源自石榴籽的高发光荧光碳量子点的合成及应用研究

发布时间：2019-06-09 20:16

【摘要】：荧光碳量子点自从2004年被首次发现以来,就以细胞毒性低、耐光漂白、发射可调谐、生物相容性好以及稳定性高等优点受到了人们的广泛关注。目前,已经报道有各种各样的合成方法和碳源用于碳量子点的制备,并且碳量子点已经应用于生物成像、生物传感、光催化、光电设备等领域。但是合成高发光性能和具有表面功能化的碳量子点,并将其作为荧光探针用于生物和环境分析仍然是科研工作者面对的挑战。本论文以天然产物石榴籽为碳源,分别以乙二胺、氨基酸和核黄素为钝化剂,制备出了4种发光性能各异的碳量子点,并将其作为荧光探针分别应用于多巴胺、谷胱甘肽、对硫磷和汞离子含量的高灵敏检测。主要研究工作概括如下:以石榴籽为碳源,乙二胺为钝化剂,通过微波法一步合成了荧光碳量子点。在紫外灯照射下碳量子点发出蓝色荧光,并且对溶液的酸碱性具有良好的感应。所合成的碳量子点主要通过静电作用与多巴胺发生相互作用使碳量子点的荧光猝灭。据此建立了一种以碳量子点作为荧光探针高灵敏、高选择性检测多巴胺含量的新方法,多巴胺的线性检测范围为0.1-8μg/mL,检出限为31 ng/mL。该方法已经应用于血清和尿样中多巴胺含量的检测,样品的回收率在98.0~103.5%之间,相对标准偏差均在3.1%以内。除此之外,所合成的碳量子点还可以用于斑马鱼成像,显示出良好的生物相容性。利用石榴籽为碳源,乙二胺作为表面钝化剂,采用水热法合成荧光碳量子点。所合成的碳量子点具有蓝色荧光,量子产率为23.80%。此外,汞离子能够与碳量子点表面的-OH和-COOH配位键合,激发态的碳量子点将电子转移给了汞离子空的d轨道,造成碳量子点荧光猝灭,而谷胱甘肽能通过形成Hg-S键和汞离子选择性地键合,使得复合物解离,体系的荧光在一定程度上得到恢复。据此提出了一种荧光“关-开”型高灵敏检测谷胱甘肽的方法。当谷胱甘肽的浓度在0.1-6μM的范围内时,与体系的荧光增强值之间呈现良好的线性关系,检出限为32 nM。该方法可以应用于生物样品中谷胱甘肽的检测。以石榴籽、色氨酸和天冬氨酸为原料,利用水热法制备了荧光碳量子点。该碳量子点在紫外光下发出蓝色荧光,量子产率达到35.78%。有机磷农药对硫磷与碳量子点发生相互作用,减少了碳量子点表面的缺陷,不利于碳量子点导带中的激发态电子(e-)和价带中的空穴(h+)的非辐射复合,导致碳量子点荧光增强。从而建立了一种荧光增强型检测对硫磷的新方法。对硫磷的线性范围为0.01-1.1μM,检出限为3.7 nM。将该方法应用到环境水样中对硫磷含量的检测,样品的回收率在98.0-102.7%之间,相对标准偏差均在3.2%之内。将石榴籽和核黄素通过水热法得到了氮掺杂的荧光碳量子点。此碳量子点的量子产率高达38.83%,在紫外灯下发出黄绿色荧光。此外,汞离子能够有效地猝灭碳量子点的荧光,据此建立了荧光探针法高灵敏检测汞离子的方法。该方法检测汞离子的线性范围是0.05-7μM,检出限29 nM,并且可以应用到河水、湖水和自来水中汞离子含量的检测。荧光猝灭机理研究表明,汞离子对碳量子点的荧光猝灭为静态和动态的联合猝灭。
[Abstract]:Since the first discovery in 2004, the fluorescent carbon quantum dot has been widely concerned by the advantages of low cytotoxicity, light bleaching, tunable emission, good biocompatibility and high stability. At present, various synthesis methods and carbon sources have been reported for the preparation of carbon quantum dots, and the carbon quantum dots have been applied in the fields of biological imaging, biological sensing, photocatalysis, photoelectric equipment and the like. However, that synthesis of high light-emitting performance and surface-functionalized carbon quantum dots and the use of them as a fluorescent probe for biological and environmental analysis are still a challenge for researchers. The carbon quantum dots with different luminescent properties were prepared by using the natural product of the pomegranate seeds as the carbon source, ethylenediamine, amino acid and riboflavin, respectively, and the carbon quantum dots with different light-emitting properties were prepared and used as the fluorescent probes respectively in the dopamine and the glutathione. And the high-sensitivity detection of the content of the parathion and the mercury ions. The main research work is as follows: the pomegranate seed is used as a carbon source, and the ethylenediamine is a passivating agent, and the fluorescent carbon quantum dot is synthesized in one step by the microwave method. The blue fluorescence is emitted at the carbon quantum point under the irradiation of the ultraviolet lamp, and the acid alkali of the solution is well induced. The synthesized carbon quantum dots are mainly excited by the interaction of the electrostatic action with the dopamine to cause the fluorescence of the carbon quantum dots to be quenched. A new method for high-sensitivity and high-selectivity detection of dopamine content with carbon quantum dots as a fluorescent probe was established. The linear detection range of dopamine was 0.1-8 & mu; g/ mL, and the detection limit was 31 ng/ mL. The method has been applied to the detection of the content of dopamine in the