基于MOFs与导电剂组成的纳米复合材料在电化学传感器上的应用研究

发布时间：2018-05-25 13:18

  本文选题：金属有机框架材料 + 导电剂　； 参考：《郑州大学》2017年博士论文

【摘要】：金属有机框架材料(Metal-organic frameworks)是由无机金属中心与有机配体组成。MOFs具有比表面积大、孔径可调、孔容适中和孔隙率高等优势,适合作电化学传感器增敏剂。然而,多数MOFs由于配位键的可逆本性导致稳定性差;许多合成的MOFs属于微米级材料,致使MOFs和传感器表面结合不牢;大部分MOFs的导电性差。MOFs的固有缺陷限制了其在传感器上的广泛应用。为解决上述问题,本文合成了稳定性好的纳米级MOFs材料;在构筑传感器时,引入了导电剂XC-72、Mo S2和多壁碳纳米管(MWCNT),与MOFs组合在一起,制备的MOFs/导电剂复合材料具有大的比表面积、好的电子传递性能和强的吸附能力。本文基于复合材料构筑的高灵敏和高选择性的传感器,有利于增加目标分析物的吸附位点,可以用来检测三聚氰胺(Mel)、氯霉素(CAP)、抗坏血酸(AA)、多巴胺(DA)和尿酸(UA);通过引入分子印迹技术(MIP),制备的MIP电化学传感器可以提高槲皮素(Qu)和没食子酸(GA)的选择性。基于MOFs/导电剂复合材料构筑的传感器具有价格便宜、操作简单、适中的线性浓度范围和低的检测限等优势;构筑的传感器同时具有高的重现性、稳定性、灵敏性和选择性;传感器应用在实际样品中目标分子的检测,具有好的回收率。此外,针对不同传感器检测不同的目标分析物,提出相关机理也是本文的重点研究对象。论文的主要具体工作如下:(1)基于MIL-53/XC-72纳米复合材料修饰的玻碳电极,制备高灵敏和高选择性的传感器,用来检测Mel。利用水热合成方法制备MIL-53,然后与XC-72掺杂在一起,制备了MIL-53/XC-72纳米复合材料。MIL-53、XC-72和MIL-53/XC-72材料和制备的传感器分别用物理方法和电化学方法进行表征。MIL-53/XC-72-Nafion/GCE传感器具有高灵敏性和高选择性,是MIL-53高的比表面积和XC-72好的导电性协同作用、以及Mel和MIL-53间氢键共同作用的结果。在优化条件下,该传感器在0.7 V电位和0.1 M HCl溶液中,对Mel具有好的电化学响应。Mel的线性浓度范围为0.04-10μM,线性回归系数为0.998,检测限为0.005μM。而且,该传感器具有优异的重现性、稳定性和选择性。将其用在牛奶样品Mel的检测中,具有好的回收率。(2)基于MIL-101(Cr)/XC-72修饰的玻碳电极构筑的传感器,用来检测CAP。MIL-101(Cr)、XC-72和MIL-101(Cr)/XC-72用傅里叶变换红外光谱(FTIR)、X射线粉末衍射仪(XRD)、比表面分析仪(BET)和扫描透射电镜(SEM)方法来表征。电化学传感器由三种材料构筑而成,电化学性能用循环伏安法(CV)和差示脉冲溶出伏安法(DPV)详细考察。与在裸电极、MIL-101(Cr)/GCE和XC-72/GCE传感器相比,CAP在MIL-101(Cr)/XC-72/GCE传感器上(电解液为磷酸缓冲溶液,PBS)具有一对好的氧化还原峰。详细考察了MIL-101(Cr)与XC-72的配比、富集时间、扫描速率和p H值等影响因素。在优化条件下,传感器对CAP有好的电化学响应。CAP的线性浓度范围为0.01-20μM(R2=0.985),最低检测限为0.0015μM(S/N=3)。而且,MIL-101(Cr)/XC-72/GCE传感器成功用来检测实际样品,取得了令人满意的回收率。(3)UIO-66-NO_2/XC-72纳米复合物是由水热合成的UIO-66-NO_2与XC-72掺杂组成的。材料的官能团、结构、织构性能和形貌分别由FTIR、XRD、BET、SEM和TEM手段进行系统表征。UIO-66-NO_2/XC-72修饰的玻碳电极传感器成功地用来同时检测AA、DA和UA。由于UIO-66-NO_2具有大的比表面,XC-72具有好的导电性,加上MOFs和目标分析物间的氢键作用,制备的UIO-66-NO_2/XC-72/GCE传感器在优化条件下,对AA、DA和UA具有好的电化学响应。AA、DA和UA的检测范围分别为0.2-3.5μM、0.03-2.0μM和0.75-22μM,检测限分别为0.12μM、0.005μM和0.03μM。而且,本实验中的传感器具有高的重现性和稳定性;该传感器成功地用来检测盐酸注射液中DA的含量,和人体中UA的含量。(4)制备了一种基于MIL-101(Cr)/Mo S2纳米复合材料修饰的玻碳电极,随后在Qu和吡咯存在条件下进行电聚合的传感器。物理表征和电化学表征手段分别用来考察材料的特性和传感器的导电性。采用DPV法检测Qu的含量。详细考察了吡咯的体积、电聚合圈数、电解液的p H值、富集时间等影响因素。在优化条件下,槲皮素在MIP/MIL-101(Cr)/Mo S2/GCE传感器上有两个线性浓度范围,分别是0.1-10.5μM和10.5-700μM,检测限为0.02μM(S/N=3)。而且,该传感器具有好的重现性、稳定性和选择性,并成功地应用在蜂蜜样品中Qu含量的测定。(5)采用MIP技术制备了高灵敏和高选择性的没食子酸传感器。MIP/Fe-MIL-88/MWCNT/GCE传感器首先由Fe-MIL-88/MWCNT复合材料修饰玻碳电极,接着在GA和吡咯存在条件下,电聚合制备而成的。Fe-MIL-88、MWCNT和Fe-MIL-88/MWCNT材料用FTIR、XRD、BET和TEM等方法用来表征,制备的电化学传感器用电化学阻抗(EIS)来表征。采用DPV方法检测GA时,利用K3[Fe(CN)6]/K4[Fe(CN)6]作为电活性探针间接测定GA含量。在优化条件下,GA在该分子印迹传感器上的电流响应与其浓度呈较好的线性关系。检测范围为0.05-24μM(R2=0.998),检测限为0.022μM(S/N=3)。该分子印迹传感器具好的重现性、稳定性和选择性,将其应用在橙汁、绿茶和红茶的GA检测中,实际样品的RSD范围为3.8%-4.3%(n=3),回收率为97.2%-98.9%。
[Abstract]:Metal organic frame material (Metal-organic frameworks) is composed of inorganic metal center and organic ligand, which has the advantages of large specific surface area, adjustable pore size, moderate pore volume and high porosity. It is suitable for electrochemical sensor sensitizer. However, most MOFs has poor stability due to the reversible nature of coordination bonds; many synthetic MOFs genera. In micron grade materials, the surface of MOFs and sensor is unbound, and the inherent defects of most MOFs's poor conductive.MOFs restrict its wide application on the sensor. In order to