基于（类）石墨烯与聚苯胺及其衍生物的DNA传感器界面

发布时间：2018-06-19 02:36

本文选题：氧化石墨烯 + 二硫化钼　；参考：《青岛科技大学》2015年硕士论文

【摘要】：(类)石墨烯基导电聚合物凭借其良好的导电能力和独特的官能团引起了科研工作者们的广泛兴趣。本论文以(类)石墨烯为支撑材料,在它表面上化学聚合苯胺或其衍生物单体,制备了三种纳米复合材料,并基于所得材料进行了一系列的电化学传感研究。具体工作可以被划分为以下三点：(1)采用氧化石墨烯(GNO)作为支撑材料,制备得到了不同形貌的聚苯胺-氧化石墨烯(PANI-GNO)纳米复合材料,并将它们在DNA传感中的电化学行为进行了比较。由于在聚苯胺(PANI)的成核以及生长过程中,GNO作为一种良好的支撑或模板存在,因此我们成功地得到了石墨烯基的聚苯胺纳米结构。倘若不存在GNO,那么就会得到自由结合的PANI纳米线。此外,冰浴条件下不同的反应时间制备得到的PANI-GNO纳米复合材料的形貌明显不同,其中包括小牛角状(5和12h)、垂直阵列(18h)、纳米尖端(24 h)。也就是说,我们可以通过改变冰浴条件下的反应时间来控制]PANI-GNO纳米复合材料的形貌。而且,实验结果表明基于不同形貌PANI-GNO纳米复合材料构建的DNA电化学传感器,具有不同的ssDNA表面覆盖量以及杂交效率。与其它形貌的PANI-GNO纳米复合材料(5,12和24 h)相比,垂直阵列(18 h)展现出最佳的检测限(2.08×10-16M)。这可以归因于这种纳米复合材料具有更大的比表面积和更多的有效空间,可以为探针DNA(pDNA)的固定以及杂交检测提供最佳的平衡。(2)采用GNO、苯胺(ANI)和氨基苯磺酸(ABSA)单体作为初始材料,通过改变复合材料的制备条件(如成分、单体组成(ANI与ABSA的摩尔比率)、反应时间),从而制备了一系列的纳米复合材料,并将它们用于DNA电化学传感对比。纳米复合材料的自身信号被用于评估复合材料的制备条件对于pDNA固定以及杂交检测的影响。然后,我们发现与其它两个影响因素相比,ANI与ABSA的摩尔比率对于杂交效率的影响更大。同时,我们使用亚甲基蓝(MB)作为外部指示剂进行一系列的平行实验,也得出了同样的结论。此外,我们还对不同摩尔比率制备的磺酸化聚苯胺-氧化石墨烯(SPAN-GNO)纳米复合材料修饰电极的灵敏度进行了相关测定。与其它摩尔比率制备的SPAN-GNO纳米复合材料相比,2：3展现出最大的线性检测范围1.0×10-14～1.0×10-6 M以及最佳的检测限3.06×10-15M。(3)通过简单的超声剥离得到薄层二硫化钼(MoS2),然后在其表面上氧化聚合ANI单体,从而制备得到了聚苯胺-二硫化钼(PANI-MoS2)纳米复合材料。众所周知,导电聚合物,例如PANI,凭借其自身信号可以作为直接传感器,不需要借助任何的标记物或指示剂。而且,MoS2不仅可以作为一个良好的导电骨架为PANI的氧化还原提供较大的电催化活性面积,而且也可以为PANI氧化还原过程中电子交换提供直接路径。因此,与单一的PANI或MoS2相比,PANI与MoS2的复合物展现出较好的电化学性能,并且可以作为一种优秀的候选者用于免标记、直接电化学DNA传感。采用复合材料的自身信号作为检测信号,我们进行了一系列实验考察了合成条件(如成分、MoS2用量、反应时间)对pDNA固定以及杂交检测的影响。结果显示,相比于其它两个合成条件,MoS2用量的影响更大,而这一结论也被使用MB作为外部指示剂的平行实验所证实。秉着高灵敏DNA检测的准则,最后考察了一下MoS2用量与DNA检测灵敏度之间联系。实验数据表明,MoS2用量从0.009g增长到0.072 g过程中,在0.054 g时,CaMV35S基因序列的检测限达到了最佳值。
[Abstract]:(class) graphene based conductive polymers have aroused wide interest of researchers with their good conductivity and unique functional groups. In this paper, three kinds of nanocomposites were prepared by chemically polymerizing aniline or its derivative monomers on the surface of (class) graphene. A series of materials were made based on the obtained materials. The electrochemical sensing study. The specific work can be divided into three points: (1) using GNO as a supporting material, the different morphologies of polyaniline oxide (PANI-GNO) nanocomposites are prepared, and their electrochemical behavior in DNA sensing is compared. The nucleation of polyaniline (PANI) and its nucleation are compared. In the process of growth, GNO as a good support or template exists, so we have successfully obtained the graphene based polyaniline nanostructure. If there is no GNO, then the free binding PANI nanowires will be obtained. In addition, the morphology of the PANI-GNO nanocomposites prepared by different reaction time in the ice bath is not obvious. The same includes the calf angle (5 and 12h), the vertical array (18h) and the nano tip (24 h). In other words, we can control the morphology of the]PANI-GNO nanocomposites by changing the reaction time of the ice bath. Moreover, the experimental results show that the DNA electrochemical sensors based on the different morphology PANI-GNO nanocomposites have no effect. The same ssDNA surface coverage and cross efficiency. Compared with other morphologies, PANI-GNO nanocomposites (5,12 