基于金纳米颗粒功能化二硫化钼纳米复合材料电化学生物传感器的构建及其应用

发布时间：2018-09-05 17:49

【摘要】：生物传感器涉及多学科交叉,它是当前科学研究中常用的重要检测技术。电化学生物传感器作为其重要分支,由于具有响应快、高灵敏度、高选择性、易操作性、低成本等优点,已广泛应用于临床医学、环境监测、农业分析、食品安全等各个领域。纳米材料由于自身具备优异的导电性、生物相容性、电催化性、大的比表面积等性能,可用于修饰电极构建新型电化学生物传感器,从而有效提高电化学传感器的灵敏度和特异性。本文主要从二硫化钼纳米复合材料的制备及其在电化学生物传感器中的应用角度出发,成功制备了金纳米颗粒功能化二硫化钼(AuNPs@MoS_2)和金纳米颗粒和硫堇共同功能化二硫化钼(AuNP-Thi-MoS_2)纳米复合材料,并在此基础上成功构建了电化学酶生物传感器和电化学免疫传感器。具体包括以下内容:(1)利用AuNPs@MoS_2纳米复合材料能够保持血红蛋白(Hb)的生物活性,而且可以促进Hb的活性中心与电极之间的电子转移的特性,构建了基于AuNPs@MoS_2纳米复合材料的电化学酶生物传感器,研究了Hb的直接电化学行为,并实现了对过氧化氢(H2O2)和一氧化氮(NO)的检测。结果表明,AuNPs@MoS_2纳米复合材料修饰的电极对H2O2和NO具有良好的电催化活性。在10-300μM H2O2和10-1100μM NO范围内,基于MoS_2的电化学传感器的电流峰值与H2O2和NO的浓度呈线性关系,其检测限分别可达到4μM H2O2和5μM NO,而且该传感器还展现了较高的选择性和良好的重现性。(2)利用硫堇(Thi)和MoS_2协同还原作用,采用简单的一步合成法可控制备了AuNPThi-MoS_2纳米复合材料。硫堇不仅具备电活性物质的特性,更重要的是可以作为还原剂与MoS_2共同调控金纳米颗粒的形貌。控制Thi和MoS_2的加入浓度比例,可控制备了球形、三角形、四叶草状、花状的金纳米颗粒功能化MoS_2纳米复合材料(AuNP-Thi-MoS_2)。我们选取了四叶草状的AuNP-Thi-MoS_2纳米复合材料作为样本,并对其进行各种仪器表征分析,如透射电子显微镜、紫外、X射线衍射、X射线光电子能谱等,证实我们成功制备了AuNP-ThiMoS_2纳米复合材料。(3)选取四叶草状的AuNP-Thi-MoS_2纳米复合材料作为电极修饰材料,构建了一种用于检测癌胚抗原(CEA)的免标记电化学免疫传感器。该传感器的Thi峰电流降低值与CEA的浓度在1 pg m L-1-10 ng mL-1范围内成明显的线性关系,其最低检测限可达到0.52 pg m L-1。而且该传感器具有良好的灵敏度、选择性和重现性,并可应用于人类血清实际样本检测。
[Abstract]:Biosensor is one of the most important detection techniques in current scientific research. As an important branch of electrochemical biosensor, electrochemical biosensor has been widely used in clinical medicine, environmental monitoring, agricultural analysis, food safety and other fields because of its advantages of quick response, high sensitivity, high selectivity, easy operation and low cost. Due to their excellent electrical conductivity, biocompatibility, electrocatalysis and large specific surface area, nanomaterials can be used to fabricate novel electrochemical biosensors with modified electrodes. Therefore, the sensitivity and specificity of the electrochemical sensor can be improved effectively. In this paper, the preparation of molybdenum disulfide nanocomposites and its application in electrochemical biosensors are discussed. Gold nanoparticles functional molybdenum disulfide (AuNPs@MoS_2) and gold nanoparticles and thionine co-functionalized molybdenum disulfide (AuNP-Thi-MoS_2) nanocomposites were successfully prepared and electrochemical enzyme biosensor and electrochemical immunosensor were successfully constructed. The main contents are as follows: (1) the bioactivity of hemoglobin (Hb) can be maintained by using AuNPs@MoS_2 nanocomposites, and the electron transfer between the active center of Hb and the electrode can be promoted. The electrochemical enzyme biosensor based on AuNPs@MoS_2 nanocomposites was constructed. The direct electrochemical behavior of Hb was studied and the detection of H2O2 and (NO) was realized. The results show that the electrode modified by AuNPs @ MoSport2 nanocomposite has good electrocatalytic activity for H2O2 and NO. In the range of 10-300 渭 M H2O2 and 10-1100 渭 M NO, the peak current of the electrochemical sensor based on MoS_2 is linearly related to the concentration of H2O2 and NO. The detection limits can reach 4 渭 M H2O2 and 5 渭 M NO, respectively. The sensor also shows high selectivity and good reproducibility. (2) the AuNPThi-MoS_2 nanocomposites can be controlled by a simple one-step synthesis method using the synergistic reduction of thionine (Thi) and MoS_2. Thionine not only has the properties of electroactive substances, but also can be used as reducing agent and MoS_2 to control the morphology of gold nanoparticles. By controlling the concentration ratio of Thi and MoS_2, the spherical, triangular, clover and flower-like gold nanoparticles functionalized MoS_2 nanocomposites (AuNP-Thi-MoS_2) can be controlled. The clover AuNP-Thi-MoS_2 nanocomposites were selected as samples and characterized by various instruments, such as transmission electron microscope (TEM), UV X-ray diffraction (UV) and X-ray photoelectron spectroscopy (XPS). It is confirmed that we have successfully prepared AuNP-ThiMoS_2 nanocomposites. (3) A novel electrochemical immunosensor for the detection of carcinoembryonic antigen (CEA) was constructed by using four-leaf AuNP-Thi-MoS_2 nanocomposites as electrode modified materials. The Thi peak current decrease of the sensor is linearly correlated with the concentration of CEA in the range of 1 pg mL ~ (-1) ng mL-1, and the minimum detection limit can reach 0.52 pg mL ~ (-1). Moreover, the sensor has good sensitivity, selectivity and reproducibility, and can be applied to the detection of human serum samples.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O657.1

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