荧光碳量子点的合成及其在分析检测中的应用

发布时间：2018-11-03 19:29

【摘要】：碳量子点由于其优良的光学性能、良好的生物相容性和低细胞毒性等优点,被广泛应用于分析检测、环境监测、生物成像、药物传递与释放、疾病的诊断和治疗等领域。为进一步扩大其应用范围,尤其是在生物医学方面的应用,必须不断改进合成方法和技术,制备出强荧光性能、高荧光量子产率、低毒性以及良好的生物相容性的碳量子点,并深入研究其发光机理,为应用提供充足的理论依据。近年来,农药及兽药残留、药品的制假售假、食品添加剂超标等问题不断涌现,严重威胁到人类的生活和身体健康。因此,针对常见药物分子和食品添加剂建立一种可靠、快速、灵敏的检测方法刻不容缓。基于以上问题,本论文主要开展了以下工作:以L-精氨酸为碳源,采用水热法一步合成了荧光碳量子点(C-dots),并对其合成条件进行了简单的考察,通过紫外吸收光谱、荧光光谱、傅立叶变换红外光谱以及X射线光电子能谱等手段对其进行了表征分析。基于多巴胺(DA)对C-dots的荧光具有明显的猝灭作用,设计了检测多巴胺的荧光探针。且当浓度在0.50-100.00μM范围内时,碳点的荧光猝灭程度与多巴胺的浓度呈良好的线性关系,相关系数R=0.9995,检出限低至93 nM。对市售盐酸多巴胺注射液和健康成人的尿样中多巴胺进行检测,得到回收率和精密度(RSD)范围分别为100.29%-104.21%和0.47%-5.42%。以栀子花为碳源,采用一步水热法制备了具有强蓝色荧光的碳量子点溶液,并利用多种表征手段对其性质进行了分析。利用甲硝唑(MNZ)能导致合成碳点发生荧光猝灭现象,且在浓度为2.50-225.00μM范围内,其荧光猝灭程度与甲硝唑的浓度呈良好的线性关系,相关系数R=0.9971,检出限为279 nM。对市售的两种品牌的甲硝唑片进行检测时,得到回收率和精密度(RSD)分别为91.32%-104.37%和0.44%-1.20%,结果令人满意。以芦荟为碳源,采用水热法一步合成了具有黄绿色荧光的碳量子点溶液。并采用多种手段对其进行了分析表征。以C-dots为荧光分子,柠檬黄(TZ)为猝灭剂,基于二者间静态猝灭的原理建立了简便、快速检测柠檬黄的荧光探针。在浓度为0.25-32.50μM范围内,荧光猝灭程度与柠檬黄浓度呈良好的线性关系,相关系数R=0.9993,检出限低至73 nM。将该方法应用于食品样品中柠檬黄的检测,得到日内和日间回收率分别为88.56%-103.74%和87.27%-106.60%,日内和日间精密度(RSD)分别为0.18%-3.90%和0.37%-5.82%。
[Abstract]:Due to its excellent optical properties, good biocompatibility and low cytotoxicity, carbon quantum dots are widely used in analytical detection, environmental monitoring, biological imaging, drug delivery and release, disease diagnosis and treatment. In order to further expand its application, especially in biomedical applications, it is necessary to continuously improve the synthetic methods and techniques to prepare carbon quantum dots with strong fluorescence properties, high fluorescence quantum yield, low toxicity and good biocompatibility. The luminescence mechanism is studied in depth to provide sufficient theoretical basis for application. In recent years, pesticide and veterinary drug residues, drug counterfeiting and sale, food additives over the standard and other problems continue to emerge, seriously threatening human life and health. Therefore, it is urgent to establish a reliable, rapid and sensitive detection method for common drug molecules and food additives. Based on the above problems, the main work of this thesis is as follows: fluorescent carbon quantum dots (C-dots) were synthesized by hydrothermal method using L-arginine as carbon source. Fluorescence spectra, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy were used to characterize them. Based on the obvious quenching effect of dopamine (DA) on the fluorescence of C-dots, a fluorescence probe for the detection of dopamine was designed. When the concentration was in the range of 0.50-100.00 渭 M, the fluorescence quenching degree of carbon point showed a good linear relationship with the concentration of dopamine. The correlation coefficient was 0.9995, and the detection limit was as low as 93 nM.. The recovery and precision (RSD) range of dopamine hydrochloride injection and healthy adult urine samples were 100.29-104.21% and 0.47-5.42%, respectively. Carbon quantum dots with strong blue fluorescence were prepared by one-step hydrothermal method with gardenia as carbon source and their properties were analyzed by various characterization methods. Using metronidazole (MNZ) can lead to fluorescence quenching of synthetic carbon point, and the fluorescence quenching degree of metronidazole is linear with the concentration of metronidazole in the range of 2.50-225.00 渭 M. the correlation coefficient is 0.9971, and the fluorescence quenching degree of metronidazole is linear to that of metronidazole in the range of 2.50-225.00 渭 M. Detection limit is 279 nM. The recovery and precision of metronidazole tablets were 91.32 -104.37% and 0.44 -1.20%, respectively. The results were satisfactory. The solution of carbon quantum dots with yellowish green fluorescence was synthesized by hydrothermal method using aloe vera as carbon source. It was characterized by various methods. Using C-dots as fluorescence molecule and lemon yellow (TZ) as quenching agent, a simple and rapid fluorescence probe for the detection of lemon yellow was established based on the principle of static quenching between the two. In the concentration range of 0.25-32.50 渭 M, the fluorescence quenching degree showed a good linear relationship with the concentration of lemon yellow. The correlation coefficient was 0.9993, and the detection limit was as low as 73 nM.. The method was applied to the determination of lemon yellow in food samples. The recoveries were 88.56% -103.74% and 87.27% -106.60%, respectively. The intra-day and inter-day precision (RSD) were 0.18- 3.90% and 0.37-5.82%, respectively.
【学位授予单位】：西华师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O657.3

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