which improve the detection performance of traditional biomolecular probes. The room temperature phosphorescence (RTP) quantum dot nano-molecular probe not only has the advantages, but also avoids the interference of background fluorescence and scattering light, and is more accurate in the detection of biological samples. In this study, the optical properties of room temperature phosphorescent quantum dots (RQDs) were used to detect the DNA, cytochrome C and oligosaccharide of several important biomolecules in the form of nano-probe. The main contents of this study are as follows: (1) A nanocomposite was constructed by electrostatic interaction between Mn-doped ZnSn-ZnSn-ZnSn-ZnDs) and methylene blue methylene (MBB), which was encapsulated by 3-Mercaptopropionic Acid-MPA-encapsulated with 3-mercaptopropionic MPA. The nanocomposites were used for the determination of trace amounts of DNA. The detection principles are as follows: methylene blue binds to Mn-ZnS QDs by electrostatic interaction and quenches Mn-ZnS QDs through photoinduced Electron transfer via photoinduced electron transfer. With the addition of DNA, methylene blue binds to DNA through intercalation and electrostatic interaction. The methylene blue was desorbed from the surface of Mn-ZnS QDs to restore the RTP of QDs, and a DNA detection method based on RTP property was established. The detection range of the method is 0.2-20 mg / L, and the detection limit is 0.113 mg / L. Because the DNA detection method is based on QDs, it avoids the interference of background fluorescence and scattering light from biological body fluid, and does not need complicated sample pretreatment process. Therefore, this method is suitable for the trace detection of DNA in biological fluid. (2) based on the RTP properties of MPA, a new sensitive and rapid method for detecting the content of cytochrome C(Cytochrome Cy C was constructed by using the aqueous phase synthesis method to prepare Mn-ZnS QDsencapsulated with MPA. This method uses the electron transfer process between QDs and Cyt C to quench the RTP of QDs, so that the content of Cyt C is determined. In the phosphoric acid buffer of pH=7.4, Cyt C can quench the Mn-ZnS QDs at 590nm by electron transfer, and there is a good linear relationship between the concentration of Cyt C and the quenching intensity of RTP (P0 / P0) in a certain range. The linear ranges are 0.1-10 渭 M and 10-40 渭 M, the correlation coefficients are 0.990 and 0.991.The detection limit of the method is 0.062 渭 M. this method is suitable for the trace detection of Cyt C. This method is suitable for the detection of Cyt C by electrostatic interaction between Mn-ZnS QDs wrapped with MPA and chitosan oligosaccharides. A new method for the determination of chitosan oligosaccharide content. By using the interaction between QDs and oligosaccharides, the RTP of QDs was enhanced, and the content of chitosan oligosaccharide was detected. In the phosphoric acid buffer of pH=7.4, the chitosan oligosaccharide can enhance the Mn-ZnS QDs at 590nm, and the concentration of chitosan oligosaccharide has a good linear relationship with the enhancement strength of RTP in a certain range. The linear range is 0.06-10 渭 g / mL, the correlation coefficient is 0.988, and the detection limit is 0.028 渭 g / mL. This method is suitable for the trace determination of chitosan oligosaccharides. In conclusion, the content of DNA, cytochrome C and oligosaccharide in biomolecules were detected by using the RTP properties of QDs, which provided a theoretical basis for the study of molecular biology and the occurrence of various diseases.
【学位授予单位】：山西师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O471.1;R318

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