碳纳米材料增敏的食品中转基因成分电化学传感方法研究

发布时间：2018-03-02 19:28

本文选题：电化学DNA生物传感　切入点：纳米复合物　出处：《合肥工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来,随着转基因食品的出现,转基因食品的安全问题成为公众担心的问题。转基因食品特定碱基序列的检测越来越重要。开发简便、迅速、廉价、微型化的DNA传感器成为了研究热点。电化学DNA传感器因其响应较快选择性好灵敏度高成本低等优点,成为了生物学、医学领域的新型课题。本文以特定转基因碱基序列为检测对象,利用血红素-还原氧化石墨烯(Hemin-rGO)纳米复合物、金纳米粒子(Au NPs)、多壁碳纳米管(WMCNTs)及硫堇-金纳米粒子(THi-Au NPs)等纳米材料修饰玻碳电极(GCE),构建了操作方便、灵敏度高、检测限低的新型电化学DNA生物传感器。对食品中转基因成分进行分析。本文研究内容主要包含以下四个部分:1.Hemin-rGO纳米复合物的制备及表征用氧化石墨及Hemin混合,然后加入还原剂水合肼及氨水,搅拌、油浴、离心清洗得到稳定存在的Hemin-rGO纳米复合物。用紫外-可见光光谱仪(UV-vis)和X射线光电子能谱分析(XPS)表征其结构及表面形态。用AuNPs和Hemin-rGO纳米复合物修饰GCE制备电化学传感器,并用电化学方法表征其电化学性能。2.基于Hemin-rGO纳米复合物和Au NPs的玻碳电极超低检测cDNA的无标记电化学基因传感器用Au NPs和Hemin-rGO纳米复合物修饰GCE制备电化学传感器。由HS-DNA与cDNA碱基互补配对成为双链DNA,阻断Hemin的氧化还原反应,使电流相应降低。在没有任何外部标签下,构建一个简单,灵敏和选择性好的传感平台检测cDNA。cDNA的浓度检测范围从1×10-18~1×10-13 M,系数为0.998,检出限达到1.41×10-19 M。该方法对样品施加和标准样品的回收百分比进行了验证。实验表明该传感器具有可靠性、高选择性、再生性等优点,是检测DNA的理想平台。3.THi-AuNPs-DNA纳米复合物的制备与表征将THi固定到由氯金酸还原的Au NPs表面,生成THi-Au NPs纳米复合材料。然后与经活化的巯基标记DNA(S1)混合,成功制备了THi-Au NPs-S1纳米复合材料。用紫外-可见光光谱仪对其结构及表面形态进行表征。并用电化学方法表征其电化学性能。4.基于氨基化的WMCNTs、THi-Au NPs-DNA纳米复合物及辣根过氧化物酶双重信号放大检测DNA技术基于氨基化的WMCNTs、Au NPs、THi及辣根过氧化物酶修饰GCE制备电化学DNA传感器。用辣根过氧化物酶催化过氧化氢的CV还原峰峰高来检测DNA,达到双重信号放大检测DNA的目的。该电化学DNA传感器的检出限是3.524×10-21 M,可在适当的检测条件下实现对转基因食品的DNA的检测。而且该电化学DNA传感器具有良好的选择性、稳定性、重现性和高的再生性。
[Abstract]:In recent years, with the emergence of genetically modified foods, the safety of genetically modified foods has become a public concern. The detection of specific base sequences of genetically modified foods is becoming more and more important. Miniaturized DNA sensors have become a research hotspot. Electrochemical DNA sensors have a fast response. Good selectivity? High sensitivity? Because of its low cost, it has become a new subject in biology and medicine. In this paper, we used heme-reduced graphene oxide (Hemin-rGOA) nanocomposites to detect specific transgenic base sequences. The glassy carbon electrode modified with gold nanoparticles, such as au NPsO, WMCNTsand THi-Au NPs), has been constructed for easy operation and high sensitivity. A novel electrochemical DNA biosensor with low detection limit was used to analyze the genetically modified components in food. The main contents of this paper are as follows: 1. The preparation and characterization of Hemin-rgo nanocomposites are mixed with graphite oxide and Hemin. Then add the reducing agent hydrazine hydrate and ammonia water, stir, oil bath, The structure and surface morphology of Hemin-rGO nanocomposites were characterized by UV-vis spectrometer and X-ray photoelectron spectroscopy (XPS). Electrochemical sensors were prepared by modifying GCE with AuNPs and Hemin-rGO nanocomposites. Electrochemical properties were characterized by electrochemical methods .2. Electrochemical sensors modified with au NPs and Hemin-rGO nanocomposites modified with au NPs and Hemin-rGO nanocomposites were prepared by glassy carbon electrode with ultra-low detection of cDNA based on Hemin-rGO nanocomposites and au NPs. HS-DNA and cDNA bases were paired to double strand DNA to block the redox reaction of Hemin. Reduce the current accordingly. Without any external label, build a simple, The detection range of cDNA.cDNA concentration on a sensitive and selective sensor platform is from 1 脳 10 ~ (-18) to 1 脳 10 ~ (-13) M, the coefficient is 0.998, and the detection limit is 1.41 脳 10 ~ (-19) M. this method is used to verify the application of the sample and the recovery percentage of the standard sample. The experimental results show that the sensor is reliable. High selectivity and reproducibility are the ideal platform for detecting DNA. 3. Preparation and characterization of THi-AuNPs-DNA nanocomposites. THi is immobilized on the surface of AuNPs reduced by chloruronic acid to form THi-AuNPs nanocomposites, and then mixed with activated mercapto labeled DNAS1. THi-Au NPs-S1 nanocomposites were successfully prepared. Their structures and surface morphology were characterized by UV-Vis spectrometer. The electrochemical properties of the nanocomposites were characterized by electrochemical method. 4. WMCNTsTsTHi-Au NPs-DNA nanocomposites and horseradish compounds based on amination. Peroxidase double signal Amplification Detection (DNA) technique based on Aminalized WMCNTsN au NPsNS-THi and horseradish peroxidase modified GCE to prepare electrochemical DNA sensor, GCE was used to detect the peak height of CV reduction peak of hydrogen peroxide catalyzed by horseradish peroxidase. The detection limit of the electrochemical DNA sensor is 3.524 脳 10 ~ (-21) M.It can be used to detect the DNA of transgenic food under appropriate detection conditions, and the electrochemical DNA sensor has good selectivity. Stability, reproducibility and high reproducibility.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TS207.3;O657.1

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