新型纳米材料构建的分子印迹电化学传感器的研究与应用

发布时间：2018-07-30 08:37

【摘要】：发展快速、灵敏、高选择性和检测结果可靠的传感器在诸多领域都有广泛需求,在药物分析领域也是同样。分子印迹聚合物(molecularly imprinted polymer,MIP)是一种能够特异性识别目标物质的高分子材料,具有预定选择性、特异识别性和广泛适用性的特点,因此近年来发展迅速。本论文将分子印迹技术与电化学传感技术相结合,制备了三种分子印迹电化学传感器分别用于检测雌酮硫酸钠、甲硝唑和多巴胺。主要内容分为以下3个部分:(1)基于分子印迹聚合物修饰的碳糊电极用于雌酮硫酸钠的检测本研究采用传统的本体聚合方法制备雌酮硫酸钠(estrone 3-sulfate sodium salt,ESS)分子印迹聚合物,将ESS-MIP和石墨粉混合后加入少量液体石蜡作为粘合剂,充分研磨将其混匀,随后填充到电极管中,制备了分子印迹聚合物修饰的碳糊电极(carbon paste electrode,CPE),将其作为电化学传感器用于ESS的检测。其中,对ESS-MIP制备过程中模板分子、功能单体、交联剂三者之间的比例、聚合反应溶剂和洗脱溶剂都进行了优化,同时对填入碳糊电极中聚合物与石墨粉的质量比进行了优化。通过扫描电子显微镜和傅里叶红外光谱仪对所制备的印迹聚合物材料的形貌和结构进行了表征。在最佳条件下,所构建的传感器对ESS的检测具有较好的选择性和宽的线性范围(4.0×10-12~6.0×10-9 M),检测限可达1.2×10-12 M(S/N=3)。此外,传感器被成功应用于实际孕马尿样品中ESS的检测,与高效液相色谱法进行比对发现,结果准确可信,重复性好,检测迅速,成本低廉,有望在现场实时检测中发挥作用。(2)基于分子印迹聚合物修饰的纳米多孔微线用于检测甲硝唑本工作采用金银合金线(Au-Ag alloy microrod,AMR),通过简单的脱合金法得到表面具有纳米多孔结构的金银合金线(nanoporous Au-Ag alloy microrod,NPAMR),将其作为工作电极,利用电聚合的方式在其表面修饰上分子印迹聚合物薄膜,得到分子印迹聚合物修饰的纳米多孔金银合金线(MIP/NPAMR)电极。该电极可以在没有任何额外商品化电极支撑下作为工作电极使用,本工作采用这种无支撑电极完成了甲硝唑(metronidazole,MNZ)的定量分析。对传感器制备过程中的一系列实验参数进行了优化。通过扫描电子显微镜和能谱分析对MNZ-MIP/NPAMR进行了形貌表征以及元素分析,用计时电量法对脱合金前后传感器的表面积进行了计算,结果表明具有3D结构的NPAMR具有高的比表面积和良好的电子传递能力。将[Fe(CN)6]3-/4-氧化还原对作为电流指示剂,采用循环伏安法对目标分子MNZ进行了定量分析并考察了MNZ-MIP/NPAMR的各项电化学性能。实验结果表明所构建的传感器具有超低的检测限(2.7×10-14 M)和宽的线性范围(8.0×10-14~1.0×10-6 M),不需要额外商品化电极支撑的特点也有利于降低成本。此外,传感器被成功应用于实际样品(鱼肉和片剂)中MNZ的检测,结果准确可信,重复性好,检测迅速,有望在更多生物和化学物质的痕量检测中发挥作用。(3)基于分子印迹聚合物修饰的纳米多孔微线用于检测痕量多巴胺本工作中纳米多孔金银合金微线的制备方法同(2),同样采用电聚合的方法,以多巴胺(dopamine,DA)为模板分子,在NPAMR表面形成了一层分子印迹聚合物膜,经过洗脱之后得到MIP修饰的电化学传感器(MIP/NPAMR)。对聚合过程中聚合液的pH值和模板分子与功能单体之间的比例进行了优化。通过扫描电子显微镜对NPAMR和MIP/NPAMR进行了形貌表征,用能谱分析对NPAMR和MIP/NPAMR中元素组成进行了分析,通过循环伏安法和阻抗分析法对MIP/NPAMR的各项电化学性能进行了评价。实验结果表明所构建的电化学传感器具有超低检测限(7.63×10-14 M)和宽的线性范围(2.0×10-13~2.0×10-8 M)。此外,传感器被成功应用于实际生物样品(家兔血清和大鼠脑组织)中DA的检测。
[Abstract]:Molecularly imprinted polymer (MIP) is a high molecular material capable of identifying target substances specifically, with predetermined selectivity, specificity and wide suitability. In this paper, three kinds of molecularly imprinted electrochemical sensors are prepared and used to detect sodium estrone sulfate, metronidazole and dopamine, which are divided into 3 parts: (1) carbon paste electrode based on molecularly imprinted polymer modified by molecular imprinting technology. In the study of the test of estrone sodium sulfate, the traditional bulk polymerization method was used to prepare estrone 3-sulfate sodium salt (ESS) molecularly imprinted polymer, and a small amount of liquid paraffin was mixed with ESS-MIP and graphite powder as adhesive, and it was mixed well and then filled into the electrode tube, and the molecularly imprinted polymerization was prepared. The modified carbon paste electrode (carbon paste electrode, CPE) is used as an electrochemical sensor for the detection of ESS. Among them, the proportion of the template molecules, functional monomers, crosslinker three, the polymerization reaction solvent and the elution solvent in the ESS-MIP preparation process are optimized, and the polymer and graphite powder in the carbon paste electrode are filled. The mass ratio is optimized. The morphology and structure of the imprinted polymer materials are characterized by scanning electron microscope and Fourier infrared spectrometer. Under the optimum conditions, the sensor has good selectivity and wide linear range (4 x 10-12~6.0 x 10-9 M) for the detection of ESS, and the detection limit is up to 1.2 * 10-12. M (S/N=3). In addition, the sensor has been successfully applied to