serum and urine sample, the recovery of the sample is between 98.0 and 103.5%, and the relative standard deviation is within 3.1%. In addition, the synthesized carbon quantum dots can also be used for zebra fish imaging to show good biocompatibility. By using the pomegranate seeds as the carbon source and the ethylenediamine as the surface deactivator, the fluorescent carbon quantum dots are synthesized by a hydrothermal method. The synthesized carbon quantum dot has blue fluorescence and the quantum yield is 23.80%. in addition, that mercury ion can be combine with the-OH and-COOH on the surface of the carbon quantum dot, the carbon quantum point of the excited state is transferred to the d-orbit of the mercury ion air to cause the fluorescence of the carbon quantum dot to be quenched, and the glutathione can be selectively bonded through the formation of the Hg-S bond and the mercury ion, So that the complex is dissociated and the fluorescence of the system is recovered to a certain extent. The invention provides a method for high-sensitivity detection of glutathione in a fluorescent "Off-On" type. When the concentration of glutathione is in the range of 0.1 to 6. m u.M, a good linear relationship is exhibited between the fluorescence enhancement values of the system, and the detection limit is 32 nM. The method can be applied to the detection of glutathione in biological samples. The fluorescent carbon quantum dots were prepared by hydrothermal method using pomegranate seeds, tryptophan and aspartic acid as raw materials. The carbon quantum dots emit blue fluorescence under the ultraviolet light, and the quantum yield reaches 35.78%. The interaction between the phoxim and the carbon quantum dot by the organophosphorus pesticide reduces the defects of the surface of the carbon quantum dots, and is not beneficial to the non-radiative recombination of the excited state electrons (e-) in the conduction band of the carbon quantum dots and the holes (h +) in the valence band, leading to the fluorescence enhancement of the carbon quantum dots. And a new method for detecting the parathion by fluorescence enhanced detection is established. The linear range of parathion was 0.01-1.1. m u.M and the detection limit was 3.7 nM. The method is applied to the detection of the content of parathion in the environment water sample, the recovery rate of the sample is between 98.0 and 102.7%, and the relative standard deviation is within 3.2%. And a nitrogen-doped fluorescent carbon quantum dot is obtained by a hydrothermal method by using the pomegranate seeds and the riboflavin. The quantum yield of the carbon quantum dot is as high as 38.83%, and the yellow-green fluorescence is emitted under the ultraviolet lamp. In addition, the fluorescence of the carbon quantum dots can be effectively quenched by the mercury ions, and a method for high-sensitivity detection of the mercury ions by the fluorescence probe method is established. The method detects that the linear range of the mercury ions is 0.05-7. m u.M, the detection limit is 29 nM, and can be applied to the detection of the mercury ion content in the river water, the lake water and the tap water. The study of the fluorescence quenching mechanism shows that the fluorescence quenching of the carbon quantum dots by the mercury ions is a static and dynamic joint quenching.
【学位授予单位】：河南师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.3

【参考文献】