基于微纳结构电极界面可控组装的水产品质量安全检测传感器研究

发布时间：2018-06-02 07:17

  本文选题：微纳结构 + 可控组装　； 参考：《浙江大学》2017年博士论文

【摘要】：水产品质量安全是社会关注的热点之一。针对常见的危害因素,应寻找灵敏、准确、快速的检测技术。电化学传感器具有灵敏度好、选择性好、操作简单等优点,是最有前景的快速检测技术之一。其性能取决于电极材料及界面结构。对于不同目标分析物,应选择何种功能性材料以及如何控制纳米结构单元的组装,以获得预期的电极性能,是需要解决的关键问题。本论文分别以一维单壁碳纳米管(SWCNTs)、二维石墨烯和三维纳米多孔金(NPG)作为电极的基础组装材料,根据不同分析物,选择合适的功能性材料和可控的合成、组装方法,分别构建具有微纳结构电极界面的高性能传感器,并开展水产品质量安全检测的研究工作。主要的研究内容、结果和结论如下:(1)针对水产品新鲜度快速检测问题,首次提出基于介电泳(DEP)组装技术的等离子体氧化SWCNTs与聚(3,4-乙烯二氧噻吩)/聚苯乙烯磺酸(PEDOT/PSS)气敏薄膜的制备方法。结果表明,等离子体氧化处理能改善碳管的分散性,PEDOT/PSS可提高碳管的气敏性。经组装后碳管和聚合物链重新排序形成新的有序微纳结构,显著提高薄膜的导电性和气敏性。该传感器可检测鱼类腐败所释放的ppm级NH_3以及ppb级TMA和H_2S。(2)针对水产品Pb~(2+)快速检测问题,制备了电化学还原氧化石墨烯(ERGO)薄膜修饰的丝印电极。ERGO可改善电极的比表面积和电化学性能。该电极可线性检测5-200 μg/L Pb~(2+),灵敏度为93.36 μA μM-1 cm-2,检测下限为0.54μg/L(S/N=3)。(3)针对水产品Hg~(2+)快速检测问题,制备了基于电化学合金/去合金化法的NPG电极。合金/去合金化循环圈数决定电极的多孔结构及其对Hg~(2+)的溶出响应。该电极可线性测出1-030μg/LHg~(2+)。自组装硫醇化修饰电极表面可提高电极的灵敏度(32.92 μA/μM)和检测下限(0.098 μg/L,S/N=3)。(4)针对水产品NO_2~-快速检测问题,制备了基于电化学循环共沉积法的ERGO/金纳米颗粒(AuNPs)薄膜电极。ERGO可增大电极的比表面积,均匀分散在ERGO片之间的AuNPs可提高电极表面的导电性和电催化活性。电极对水产品中NO_2~-具有良好的线性响应区间(1-6000μM、6-20mM)、较高的灵敏度(0.3029、0.1522 μAμM-1 cm-2)以及较低的检测下限(0.13 μM,S/N=3)。(5)针对水产品单增李斯特菌(LM)灵敏检测问题,首次提出基于DEP组装羧基化石墨烯(CGR)/AuNPs薄膜免疫传感器的制备方法。DEP组装可控制CGR和AuNPs在电极表面的定位与排布,所得的CGR/AuNPs薄膜利于大量抗体的稳定固定。优化后的传感器可线性检测2-2×105 CFU/mL的LM,检测下限为 1CFU/mL(S/N=3)。上述研究成果为构建基于微纳结构电极界面的高性能传感器提供了新思路,也为食品质量安全快速检测提供技术支持。
[Abstract]:The quality and safety of aquatic products is one of the hot spots of social concern. In view of common hazard factors, sensitive, accurate and rapid detection techniques should be found. Electrochemical sensor has the advantages of good sensitivity, good selectivity and simple operation. It is one of the most promising rapid detection techniques. Its performance depends on the electrode material and interface structure. How to select the functional materials and how to control the assembly of nanostructure units to obtain the expected electrode performance are the key problems to be solved for different target analytes. In this thesis, one-dimensional single-walled carbon nanotubes (SWCNTsN), two-dimensional graphene and three-dimensional nano-porous gold (NPG) were used as the basic assembly materials of the electrode. According to the different analysis materials, suitable functional materials and controllable synthesis and assembly methods were selected. High performance sensors with micro / nano electrode interface were constructed, and the quality and safety of aquatic products were studied. The main research contents, results and conclusions are as follows: (1) aiming at the problem of rapid detection of freshness of aquatic products, The preparation method of plasma oxidized SWCNTs and PEDOT / PSSs based on dielectric electrophoresis (DEP) assembly technique is proposed for the first time. The results show that plasma oxidation can improve the dispersion of carbon tubes and PEDOT / PSS can improve the gas sensitivity of carbon tubes. After assembly, carbon tubes and polymer chains were rearranged to form a new ordered micro-nano structure, which significantly improved the conductivity and gas sensitivity of the films. The sensor detects ppm level NH_3 released by fish corruption and ppb class TMA and HSZ 2) for rapid detection of aquatic product Pb~(2. The electroreduction graphene oxide (ERG) film modified screen printing electrode. Ergo can improve the specific surface area and electrochemical performance of the electrode. The electrode can be used to detect 5-200 渭 g / L Pb~(2 with a sensitivity of 93.36 渭 A 渭 M-1 cm-2 and a detection limit of 0.54 渭 g / L ~ (-1) / N ~ (3). The NPG electrode based on electrochemical alloy / dealloying method has been prepared for rapid detection of Hg~(2 in aquatic products. The alloy / dealloying cycle circle number determines the porous structure of the electrode and its dissolution response to Hg~(2. The linear measurement of 1-030 渭 g/LHg~(2 can be obtained by this electrode. The self-assembled thiol modified electrode surface can improve the sensitivity of the electrode (32.92 渭 A / 渭 M) and the detection limit of 0.098 渭 g / L / N ~ (3) N ~ (3 +) for the problem of NO2- rapid detection of aquatic products. The ERGO/ gold nanoparticles AuNPs thin film electrode based on electrochemical cyclic co-deposition was prepared. The specific surface area of the electrode was increased, and the conductivity and electrocatalytic activity of the electrode surface were improved by AuNPs dispersed uniformly between the ERGO sheets. The electrode has a good linear response range of 1-6000 渭 M ~ (-1) -20 mm ~ (-1), a higher sensitivity of 0.3029 ~ 0.1522 渭 A 渭 M ~ (-1) cm ~ (-2) and a lower detection limit of 0.13 渭 M ~ (-1) N ~ (3 +) ~ (5) for the detection of Listeria monocytogenes (LM) in aquatic products. For the first time, the preparation method of carboxylated graphene / AuNPs thin film immunosensor based on DEP was proposed. DEP assembly can control the location and placement of CGR and AuNPs on the electrode surface. The obtained CGR/AuNPs film is conducive to the stable fixation of a large number of antibodies. The optimized sensor can be linearly detected for 2-2 脳 10 ~ 5 CFU/mL, and the detection limit is 1 CFU / m ~ (-1) L ~ (-1) S / N ~ (3 +). These results provide a new idea for the construction of high performance sensors based on micro-nano structure electrode interface, and also provide technical support for rapid detection of food quality and safety.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TS254.7;O657.1
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本文编号：1967900