the detection of ESS in real pregnant horse urine samples. Compared with high performance liquid chromatography (HPLC), it is found that the results are accurate, reliable, reproducible, rapid and inexpensive, and it is expected to play a role in real time detection. (2) nano porous microlines based on molecularly imprinted polymer are used to detect the nail. The Au-Ag alloy microrod (AMR) is used in nitrazole to obtain the gold and silver alloy wires (nanoporous Au-Ag alloy microrod, NPAMR) on the surface of the surface with a simple dealloying method, which is used as the working electrode to modify the molecularly imprinted polymer film on its surface by electropolymerization, and the molecular imprint is obtained. A trace polymer modified nano porous gold and silver alloy wire (MIP/NPAMR) electrode. The electrode can be used as a working electrode without any additional commercialized electrode support. This work uses this unsupported electrode to complete the quantitative analysis of metronidazole (metronidazole, MNZ). A series of experimental parameters in the process of sensor preparation are carried out. The morphology and elemental analysis of MNZ-MIP/NPAMR were carried out by scanning electron microscope and energy spectrum analysis. The surface area of the Dealloyed sensor was calculated by chronoelectric method. The results showed that the NPAMR with 3D structure had high specific surface area and good electron transfer ability. [Fe (CN) 6]3-/4- was redox and redox. As an current indicator, the target molecule MNZ is quantitatively analyzed by cyclic voltammetry and the electrochemical performance of MNZ-MIP/NPAMR is investigated. The experimental results show that the sensor has a ultra low detection limit (2.7 x 10-14 M) and a wide linear range (8 x 10-14~ 1 x 10-6 M) without additional commercial electrode support. The characteristics also help to reduce the cost. In addition, the sensor has been successfully applied to the detection of MNZ in real samples (fish and tablets). The results are accurate, reproducible, and rapid detection. It is expected to play a role in the trace detection of more biological and chemical substances. (3) nano porous microlines based on molecularly imprinted polymer are used to detect trace amounts. The preparation method of nano porous gold and silver alloy microwires in dopamine is the same as (2). Also, the method of electropolymerization, using dopamine (dopamine, DA) as the template molecule, has formed a layer of molecularly imprinted polymer film on the surface of NPAMR. After elution, the MIP modified electrochemical sensor (MIP/NPAMR) is obtained. The pH of the polymerization solution in the polymerization process. The ratio of the value and the template molecule to the functional monomer was optimized. The morphology of NPAMR and MIP/NPAMR was characterized by scanning electron microscope. The composition of the elements in NPAMR and MIP/NPAMR was analyzed by energy spectrum analysis. The electrochemical properties of MIP/NPAMR were evaluated by cyclic voltammetry and impedance analysis. The results show that the proposed electrochemical sensor has a ultra low detection limit (7.63 x 10-14 M) and a wide linear range (2 x 10-13~2.0 * 10-8 M). In addition, the sensor has been successfully applied to the detection of DA in the actual biological samples (rabbit serum and rat brain tissue).
【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

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