基于分子印迹技术与电化学传感技术的结合与应用研究

发布时间：2018-03-22 17:50

本文选题：电化学传感器　切入点：分子印迹聚合物　出处：《石河子大学》2017年硕士论文　论文类型：学位论文

【摘要】：本工作将分子印迹技术(Molecular imprinting techniqu,MIT)与电化学传感技术相结合,制备了多种分子印迹聚合物(Molecularly imprinted polymer,MIP)修饰的电化学传感器,并用于抗菌药物、生物体内源性物质和神经递质等的检测工作中,并且深入的对比了分子印迹-电催化反应和分子印迹-门效应两种检测原理,考察了上述两种检测方法对于检测性能的影响。具体工作概述如下:(1)基于不同检测原理的甲硝唑分子印迹电化学传感器的制备和应用。以玻碳电极(Glass carbon electrode,GCE)作为工作电极,甲硝唑为模板分子,采用电聚合的方法在GCE表面修饰了MIP。将所制备的甲硝唑电化学传感器(MIP/GCE)用于生物样品中甲硝唑的含量检测。对聚合过程中的功能单体进行了优化,采用循环伏安法(Cyclic voltammetry,CV)和电化学阻抗法(Electrochemical impedance spectroscopy,EIS)表征和评估了传感器的性能。最终本文采用同一个电极,基于两种不同的检测原理,完成了对甲硝唑的含量测定工作。两种检测方法,一种是基于分子印迹-电催化反应的方法(方法Ⅰ),另一种则是基于分子印迹-门效应方法(方法Ⅱ)。系统地比较了两种检测方法在检测范围、灵敏度、精密度、传感器的选择性、重复性和长期稳定性等方面的差别。检测结果表明,方法Ⅰ具有较低的检测限,其检测限为3.33×10-10 mol/L(S/N=3),而方法Ⅱ的检测限为6.67×10-10 mol/L(S/N=3)。而方法Ⅰ和方法Ⅱ的线性范围分别为1.0×10-9?1.0×10-8mol/L和2.0×10-9~1.0×10-7 mol/L,方法Ⅱ具有更宽的检测范围。最后将两种方法应用于生物样品中甲硝唑的测定。(2)还原型与氧化型谷胱甘肽分子印迹电化学传感器的制备和应用。本章以细胞中还原型谷胱甘肽(GSH)和氧化型谷胱甘肽(GSSG)为模板分子,以邻苯二胺(o-phenylenediamine,o-PD)为功能单体,在金电极表面(Gold electrode,GE)电聚合MIP,分别制备了GSH和GSSG的印迹聚合物修饰的电化学传感器(GSH-MIP/GE和GSSG-MIP/GE),用于两者的含量测定。采用CV和EIS对传感器的制备过程进行了跟踪,对传感性能进行了考察。检测结果表明,传感器对两种谷胱甘肽在4×10-10 mol/L~2×10-8 mol/L范围内呈现出良好的线性,检测限均为1.33×10-10 mol/L(S/N=3)。选择性实验表明,在有结构类似物或其他干扰物的存在下,传感器对GSH或GSSG的检测结果几乎没有变化。随后将所制备的传感器应用于细胞样品中GSH和GSSG的检测,回收率在92.0~109.1%,与标准检测方法结果一致,表明传感器的结果准确可靠。最终用不同浓度的砷化物处理HL-60细胞后,用传感器测定了其中GSH和GSSG的含量变化,发现传感方法比标准检测方法更为灵敏,可以给出痕量(nmol/L级别)谷胱甘肽的准确浓度,比标准方法更具优势。(3)分子印迹和碳纳米管/石墨烯泡沫复合膜修饰的多巴胺电化学传感器的制备和应用。以3D网状结构的石墨烯(Graphene foam,GF)与碳纳米管(Carbon nanotube,CNT)形成的复合材料(CNT/GF)作为无支撑的工作电极,在其表面修饰MIP,构建多巴胺(Dopamine,DA)分子印迹聚合物修饰的电化学传感器(DA-MIP/CNT/GF),用于DA的含量检测。CNT/GF的制备采用牺牲模板法,以镍网为模板,在其表面采用等离子体增强化学气相沉积法生长GF和CNT,继而除去镍网制备而得。随后在CNT/GF/表面电聚合一层以DA为模板分子的MIP,即完成了MIP/CNT/GF电化学工作电极的构建。通过扫描电子显微镜对CNT/GF和镍骨架进行了形貌表征,采用CV和EIS等方法对复合电极的制备过程进行了跟踪,对传感器的性能进行考察。该复合电极的突出优点有:1)不依赖于商品化的电极,节约成本;2)拥有三维结构的CNT/GF电极作为MIP的基底具有扩大传感器表面积的作用,从而提高了电极的灵敏度;3)MIP为整个传感系统提供了优良的分子识别性能,保证了电极的选择性。检测结果表明,DA在2×10-15到1×10-12 mol/L浓度范围内与响应电流呈良好的线性关系,检测限为6.67×10-16 mol/L(S/N=3)。此外,该传感器表现出良好的选择性和抗干扰性,在复杂样品中也能准确检测目标物质DA。
[Abstract]:The molecular imprinting technique (Molecular imprinting techniqu, MIT) combined with electrochemical sensor technology, a variety of molecular imprinting polymer was prepared (Molecularly imprinted, polymer, MIP) of electrochemical sensor, and used antibiotics, detection of endogenous substances and neurotransmitters, and in-depth comparison of two kinds of the detection principle of molecular imprinting and electro catalytic reaction and molecular imprinting - door effect, the effects of the two kinds of detection methods for detection performance. The specific work is summarized as follows: (1) Different Molecular Imprinted Electrochemical Sensor metronidazole detection principle, preparation and application. Based on the glassy carbon electrode (Glass carbon, electrode, GCE) as the working electrode, metronidazole as template molecule by electropolymerization on the surface of GCE MIP. modified the electrochemical preparation of metronidazole sensor (MIP/GCE) for students Determination of metronidazole compound in the sample. The polymerization process of functional monomers were optimized by cyclic voltammetry (Cyclic voltammetry, CV) and electrochemical impedance spectroscopy (Electrochemical impedance spectroscopy, EIS) to characterize and evaluate the performance of the sensor. Finally this paper uses the same electrode, two different detection principle based on the complete content of metronidazole determination. Two kinds of detection methods, a method of molecular imprinting and electrocatalytic reactions based on (Fang Fa), the other is the molecular imprinting method based on door effect (method II). Systematic comparison of two methods in the detection range, sensitivity, precision of sensor selectivity, repeatability and long-term stability and other aspects of the difference. The detection results show that the method has low detection limit, the detection limit is 3.33 * 10-10 mol/L (S/N=3), and the detection limit of method 2 is 6. 