荧光碳纳米材料的合成及在光敏传感与细胞成像中的应用研究

发布时间：2019-05-05 06:39

【摘要】：碳类量子点(Carbon-based Quantum Dots,CQDs)作为一种新型的荧光碳纳米材料,因其具备良好的光学特性、电学性质和生物性质,能够很好的应用于光电设备、传感器、生物成像及生化分析领域。事实上,在生物领域,常用传统的有机染料作为标记试剂对细胞和生物分子进行染色或修饰标记进行细胞和分子鉴别与测量；而在光电设备及传感器方面也是半导体量子点研究的更多并且更透彻。然而,这类传统有机染料往往因为荧光寿命短、生物相容性差、易光分解且分解产物通常有毒有害、难以进行多色同时标记等不足限制了其在生化分析方面的应用；而半导体量子点往往含有重金属元素,难免阻碍了它在传感器和光电设备方面的发展。与传统有机染料和半导体量子点比较而言,CQDs作为一种新型荧光标记试剂,避免了以上种种不足并且以其良好的生物相容性、高效且稳定的荧光强度、窄且对称的发射峰等优势引起了新的研究热潮。本文主要开展了基于热解不同前驱体合成CQDs并研究其光学性质及应用的工作。主要内容如下：(1)利用链霉素作为前驱体通过水热合成方法制备得到一种氮掺杂CQDs得到的CQDs化学性质稳定、尺寸均一、细胞毒性低,并且具有较好的细胞成像能力。(2)通过一步法固相热处理谷胱甘肽制备得到氮硫共掺杂CQDs。此方法简单、绿色,合成得到的CQDs具备尺寸均一、荧光性能好且稳定等优点。以此CQDs为荧光探针,可以实现Hg2+的高灵敏性和高选择性检测。(3)利用过硫酸铵、葡萄糖和乙二胺作为前驱体通过热处理的方法合成得到了氮硫共掺杂CQDs。相比于空白的CQDs,这种CQDs不仅显示了很好的荧光特性以及较高的量子产率,同时具有规则的形貌和优良的化学稳定性。以此氮硫共掺杂CQDs作为探针,可以实现甲氨蝶呤的高灵敏性和高选择性检测,并且可以对实际样品中的甲氨蝶呤进行检测。(4)通过热解柠檬酸和硫脲混合物制备得到一种氧硫共掺杂的石墨相氮化CQDs。这种氮化CQDs显示了很好的荧光性能,其中量子产率为14.5%。此外,以此CQDs为荧光探针可以实现Hg2+的高灵敏性和高选择性检测,且具备较好的细胞成像能力。
[Abstract]:Carbon quantum dots (Carbon-based Quantum Dots,CQDs), as a new type of fluorescent carbon nanomaterials, have good optical, electrical and biological properties, and can be used in photoelectric devices and sensors. Bioimaging and biochemical analysis. In fact, in the field of biology, traditional organic dyes are often used as labeling reagents to stain or modify cells and biomolecules for cell and molecular identification and measurement. And in the photoelectric device and the sensor aspect also is the semiconductor quantum dot research more and more thorough. However, due to their short fluorescence life, poor biocompatibility, easy photolysis and toxic and harmful decomposition products, it is difficult to carry out multi-color simultaneous labeling, which limits the application in biochemical analysis of this kind of traditional organic dyestuffs, such as short fluorescence lifetime, poor biocompatibility, easy to decompose, and toxic and harmful products. Semiconductor quantum dots often contain heavy metal elements, which inevitably hinder the development of sensors and optoelectronic devices. Compared with traditional organic dyes and semiconductor quantum dots, CQDs, as a new fluorescent labeling reagent, avoids all these shortcomings and has good biocompatibility, high efficiency and stable fluorescence intensity. Narrow and symmetrical emission peaks lead to a new research boom. In this paper, the synthesis of CQDs based on pyrolysis precursors and its optical properties and applications have been studied. The main contents are as follows: (1) using streptomycin as precursor to prepare a nitrogen-doped CQDs by hydrothermal synthesis, the chemical properties of a nitrogen-doped CQDs are stable, the size is uniform, and the cytotoxicity is low. (2) nitrogen-sulfur co-doped CQDs. was prepared by one-step solid-state heat treatment of glutathione. This method is simple and green, and the synthesized CQDs has the advantages of uniform size, good fluorescence performance and stability. High sensitivity and selectivity of Hg2 can be achieved by using CQDs as fluorescence probe. (3) nitrogen-sulfur co-doped CQDs. was synthesized by heat treatment using ammonium persulfate, glucose and ethylenediamine as precursors. Compared with blank CQDs, this CQDs not only shows good fluorescence properties and high quantum yield, but also has regular morphology and excellent chemical stability. High sensitivity and selectivity of methotrexate can be achieved by using this nitrogen-sulfur co-doped CQDs as probe. Methotrexate can be detected in real samples. (4) an oxygen-sulfur co-doped graphite phase CQDs. was prepared by pyrolysis of citric acid and thiourea mixture. This nitride CQDs shows good fluorescence properties, in which the quantum yield is 14.5%. In addition, CQDs can be used as a fluorescent probe to detect Hg2 with high sensitivity and selectivity, and it has good imaging ability.
【学位授予单位】：浙江师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O657.3;TB383.1

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