and 24 h), the vertical array (18 h) shows the best detection limit (2.08 * 10-16M). This can be attributed to the larger specific surface area and more effective space for this nanocomposite, which can be fixed to the probe DNA (pDNA). And the best balance of hybridization detection is provided. (2) using GNO, aniline (ANI) and amino benzene sulfonic acid (ABSA) monomers as initial materials, a series of nanocomposites are prepared by changing the preparation conditions of the composites (such as components, monomer composition (molar ratio of ANI and ABSA), reaction time), and they are used for DNA electrochemical sensing. The self signal of the nanocomposite was used to assess the effects of the preparation conditions of the composite on pDNA fixation and hybridization detection. Then, we found that the molar ratio of ANI to ABSA has greater influence on the efficiency of hybridization compared to the other two factors. At the same time, we use methylene blue (MB) as an external indicator. A series of parallel experiments have come to the same conclusion. In addition, we also determine the sensitivity of the sulfonated polyaniline oxide (SPAN-GNO) nanocomposite modified electrode prepared by different molar ratios. Compared with the SPAN-GNO nanocomposites prepared by other molar ratios, the 2:3 exhibits the greatest linearity. The detection range of 1 * 10-14 to 1 * 10-6 M and the best detection limit of 3.06 x 10-15M. (3) are obtained by simple ultrasonic stripping to get thin layer of molybdenum disulfide (MoS2), and then oxidize and polymerized ANI monomer on its surface, thus preparing polyaniline molybdenum disulfide (PANI-MoS2) nanocomposites. It is known that conductive polymers, such as PANI, have been known to rely on them. The self signal can be used as a direct sensor without the use of any marker or indicator. Moreover, MoS2 can not only provide a larger electrocatalytic active area for the oxidation reduction of PANI as a good conductive skeleton, but also provide a direct path for the electrodeposition of the PANI redox process. Compared with MoS2, the complex of PANI and MoS2 shows good electrochemical performance, and can be used as an excellent candidate for non labeling, direct electrochemical DNA sensing. Using the self signal of the composite as the detection signal, we have conducted a series of experiments to investigate the synthesis conditions (such as components, MoS2 dosage, reaction time) to pDNA The effect of immobilization and hybridization detection. The results showed that the effect of MoS2 dosage was greater compared to the other two synthetic conditions, and this conclusion was also confirmed by the parallel experiment of MB as an external indicator. The criterion of high sensitive DNA detection was carried out, and the connection between the dosage of MoS2 and the sensitivity of DNA detection was examined. Experimental data showed that When the dosage of MoS2 was increased from 0.009g to 0.072 g, the detection limit of CaMV35S gene reached the best value at 0.054 G.
【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33;TP212

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