67 x 10-10 mol/L (S/N=3). The linear range of the method I and method II were 1 x 10-9? 1 * 10-8mol/L and 2 * 10-9~1.0 * 10-7 mol/L, with a wider range of detection methods II. Finally, two methods are applied to the determination of metronidazole in biological samples. (2) preparation and Application the prototype and oxidative glutathione Molecularly Imprinted Electrochemical sensor system. In this chapter, cellular glutathione (GSH) and oxidized glutathione (GSSG) as the template molecule, with adjacent benzene two amines (o-phenylenediamine, o-PD) as the functional monomer on the surface of the gold electrode (Gold electrode GE) Electropolymer MIP were prepared by the electrochemical sensor imprinted polymer modified GSH and GSSG's (GSH-MIP/GE and GSSG-MIP/GE), for the determination of the content of the preparation process. By using CV and EIS to the sensor system for tracking, the sensing performance of the inspection. The detection results show that the sensor To exhibit good linearity of two glutathione in 4 * 10-10 mol/L~2 * 10-8 mol/L range, the detection limit is 1.33 * 10-10 mol/L (S/N=3). Selective experiments show that in structural analogues or other interventions in the presence of GSH or GSSG sensor detection results almost no change. Then detection for sensor applications prepared in GSH and GSSG cells in the sample, the recovery rate was 92.0~109.1%. The results were consistent with the standard detection methods indicates that the sensor is accurate and reliable. Finally with different concentrations of arsenic in HL-60 cells after treatment, the GSH and GSSG content were measured by the sensor, found the sensing method than the standard the detection method is more sensitive, can be given trace (nmol/L level) accurate concentration of glutathione, has more advantage than the standard method. (3) dopamine molecular imprinting and carbon nanotubes / graphene composite film modified foam The preparation and application of chemical sensor system. The graphene 3D mesh structure (Graphene foam, GF) and carbon nanotubes (Carbon nanotube, CNT) composite formation (CNT/GF) as a working electrode without support, modification of MIP on the surface of dopamine (Dopamine, DA) to construct electrochemical sensor with molecular imprinted polymer modified (DA-MIP/CNT/GF), for measuring the content of.CNT/GF DA were prepared by sacrificial template method with nickel net as a template, on the surface by plasma enhanced chemical vapor deposition growth of GF and CNT, and then remove the nickel net prepared. Then a layer of polymerization using DA as template molecule on the surface of CNT/GF/ electric MIP that is, we constructed MIP/CNT/GF electrochemical working electrode. By scanning electron microscopy of CNT/GF and nickel skeleton were morphology characterization by CV and EIS methods of preparation process of composite electrode was tracked, the sensor of Can inspect. Advantages of the composite electrode are: 1) does not depend on the electrode in the commercialization of cost savings; 2) CNT/GF has a three-dimensional structure of the electrode as the MIP substrate has expanded sensor surface area, so as to improve the sensitivity of the electrodes; 3) MIP provides excellent performance for the molecular recognition the sensing system, to ensure the selectivity of the electrode. The detection results show that the DA in the 2 * 10-15 to 1 * 10-12 mol/L concentration range and response showed a good linear relationship between the current and the detection limit is 6.67 * 10-16 mol/L (S/N=3). In addition, the sensor exhibited good selectivity and anti-interference, can accurately detect the target material DA. in complex samples

【学位授予单位】：石河子大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212.3;R446.1

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