solve the above problems, this paper has synthesized a good stable nano scale MOFs material. In the construction of sensors, the conductive agent XC-72, Mo S2, and multi walled carbon nanotubes (MWC) were introduced. NT), with the combination of MOFs, the prepared MOFs/ conductive composite has large specific surface area, good electron transfer performance and strong adsorption capacity. The highly sensitive and highly selective sensors based on composite materials are beneficial to increase the adsorption sites of target analytes and can be used for the detection of melamine (Mel), chloramphenicol (CAP). Ascorbic acid (AA), dopamine (DA) and uric acid (UA); by introducing molecular imprinting technology (MIP), the preparation of MIP electrochemical sensors can improve the selectivity of quercetin (Qu) and gallic acid (GA). Sensing devices based on MOFs/ conductive composite materials are cheap, easy to operate, moderate linear concentration range and low detection limit. The sensor has high reproducibility, stability, sensitivity and selectivity at the same time; the sensor has a good recovery rate for the detection of the target molecules in the actual sample. In addition, the relevant mechanism is also the key object of this paper to detect the different target analytes for different sensors. The following are as follows: (1) a highly sensitive and highly selective sensor based on MIL-53/XC-72 nano composite modified glassy carbon electrode was prepared to detect Mel. using hydrothermal synthesis to prepare MIL-53, and then doped with XC-72 to prepare the MIL-53/XC-72 nanocomposite.MIL-53, XC-72 and MIL-53/XC-72 materials and the prepared sensors, respectively. The.MIL-53/XC-72-Nafion/GCE sensor characterized by physical method and electrochemical method has high sensitivity and high selectivity. It is a synergistic effect of high specific surface area of MIL-53 and good conductivity of XC-72, as well as the interaction of hydrogen bonds between Mel and MIL-53. Under optimal conditions, the sensor has a 0.7 V potential and a 0.1 M HCl solution to Mel. The linear concentration range of.Mel with good electrochemical response is 0.04-10 M, the linear regression coefficient is 0.998, the detection limit is 0.005 M., and the sensor has excellent reproducibility, stability and selectivity. It has good recovery rate in the detection of Mel in milk samples. (2) construction based on MIL-101 (Cr) /XC-72 modified glassy carbon electrode The sensor is used to detect CAP.MIL-101 (Cr), XC-72 and MIL-101 (Cr) /XC-72 with Fu Liye transform infrared spectroscopy (FTIR), X ray powder diffractometer (XRD), surface analyzer (BET) and scanning transmission electron microscopy (SEM). Electrochemical sensors are constructed from three materials, and the electrochemical properties are dissolved by cyclic voltammetry (CV) and differential pulse. The volt ampere method (DPV) is detailed. Compared with the bare electrodes, MIL-101 (Cr) /GCE and XC-72/GCE sensors, CAP has a pair of good redox peaks on the MIL-101 (Cr) /XC-72/GCE sensor (the electrolyte is phosphoric acid buffer solution, PBS). Under conditions, the linear concentration range of the sensor with good electrochemical response to CAP.CAP is 