基于化学反应调控的有机染料敏化光阳极的光电化学传感

发布时间：2018-06-18 20:03

本文选题：光电化学传感器 + 染料　；参考：《南京邮电大学》2017年硕士论文

【摘要】：光电化学传感器是基于物质的光电转换特性确定待测物浓度的一类检测装置。光电化学检测方法灵敏度高、设备简单、易于微型化,已经成为一种极具应用潜力的分析方法。以DNA、RNA和蛋白质为检测对象的光电化学传感器,激发单元与检测单元相分离,在实际检测过程中可以减弱各种干扰因素,降低背景信号,提高分析检测的灵敏度和选择性,应用前景广泛。对电化学分析法和光电化学分析法进行文献调研,我们注意到:对光电化学传感器研究的重点在于电解液中光电转换传感识别单元的设计,而光阳极通常固定为一些具有光伏效应的半导体材料,例如氧化钛、氧化锌等。以这种方式构筑的光电化学传感体系在工作状态下,存在严重的界面阻力,从而对整个光电转换效率产生影响,特别是传感检测选择性主要依赖于免疫反应,导致了光电化学生物传感应用受到极大限制。本论文针对此问题,创新性的发展基于光电化学检测技术,利用半导体材料的光电特性产生光生电子空穴对,从而形成光诱导电荷转移的方式实现对光电流进行检测,可以更高选择性和灵敏地检测与该电流相关的生化反应中待测物的浓度。主要研究内容分为以下三个方面:第一,基于染料敏化光电化学太阳能电池的原理,利用具有推-拉电子效应的染料分子在与含巯基化合物反应前后光吸收特性差异造成的光电流变化作为输出检测信号,从而实现对半胱氨酸的传感检测。实验证明,本实验整个过程中不再局限于电极界面过程,能在多种复杂环境中实现特定生物分子如半胱氨酸等含巯基的生物大分子的高灵敏、选择性、定量检测,应用前景巨大。第二,将光电化学传感器与DNA生物传感器相互结合,通过空间限制构造PEC生物传感器实现对mi-RNA的检测。利用ITO/TiO_2/Au为基底,构建稳定基底。将光电化学测试与DNA生物传感器结合起来,同时Au纳米颗粒与P-DNA的连接,起到对信号的放大作用,实验结果得到mi-RNA的检测限为0.12 fM。第三,通过简单水热法制备出的石墨烯/二硫化钼的光阳极复合材料,最大创新点在于充分地利用二硫化钼与石墨烯层状结构,石墨烯基复合材料具有制备简便,结构新颖、稳定,比电容值高等优点。而石墨烯具有超高表面积和导电率,应用于光电化学传感器的光阳极中,为进一步拓展应用提供了基础。总体而言,我们分别对光阳极、电极基底材料、检测对象三个方面进行了初步分析和研究,较深入的对课题设计思想进行验证,初步研究结果表明,我们对光阳极改造的光电化学传感器构筑方法具有创新性和可行性,为此后进行相关研究奠定理论和实践基础。
[Abstract]:Photoelectric chemical sensor is a kind of measuring device which is based on the photoelectric conversion characteristics of matter to determine the concentration of the object to be measured. Photoelectric chemical detection method with high sensitivity, simple equipment and easy miniaturization has become a very potential analytical method. The photochemical sensor with DNA RNA and protein as the detection object, the excitation unit is separated from the detection unit, which can attenuate all kinds of interference factors, reduce the background signal, and improve the sensitivity and selectivity of analysis and detection. The application prospect is wide. Through the literature research on electrochemical analysis and photochemical analysis, we noticed that the focus of the research on photoelectrochemical sensor is the design of photoelectric conversion sensor identification unit in electrolyte. Photoanodes are usually fixed as photovoltaic semiconductor materials, such as titanium oxide, zinc oxide and so on. The photoelectric chemical sensing system constructed in this way has serious interfacial resistance in the working state, which has an impact on the whole photoelectric conversion efficiency, especially the selectivity of the sensing detection mainly depends on the immune response. As a result, the application of photochemical biosensor is greatly restricted. Aiming at this problem, the innovative development of this paper is based on photochemical detection technology, using the photoelectric properties of semiconductor materials to generate photogenerated electron hole pairs, thus the photoinduced charge transfer method is formed to detect photocurrent. It is more selective and sensitive to detect the concentration of the substance to be tested in the biochemical reaction associated with the current. The main research contents are as follows: first, based on the principle of dye sensitized photochemical solar cells, The photocurrent changes caused by the difference of photoabsorption characteristics of dye molecules with push-pull electron effect before and after reaction with sulfhydryl compounds are used as the output detection signals to realize the sensing detection of cysteine. The experiments show that the whole process is no longer confined to the electrode interface process, and it can be used to detect specific biomolecules such as cysteine, in high sensitivity, selectivity and quantification in many complex environments. The application prospect is great. Secondly, PEC biosensor is constructed to detect mi-RNA by combining photochemical sensor with DNA biosensor. The stable substrate is constructed by using ITO / TiO- 2 / au as the substrate. The combination of photochemical test and DNA biosensor and the connection of au nanoparticles with P-DNA can amplify the signal. The detection limit of mi-RNA is 0.12 fM. Third, the photoanode composites of graphene / molybdenum disulfide prepared by simple hydrothermal method have the greatest innovation in making full use of the layered structure of molybdenum disulfide and graphene. Stable, higher than the value of capacitance and other advantages. Graphene has high surface area and conductivity and is used in photoanode of photochemical sensor, which provides a basis for further development of application. In general, we have carried on the preliminary analysis and the research to the photoanode, the electrode substrate material, the inspection object separately, has carried on the confirmation to the topic design idea in depth, the preliminary research result indicated, We are innovative and feasible for the construction of photoanode photochemical sensor, which will lay a theoretical and practical foundation for the related research in the future.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212.2

【参考文献】