上转换发光检测方法在胆碱分析中的应用与研究

发布时间：2018-08-31 14:57

【摘要】：近年来,由于经济利益的驱使、科学知识的匮乏以及监督体制的漏洞,出现了许许多多的食品质量安全问题,随着这些重大食品安全问题的曝光,人们也越来越关注食品质量安全与膳食营养等问题。现如今的许多化学分析方法均已被许多研究者深入研究,很多方法已经趋于成熟,但是仍有许多问题不能够突破,如果想要得到更简便、快捷、灵敏的分析方法,就要开发新的方式。上转换荧光分析是一种比较先进的化学分析方法,上转换纳米发光材料的最大特点是:化学性质稳定、无毒、无光闪烁和光漂泊以及近红外激发。现如今,应用上转换荧光分析的方法检测食品中的有益有害物质并不多见,本文致力于建立一种食品检测方法,将上转换荧光分析的方法与之融合,开发一种全新的、简便的、灵敏的食品检测方法。(1)基于苯胺单体在上转换纳米粒子表面原位聚合的检测方法的建立:本文合成了一种上转换发光纳米材料(Na YF4:Yb~(3+)/Er~(3+)纳米粒子)并在表面以聚丙烯酸(PAA MW=1800)包裹。本文建立了基于聚苯胺使上转换纳米粒子荧光淬灭的检测方法。胆碱在37℃下通过胆碱氧化酶催化而分解成过氧化氢(H2O2)和甜菜碱。在p H 3.0的环境下苯胺单体的正电荷与上转换纳米粒子表面上的负电荷发生静电相互作用,并且在HRP和H2O2的存在下,使得苯胺单体在上转换纳米粒子的表面上原位聚合形成聚苯胺后,上转换纳米粒子荧光淬灭。根据荧光光谱图,可以分析样品中H2O2和胆碱的含量。胆碱的检测浓度范围为1-200μM,检出限为50 n M。在婴儿配方奶粉以及鸡蛋中进行了实际应用,对胆碱检测的回收率在97.7%-102.7%之间。这种上转换发光检测方法不仅可以避免其他荧光物质的干扰,还具有选择性高、灵敏、快捷、操作简单的特点。(2)基于三价铁离子淬灭上转换纳米荧光材料的检测方法的建立:本文合成了一种上转换纳米荧光材料(Na YF4:Yb~(3+)/Tm~(3+)纳米粒子)并在表面以聚丙烯酸(PAA MW=1800)包裹。试验中发现三价铁离子对上转换发光纳米材料具有明显的淬灭效应,而其他常见离子对其荧光不产生明显影响。另外,过氧化氢(H2O2)可以将二价铁离子(Fe2+)氧化成三价铁离子(Fe~(3+)),这从而能使上转换纳米材料荧光淬灭。基于此,我们开发了一种新的过氧化氢检测方法。因为胆碱在37℃下通过胆碱氧化酶的催化分解成H2O2和甜菜碱,然后H2O2可以将二价铁离子氧化为三价铁离子,三价铁离子进一步使上转换纳米材料荧光淬灭。因此,我们开发了胆碱的检测方法。根据荧光光谱图,可以分析样品中H2O2和胆碱的含量。H2O2的检测浓度范围为0.25-5μM,检出限为0.1μM。胆碱的检测浓度范围为1-60μM,检出限为0.5μM。在婴儿配方奶粉进行了实际应用,对胆碱检测的回收率在95.0%-100.07%之间。这种使用近红外光进行测试的方法在生物分析中具有重要意义,它也可用于测试其他有机物质和反应,在生物体中产生过氧化氢。这种检测方法具有选择性高、灵敏、快捷、操作简单的特点。
[Abstract]:In recent years, driven by economic interests, lack of scientific knowledge and loopholes in the supervision system, there have been many food quality and safety problems. With the exposure of these major food safety issues, people are increasingly concerned about food quality and safety and dietary nutrition. Now many chemical analysis methods have been approved. Up-conversion fluorescence analysis is a relatively advanced chemical analysis method. The most important characteristics of up-conversion nanoluminescent materials are chemical properties. Nowadays, it is rare to use up-conversion fluorescence analysis to detect the beneficial and harmful substances in food. This paper is devoted to establish a food detection method, which combines up-conversion fluorescence analysis with it to develop a new, simple and sensitive food. Detection methods. (1) Based on the in-situ polymerization of aniline monomers on the surface of upconversion nanoparticles, a novel upconversion luminescent nanomaterial (Na YF4: Yb ~ (3 +) / Er ~ (3 +) nanoparticles) was synthesized and coated with polyacrylic acid (PAA MW = 1800). A fluorescence quenching method for upconversion nanoparticles based on polyaniline was established. Detection method. Choline is decomposed into hydrogen peroxide (H2O2) and betaine catalyzed by choline oxidase at 37 C. The positive charge of aniline monomer interacts electrostatically with the negative charge on the surface of upconversion nanoparticles in the presence of HRP and H2O2, enabling the aniline monomer to be on the surface of upconversion nanoparticles. According to the fluorescence spectrum, the content of H2O2 and choline in the sample can be analyzed. The detection concentration range of choline is 1-200 mu M, and the detection limit is 50 N M. It has been applied in infant formula milk powder and eggs. The recovery of choline detection is 97.7% - 102.7%. (2) Based on the determination method of up-conversion Nanofluorescent materials by ferric ion quenching, a novel up-conversion Nanofluorescent material (Na YF4: Yb ~ (3 +) / Tm ~ (3 +) nanometer was synthesized. In addition, hydrogen peroxide (H2O2) can oxidize divalent iron ions (Fe2 +) to trivalent iron ions (Fe 3 +), which leads to an obvious quenching effect. Based on this, we developed a new method for the determination of hydrogen peroxide. Choline is decomposed into H2O2 and betaine by choline oxidase catalysis at 37 C, and then H2O2 oxidizes divalent iron ions to trivalent iron ions. Trivalent iron ions further quench the fluorescence of up-conversion nanomaterials. Therefore, we have developed a method for the determination of choline. According to the fluorescence spectrogram, the content of H2O2 and choline in the sample can be analyzed. The detection concentration range of H2O2 is 0.25-5 mu M, the detection limit is 0.1 mu M. The detection concentration range of choline is 1-60 mu M, the detection limit is 0.5 mu M. In the range of 95.0%-100.07%. This method is of great significance in biological analysis. It can also be used to test other organic substances and reactions and produce hydrogen peroxide in organisms. This method has the characteristics of high selectivity, sensitivity, rapidity and simple operation.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.3;TS207.3

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