金阵列电化学免疫传感器检测大肠杆菌的研究

发布时间：2018-04-20 02:39

本文选题：免疫传感器 + 电化学传感器　；参考：《浙江大学》2006年硕士论文

【摘要】：本课题的研究成功地实现了电化学免疫阵列传感器快速检测肠出血性大肠杆菌O157:H7。利用巯基物质在金表面的自组装特性,在金阵列上形成稳定、有序、紧密的,尾基为羧基的16-巯基十六烷酸(MHDA)自组装膜(Self-assembled Monolayers,SAMs);通过1-乙基-3-(3-二甲基氨丙酸)碳二亚胺/N-羟基琥珀酰亚胺(EDC/NHS)的活化作用在电极表面形成活性酯中间体,使抗体更有效的固定到SAMs上;因抗原抗体的特异性结合,将大肠杆菌O157:H7捕获到电极上,进行电化学测量,从而实现了对细菌的定量检测。在存在铁氰化钾/亚铁氰化钾氧化还原对的缓冲溶液中,测量电极各步处理结果的循环伏安曲线和电化学阻抗谱。循环伏安曲线可用来定性的分析电极表面的修饰状况以及修饰层的稳定性。根据电化学阻抗谱良好的界面表征特性,选取合适的等效电路对阻抗谱进行分析。相对常相位角元件,电子转移电阻的改变最明显,增幅最大。从而可以确定,免疫传感器的修饰以及大肠杆菌的固定主要影响了电子转移电阻。通过分析电子转移电阻在不同浓度菌液中响应的变化,实现对浓度的定量分析。检测过程中金电极阵列的使用,给多样本检测节省了时间。该免疫传感器的检测下限可达到2.0×10~2 CFU/ml,检测线性范围为2.0×10~2～2.0×10~7 CFU/ml。单个样本的检测时间仅需65分钟。
[Abstract]:In this paper, electrochemical immunosensor was successfully used to detect EHEC O 157: h 7. Based on the self-assembly properties of thiol compounds on gold surface, a stable, ordered, compact, carboxyl Cetadecanoic acid (MHDA) self-assembled self-assembled film was formed on gold arrays. MonolayersThe active ester intermediates were formed on the surface of the electrode by the activation of 1-ethyl-3-trimethylpropionic acid) carbodiimide / N-hydroxy-succinimide (EDCN / NHS) on the surface of the electrode, which made the antibody more effectively immobilized on the SAMs; because of the specific binding of the antigen and antibody, The Escherichia coli O157:H7 was captured on the electrode for electrochemical measurement, thus the quantitative detection of bacteria was realized. The cyclic voltammetry curves and electrochemical impedance spectra of the electrode were measured in the buffer solution with redox pairs of potassium ferricyanide / potassium ferricyanide. Cyclic voltammetry curves can be used to qualitatively analyze the surface modification and the stability of the modified layer. According to the good interface characterization characteristics of electrochemical impedance spectroscopy, the appropriate equivalent circuit is selected to analyze the impedance spectrum. Compared with the constant phase angle element, the change of the electron transfer resistance is the most obvious and the increase is the largest. It can be concluded that the modification of the immunosensor and the fixation of Escherichia coli mainly affect the electron transfer resistance. The quantitative analysis of electron transfer resistance was realized by analyzing the response of electron transfer resistance in different concentrations of bacteria. The use of gold electrode array in the detection process saves time for multi-sample detection. The detection limit of the immunosensor can reach 2.0 脳 10 ~ (-2) CFU / ml, and the linear range is 2.0 脳 10 ~ (2) ~ (2) 脳 10 ~ (7) CFU / ml. The detection time for a single sample is only 65 minutes.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2006
【分类号】：R318.6;R378

【引证文献】