金属纳米簇的合成与光分析应用

发布时间：2018-04-19 14:00

  本文选题：铜纳米簇 + 金纳米簇　； 参考：《湘潭大学》2017年硕士论文

【摘要】：金属纳米簇是一种新型的纳米材料。它具有尺寸小、稳定性好、斯托克斯位移大、生物相容性好等优点,近年来被广泛地应用于分析化学。ABTS是一种过氧化氢酶的底物,ABTS/ABTS+的氧化还原电位为0.68 V,容易发生电子转移,生成稳定的绿色自由基能进行可视化检测方面,被作为光学探针广泛应用于生物、化学等各个领域。适配体是一小段经体外筛选得到的寡核苷酸序列,能与相应的目标物质进行高度特异性结合,同时可作为模板合成金属纳米簇。本文主要完成了金属纳米簇的制备、表征及其分析应用等实验内容。具体概述如下:(1)合成了以二硫苏糖醇(DTT)为模板的铜纳米簇和柠檬酸稳定的纳米银,分别采用紫外-可见分光光度法、荧光光谱法等方法进行了表征。通过内滤效应,纳米银能使铜纳米簇的荧光发生猝灭,加入三聚氰胺后,由于三聚氰胺使纳米银团聚,内滤光作用被破坏,铜纳米簇荧光恢复。实验结果表明,三聚氰胺浓度在4-28μM范围内,体系的荧光恢复程度与三聚氰胺的浓度存在良好的线性关系,检出限为0.98μM,实际样品(牛奶)的加标回收率为96.5%-103.8%。(2)合成了以氯霉素适配体为模板的铜纳米簇,基于合成的DNA铜纳米簇在核酸外切酶Ⅰ(Exo Ⅰ)的作用下导致模板破坏而荧光猝灭,同时二价铜离子在过氧化氢以及肌酸肝的共同作用下会使ABTS被氧化成绿色的ABTS+,则可通过荧光、紫外以及目视检测Exo Ⅰ。实验结果表明,当Exo Ⅰ的浓度在0.1-10 U mL-1范围内,体系的荧光强度与Exo Ⅰ浓度存在着很好的线性关系,检出限为0.08 U mL-1,实际样品(血清)加标回收率为92.4%-103.7%。(3)合成了以DNA为模板的金纳米簇,合成的DNA金纳米簇在过氧化氢和亚铁离子的芬顿反应作用下导致模板破坏而荧光猝灭,同时三价金离子会使ABTS被氧化成绿色的ABTS+,则可通过荧光、紫外以及目视检测羟基自由基。实验结果表明,当过氧化氢浓度在2-15μM范围内,体系的荧光相对强度F0-F与过氧化氢浓度存在着很好的线性关系。检出限为1.5μM,对于实际样品(血清)的加标回收率为90.6%-108.6%。
[Abstract]:Metal nanoclusters are a new type of nanomaterials.It has the advantages of small size, good stability, large Stokes shift and good biocompatibility. In recent years, it has been widely used in analytical chemistry. ABTS is a kind of catalase substrate. The redox potential of ABTS / ABTS is 0.68 V, which makes it easy to transfer electrons.The generation of stable green free radicals for visual detection is widely used as optical probes in biological, chemical and other fields.Aptamer is a small sequence of oligonucleotides screened in vitro, which can bind to the target material with high specificity and can be used as a template for the synthesis of metal nanoclusters.In this paper, the preparation, characterization and application of metal nanoclusters were studied.The copper nanoclusters and citric acid stabilized silver nanoparticles were synthesized and characterized by UV-Vis spectrophotometry and fluorescence spectrometry respectively.Through internal filtration, nano-silver can quench the fluorescence of copper nanoclusters. After the addition of melamine, the silver nanoparticles are agglomerated by melamine, the internal filter is destroyed, and the fluorescence of copper nanoclusters recovers.The experimental results show that there is a good linear relationship between the fluorescence recovery degree of the system and the concentration of melamine in the range of 4-28 渭 M.Copper nanoclusters with chloramphenicol aptamer as template were synthesized with the detection limit of 0.98 渭 m and the standard recovery of actual samples (milk) of 96.5- 103.8. the results showed that the synthesized DNA copper nanoclusters caused template destruction and fluorescence quenching under the action of nucleic acid exonuclease 鈪，

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