0.01-20 mu M (R2=0.985), and the minimum detection limit is 0.0015 mu M (S/N=3). Moreover, MIL-101 (Cr) /XC-72/GCE sensor has been successfully used to detect the actual samples and obtained satisfactory recovery. (3) the UIO-66-NO_2/XC-72 nanocomposite is a hydrothermal synthesis of UIO-66-N. O_2 and XC-72 doping. The functional group, structure, texture, texture, and morphology of the materials are characterized by FTIR, XRD, BET, SEM, and TEM, respectively. The.UIO-66-NO_2/XC-72 modified glassy carbon electrode sensor is successfully used to detect AA, DA and UA. because of the large specific surface of the UIO-66-NO_2. The UIO-66-NO_2/XC-72/GCE sensor has good electrochemical response to AA, DA and UA, and the detection range of DA and UA is 0.2-3.5 u M, 0.03-2.0 um M and 0.75-22 micron, respectively. The detection limits are 0.12 micron, 0.005 Mu and 0.03 micron respectively, and the sensors in this experiment have high reproducibility. The sensor was successfully used to detect the content of DA in hydrochloric acid injection and the content of UA in human body. (4) a kind of glassy carbon electrode modified based on MIL-101 (Cr) /Mo S2 nanocomposites was prepared, and the sensor of electropolymerization under the presence of Qu and pyrrole. Physical characterization and electrochemical characterization were used to investigate respectively. The properties of the material and the conductivity of the sensor. The content of Qu was detected by DPV. The volume of pyrrole, the number of electropolymerization, the P H value of the electrolyte, the concentration time and other factors were investigated in detail. Under the optimum conditions, quercetin had two linear concentration ranges on the MIP/MIL-101 (Cr) /Mo S2/GCE sensor, which were 0.1-10.5 micron M and 10.5-700 micron, respectively. The measurement limit is 0.02 M (S/N=3). Moreover, the sensor has good reproducibility, stability and selectivity, and has been successfully applied to the determination of Qu content in honey samples. (5) the high sensitive and highly selective.MIP/Fe-MIL-88/MWCNT/GCE sensor of gallic acid sensor was prepared by MIP technology, and the glassy carbon was first modified by Fe-MIL-88/MWCNT composite. The electrodes, followed by the presence of GA and pyrrole, are used to characterize the.Fe-MIL-88, MWCNT, and Fe-MIL-88/MWCNT materials prepared by electropolymerization with FTIR, XRD, BET, and TEM. The electrochemical sensors prepared are characterized by electrochemical impedance (EIS). The DPV method is used to detect the GA as an indirect measurement of the electroactive probe. GA content. Under optimal conditions, the current response of GA on the molecularly imprinted sensor has a good linear relationship with its concentration. The detection range is 0.05-24 mu M (R2=0.998), and the detection limit is 0.022 mu M (S/N=3). The molecular imprinting sensor has good reproducibility, stability and selectivity, and applies it to the GA detection of orange juice, green tea and black tea. The RSD range of the sample is 3.8%-4.3% (n=3) and the recovery is 97.2%-98.9%..
【学位授予单位】：郑州大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O657.1
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本文编号：1933258