新型荧光量子点的制备及生物传感器的构建

发布时间：2018-08-28 15:19

【摘要】：荧光量子点,是一种被称之为准零维的纳米材料,量子限域效应和边缘效应赋予其独特的光学性质。荧光量子点拥有良好的光稳定性,激发光谱宽且连续分布,与其相对的发射光谱窄而对称,荧光寿命长。近年来,荧光量子点已经在化学传感、成像等研究领域得到了广泛应用。其中,类石墨烯量子点,如:二硫化钨、黑磷及有机聚合物量子点,如:聚多巴胺量子点由于其优异的光学性能,在生物或化学传感等方面具有重要的研究价值。本硕士论文聚焦于新型二硫化钨、黑磷及聚多巴胺量子点的制备并基于其荧光性能构建了多种新型传感体系,成功实现了对硫辛酸、金属铜离子及乙酰胆碱酯酶活性的检测,具体内容如下:第一章绪论主要介绍了类石墨烯量子点及聚合物点的特点,研究现状以及应用;重点讨论了基于新型量子点构建荧光探针及其应用于化学、生命领域中重要分子检测。最后,对本硕士论文工作进行概述并阐述了研究工作的意义。第二章水溶性二硫化钨量子点的制备及硫辛酸荧光传感体系的构建我们通过超声剥离与水热法结合,利用表面活性剂CTAB成功创建了一种简单、环保合成水溶性二硫化钨量子点(WS2QDs)的新方法。所得量子点显示出优良的特性,包括尺寸分布窄、水溶性好、荧光稳定等。实验表明,此WS2QDs的荧光强度会被Fe3+通过光电子转移作用所猝灭,并且对于Fe3+的检测线性范围较宽,这表明WS2QDs可以用于Fe3+的检测。在硫辛酸(LA)的存在下,由于Fe3+与LA上的羧基的络合作用强于Fe3+与WS2 QDs的作用,因此荧光强度会回升。基于该原理,我们成功构建了检测LA的新方法,其检测线性范围为1～10 μmol/L,检测下限为0.59 μmol/L。第三章黑磷量子点的制备及免标记乙酰胆碱酶活性评估平台构建我们基于黑磷量子点(BPQDs)和2-硝基-5-硫代苯甲酸(TNB)之间产生的荧光内滤效应,建立了一种快速、灵敏、无标记的荧光检测平台,用于巯基化合物的检测;我们基于巯基检测平台,进一步实现乙酰胆碱酯酶(AChE)活性的评估,并考察了酶抑制剂溴化新斯的明和敌百虫对乙酰胆碱酯酶活性的抑制作用。实验结果表明:测得敌百虫的IC50值为1.95 μmol/L,新斯的明的IC50为18.1 nmol/L。第四章聚多巴胺点的制备及金属铜离子荧光检测体系构建神经传导物质多巴胺在碱性条件下会快速被氧化并自聚,生成聚多巴胺。基于此特性,我们发展了一种在温和条件下,利用Cu~(2+)的氧化性及Cu~(2+)/H2O2反应产生活性氧,协同氧化多巴胺自聚生成荧光聚多巴胺点的新方法。我们探索了不同金属离子对聚多巴胺点合成速率及其荧光强度影响,研究发现Cu~(2+)对聚多巴胺纳米点的合成有着极高的选择性与灵敏度。基于该原理,利用生成聚多巴胺纳米点的自身荧光,我们构建了检测Cu~(2+)的新方法,其线性范围为0.05-3 μmol/L,检测限为4.8 nM。
[Abstract]:Fluorescent quantum dots (QDs) are called quasi-zero dimensional nanomaterials, which are endowed with unique optical properties by quantum limiting effect and edge effect. The fluorescence quantum dots have good optical stability, wide excitation spectrum and continuous distribution. The emission spectrum is narrow and symmetrical, and the fluorescence lifetime is long. In recent years, fluorescent quantum dots have been widely used in chemical sensing, imaging and other fields. Among them, graphene like quantum dots, such as tungsten disulfide, black phosphorus and organic polymer quantum dots, such as polydopamine quantum dots, have important research value in biological or chemical sensing due to their excellent optical properties. This master thesis focused on the preparation of novel tungsten disulfide, black phosphorus and polydopamine quantum dots. Based on their fluorescence properties, a variety of novel sensing systems were constructed, and the activities of lipoic acid, metal copper ions and acetylcholinesterase were successfully detected. The main contents are as follows: in the first chapter, the characteristics, research status and applications of graphene like quantum dots and polymer dots are introduced, and the fluorescent probes based on new quantum dots and their applications in chemistry are discussed. Important molecular detection in the field of life. Finally, the thesis summarizes the work of this thesis and expounds the significance of the research work. In chapter 2, the preparation of water-soluble tungsten disulfide quantum dots and the construction of fluorescence sensing system for lipoic acid we have successfully created a simple one by ultrasonic stripping and hydrothermal method, using surfactant CTAB. A new method for the synthesis of water soluble tungsten disulfide quantum dots (WS2QDs) by environmental protection. The obtained QDs show excellent properties, including narrow size distribution, good water solubility and fluorescence stability. The experimental results show that the fluorescence intensity of the WS2QDs is quenched by Fe3 through photoelectron transfer, and the linear range of Fe3 detection is wide, which indicates that WS2QDs can be used for the detection of Fe3. In the presence of lipoic acid (LA), the fluorescence intensity will pick up due to the stronger complexation between Fe3 and the carboxyl groups on LA than between Fe3 and WS2 QDs. Based on this principle, we have successfully constructed a new method for detecting LA. The detection linear range is 1 ~ 10 渭 mol/L, and the detection limit is 0.59 渭 mol/L.. Chapter 3 preparation of Black phosphorus Quantum Dots and Evaluation platform of Non-labeled acetylcholinase activity We have established a rapid and sensitive method based on the fluorescence internal filtration effect between black phosphorus quantum dots (BPQDs) and 2-nitro-5-thiobenzoic acid (TNB). An unlabeled fluorescent detection platform for the detection of sulfhydryl compounds. We further evaluate the activity of acetylcholinesterase (AChE) based on the sulfhydryl detection platform. The inhibitory effects of enzyme inhibitors neostigmine bromide and trichlorfon on the activity of acetylcholinesterase were investigated. The results showed that the IC50 of trichlorfon was 1.95 渭 mol/L, and the IC50 of neostigmine was 18.1 nmol/L.. In chapter 4, the preparation of polydopamine spots and the construction of copper ion fluorescence detection system. Dopamine, a neuroconductive substance, is rapidly oxidized and self-polymerized under alkaline conditions to produce polydopamine. Based on this property, we developed a new method to produce reactive oxygen species (Ros) from Cu~ (2) and Cu~ (2) / H _ 2O _ 2 reaction under mild conditions, and to co-oxidize dopamine to produce fluorescent polydopamine point. We investigated the effects of different metal ions on the synthesis rate and fluorescence intensity of poly (dopamine). It was found that Cu~ (2) had a high selectivity and sensitivity to the synthesis of polydopamine nanoparticles. Based on this principle, a new method for the detection of Cu~ (2) was constructed by using the self-fluorescence of polydopamine nanoparticles. The linear range of the method was 0.05-3 渭 mol/L, and the detection limit was 4.8 nM..
【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.3

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