表面增强拉曼光谱技术在汞离子检测中应用研究

发布时间：2018-01-06 08:28

本文关键词：表面增强拉曼光谱技术在汞离子检测中应用研究　出处：《合肥工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：重金属汞离子(Hg2+)是对人类和动植物具有很大毒害作用的金属元素,对人的肾、肝脏等组织以及神经系统等都可产生严重的损害作用,直接威胁了食品和环境安全。因此,建立快速、灵敏、便捷的汞离子检测方法对保护人类健康具有重要作用。本文所介绍了以下三种检测方法：(1)基于侧向层析技术的表面增强拉曼光谱Hg2+检测法本文基于经典的T-Hg2+-T识别系统,在表面标记了拉曼信号分子的金纳米粒子(AuNPs)表面组装了富含T碱基Hg2+核酸适配体,利用T-Hg2+-T错配与同样富含T碱基的测试线(T线)上标记的核酸探针结合而被捕获显线,通过碱基互补配对被标记在质控线(C线)上的核酸探针捕获显线,通过肉眼观察显线强度初步定性分析待测体系中Hg2+浓度,而通过拉曼光谱分析,对肉眼分辨不出来的范围也能检测出其信号强度,从而在层析技术的基础上提高了检测灵敏度,通过优化选择以Au@Ag核壳结构作为基底材料,比单纯的(AuNPs)作为基底拉曼信号增强的效果好,最终灵敏度可达到0.1 ppb。(2)传统型表面增强拉曼光谱Hg2+检测方法本方法也是建立在Hg2+核酸适配体的基础上,在表面标记了拉曼信号分子的AuNPs上组装Hg2+核酸适配体,通过识别Hg2+后以T-Hg2+-T的结合拉近金纳米粒子之间距离,粒子之间形成热点,该位置处电磁场强度较强,处于热点区域的拉曼信号分子的信号也有所提高,在有Hg2+存在时进行拉曼信号强度检测,使其检测灵敏度远远高于比色法,拉曼检测的灵敏度为0.01nM,在汞离子浓度为10-11-10-8M时,拉曼信号强度与汞离子浓度的对数呈现良好线性关系。(3)信号增敏型表面增强拉曼光谱Hg2+检测方法在传统拉曼检测的基础上,通过一对相互互补的寡核苷酸探针,在AuNPs表面再组装小粒径的银纳米粒子(AgNPs),增加并增强两金纳米粒子之间热点处电磁场强度,使拉曼信号分子信号进一步提高而达到增敏效果,对两种纳米粒子比例以及互补探针浓度优化,增敏后对汞的检测灵敏度提高到0.01 pM,在10-12-10-8M的浓度范围内,拉曼信号强度与汞离子浓度的对数也是呈良好线性。
[Abstract]:Hg2) is a metal element that has a great toxic effect on human beings, animals and plants. It can cause serious damage to human kidney, liver and nervous system. A direct threat to food and environmental safety. Therefore, the establishment of fast, sensitive. The convenient method of mercury ion detection plays an important role in the protection of human health. This paper introduces the following three detection methods: 1). Surface enhanced Raman Spectroscopy (Hg2) Detection based on Lateral Chromatography this paper is based on the classical T-Hg2-T recognition system. On the surface of au nanoparticles labeled with Raman signal molecules, the aptamers of Hg2 nucleic acid rich in T bases were assembled. The T-Hg2-T mismatch was combined with the labeled nucleic acid probe on the test line, which is also rich in T bases. The nucleic acid probe labeled on the quality control line C line by complementary pair of base pairs was used to capture the display line. The Hg2 concentration in the system was analyzed qualitatively by observing the intensity of the display line with naked eye, and the Raman spectrum was used to analyze it. The signal intensity can also be detected for the range which can not be distinguished by the naked eye, so the detection sensitivity is improved on the basis of chromatographic technology, and the Au@Ag core-shell structure is selected as the substrate material by optimizing the selection. Compared with the pure AuNPs, the enhancement effect of the substrate Raman signal is better than that of the pure AuNPs. The traditional surface-enhanced Raman spectroscopy (Hg2) method is based on the aptamer of Hg2 nucleic acid. The aptamer of Hg2 nucleic acid was assembled on the surface of AuNPs labeled with Raman signal molecule, and the distance between gold nanoparticles was reduced by T-Hg2-T binding after Hg2 recognition. A hot spot is formed between the particles, and the intensity of the electric magnetic field is strong at this position, and the signal of Raman signal molecule in the hot spot region is also improved. The intensity of the Raman signal is detected in the presence of Hg2. The sensitivity of the method is much higher than that of colorimetric method. The sensitivity of Raman detection is 0.01nM, when the concentration of mercury ion is 10-11-10-8M. There is a good linear relationship between the intensity of Raman signal and the logarithm of mercury ion concentration. The signal sensitized surface-enhanced Raman spectroscopy (Hg2) detection method is based on the traditional Raman detection method. A pair of complementary oligonucleotide probes were used to reassemble small silver nanoparticles (AgNPs) on the surface of AuNPs to increase and enhance the electric field intensity at the hot spot between the two gold nanoparticles. The ratio of two nanoparticles and the concentration of complementary probe were optimized to increase the sensitivity of mercury detection to 0.01 pm. In the range of 10-12 ~ (-8) M, the logarithm of Raman signal intensity and mercury ion concentration is also linear.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TS207.3;O657.37

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