近红外发光Ⅰ-Ⅳ族量子点的水相合成及其在分析中的应用

发布时间：2018-04-14 02:05

本文选题：近红外量子点 + 低温水相合成　；参考：《桂林理工大学》2017年硕士论文

【摘要】：近红外量子点以其不同于传统荧光染料的优异的光学性质,使其在太阳能电池、化学分析、药物残留检测、光催化、LED等领域等方面得到广泛的应用。水相合成法具有操作简单、生物相容性好等优点。本文主要在常温下利用水相法一步合成了低毒的近红外荧光量子点,并在此基础上重点探究了Ag_2S、Ag_2Se量子点作为荧光探针在分析领域和生物领域(金属离子和抗生素检测)方面的具体应用。论文主要内容如下:(1)采用常温水相制备了近红外发光的Ag_2S、Ag_2Se量子点(QDs)。同时研究了原料的摩尔比、pH值、表面活性剂、温度、反应时间等因素对Ag_2S、Ag_2Se量子点荧光性质以及光学稳定性的影响,并利用X射线粉末衍射、透射电镜、荧光光谱仪和紫外可见吸收光谱等仪器对量子点的形貌,结构,价态等进行了表征。研究表明:当表面修饰剂为N-乙酰基-L-半胱氨酸,溶液体系pH值为4.2-4.4时,N-乙酰基-L-半胱氨酸/Ag~+的摩尔比为6/5,Ag~+/X(X=S、Se)的摩尔比分别为5/1、20/3时,制备的水溶性近红外发光的NAC-Ag_2S/Ag_2Se QDs荧光性能最好。在研究Ag_2S、Ag_2Se QDs的稳定性的过程中发现,在常温保存的条件下Ag_2S、Ag_2Se QD的荧光强度在80天内基本保持不变;Ag_2S、Ag_2SeQDs的荧光强度在氙灯照射480min后仍基本保持不变。(2)将Ag_2S、Ag_2Se作为荧光探针,基于荧光猝灭机理分别用来检测溶液中的Cu2+、Hg~(2+)、Ag~+浓度。研究表明,Ag_2S、Ag_2SeQDs的荧光特征峰强度变化与三者金属离子浓度之间呈现良好的线性关系。(3)利用Ag_2S、Ag_2Se QDs作为荧光探针定量检测硫酸链霉素发现,硫酸链霉素能在一定程度上增强Ag_2S、Ag_2Se QDs的荧光强度,Ag_2S QDs的相对荧光增强程度I与2.5×10~(-7)~17.5×10~(-7)mol/L范围内的硫酸链霉素呈现出良好的线性关系,拟合后线性方程:I=0.009+1.032C,线性相关系数R=0.9971,Ag_2S QDs对硫酸链霉素的最低检测限为1.99×10~(-7)mol/L。Ag_2Se量子点与硫酸链霉素在5×10~(-7)~15×10~(-7)mol/L范围内呈线性关系,拟合后线性方程:I=0.791+0.064C,线性相关系数R=0.9979,Ag_2Se QDs对硫酸链霉素的最低检测限为2.3×10~(-7)mol/L。
[Abstract]:Near-infrared quantum dots (NIR QDs) have been widely used in solar cells, chemical analysis, drug residue detection, photocatalytic LED and other fields due to their excellent optical properties, which are different from traditional fluorescent dyes.Water phase synthesis has the advantages of simple operation and good biocompatibility.In this paper, low toxic near infrared fluorescence quantum dots were synthesized by using aqueous phase method at room temperature.On the basis of this, the specific applications of AgS _ 2S _ e quantum dots as fluorescent probes in the field of analysis and biology (metal ions and antibiotic detection) are emphatically explored.The main contents of this paper are as follows: (1) the near infrared luminescent Ag _ 2S _ I _ (Ag _ 2Se) quantum dots QDsN have been prepared by using water phase at room temperature.At the same time, the effects of the molar ratio of raw materials, such as pH value, surfactant, temperature, reaction time and so on, on the fluorescence properties and optical stability of Ag2S- Ag-2Se quantum dots were studied, and X-ray powder diffraction and transmission electron microscopy were used to study the fluorescence properties and optical stability of Ag2Se quantum dots.The morphology, structure and valence state of quantum dots were characterized by fluorescence spectrometer and UV-Vis absorption spectroscopy.The results show that when the surface modifier is N-acetyl-L-cysteine and the pH value of the solution is 4.2-4.4, the molar ratio of N-acetyl-L-cysteine to cysteine / Ag- is 6 / 5 / 5G ~ / X ~ (X) -X ~ (-) S _ (See) = 5 / 1 / 20 / 3, respectively, when the molar ratio of N-acetyl-L-cysteine to cysteine is 6 / 5 / 5.The water soluble near infrared luminescent NAC-Ag_2S/Ag_2Se QDs has the best fluorescence properties.In the course of studying the stability of Ag2SX AgSe QDs, it was found that the fluorescence intensity of Ag2Sn Ag2SE QD remained basically the same for 80 days under normal temperature preservation. The fluorescence intensity of Ag2SU Ag2SeQDs remained basically unchanged after Xenon lamp irradiating 480min.) Ag2Sv / Ag2Se was used as fluorescence probe.The fluorescence quenching mechanism was used to detect the concentration of Cu2 in solution.The results show that there is a good linear relationship between the peak intensity of fluorescence characteristic and the concentration of metal ions in Ag2SX / Ag2SeQDs.) the quantitative detection of streptomycin sulfate by Ag2SX Ag2Se QDs as a fluorescence probe is carried out.Streptomycin sulfate can enhance the fluorescence intensity of Ag2Se QDs to some extent. The relative fluorescence enhancement degree I of Ag2Se QDs shows a good linear relationship with that of streptomycin sulfate in the range of 2.5 脳 10 ~ (-7) 10~(-7)mol/L.The linear equation: I = 0.009 1.032C, the linear correlation coefficient R = 0.9971AgSs QDs is 1.99 脳 10~(-7)mol/L.Ag_2Se quantum dot and streptomycin sulfate has a linear relationship with streptomycin sulfate in the range of 5 脳 10 ~ (-7) 10~(-7)mol/L.The linear equation: I = 0.791 0.064C, and the linear correlation coefficient RV 0.9979 AgSe QDs for streptomycin sulfate is 2.3 脳 10 ~ (-1) ~ (-7) mol 路L ~ (-1) 路L ~ (-1) 路min ~ (-1) ~ (-1) 路L ~ (-1) 路L ~ (-1).
【学位授予单位】：桂林理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.3

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