基于半导体纳米材料的标记型光电化学免疫传感

发布时间：2018-03-26 18:35

本文选题：光电化学　切入点：免疫传感　出处：《南京大学》2016年硕士论文

【摘要】：光电化学生物传感是将光电化学过程与生物分子识别过程相结合而发展起来的一种新的传感技术。其检测原理是：光照下识别元件和目标分子之间的生物识别作用而产生相应电信号的改变。相比较于传统的光学方法,由于其具有装置简单、价格低廉、易于微型化、背景信号低、灵敏度高等优点,光电化学生物传感受到了越来越多的关注。最近十几年来,各种类型的传感模式相继出现,多种目标分析物如生物标记物、DNA序列、细胞及其他生物分子被成功地检测。本论文采用标记性策略构建了高灵敏的光电化学免疫传感器,主要内容如下：1.基于CdSe@ZnS敏化TiO2NWs/Au复合结构及Ab2@V2+信号放大的光电化学免疫传感对CA1 9-9的高灵敏检测利用水热法制备了Ti02纳米线(TiO2NWs)。将TiO2NWs悬浮液滴涂在ITO电极上,高温烧结后形成一层致密的膜。将Au纳米颗粒沉积到TiO2NWs表面形成TiO2NWs/Au复合结构。利用层层组装方法将CdSe@ZnS核壳量子点修饰于电极表面,形成TiO2NWs/Au/CdSe@ZnS敏化结构,并作为传感电极基底用来固定CA19-9捕获抗体(Abl)。将吡啶分子(V2+)标记在CA19-9信号抗体(Ab2)上形成Ab2@V2+连接物,用作为信号放大元件。由于TiO2NWs/Au/CdSe@ZnS敏化结构优越的光电化学性能和Ab2@V2+连接物显著的信号放大作用,所构建的光电化学免疫传感器显示了对CA19-9的高灵敏检测,同时具有良好的特异性、重复性及稳定性。本工作构建的光电化学平台适用于各种类型的高灵敏光电化学免疫分析法,尤其针对于疾病相关的生物标记物的微量或痕量测定。2.基于CdSeTe@CdS:Mn核壳量子点敏化Ti02及CuS纳米晶标记的增强型光电化学夹心免疫传感首先将Ti02纳米颗粒悬浮液滴涂在ITO电极上,高温烧结后形成一层致密的膜。采用静电吸附方法将CdSeTe三元合金量子点(AQDs)修饰于ITO/TiO2电极上,继而通过连续离子层吸附与反应技术将CdS:Mn量子点沉积于CdSeTe AQDs表面,形成TiO2/CdSeTe@CdS:Mn敏化结构,并作为传感电极光电化学基底用于固定CEA捕获抗体(Ab1)；CEA信号抗体(Ab2)用CuS纳米晶(NCs)标记,形成Ab2-CuS连接物,作为传感器的信号放大元件。由于TiO2/CdSeTe@CdS:Mn敏化结构优越的光电化学性能及Ab2-CuS连接物显著的信号放大作用,所设计的光电化学夹心免疫传感器显示了对目标抗原的高灵敏检测,同时还表现了良好的重现性、特异性及稳定性,为光电化学免疫分析提供了一种新型的构建平台。
[Abstract]:Photochemical biosensor is a new sensing technology which combines photochemical process with biomolecular recognition process. In contrast to traditional optical methods, Because of its advantages of simple device, low price, easy miniaturization, low background signal and high sensitivity, photochemical biological transmission has attracted more and more attention. A variety of target analytes such as biomarkers such as DNA sequences, cells and other biomolecules have been successfully detected. In this paper, a highly sensitive photochemical immunosensor was constructed using labeling strategies. The main contents are as follows: 1.The high sensitivity detection of CA1 9-9 by photochemical immunosensor based on CdSe@ZnS sensitized TiO2NWs/Au composite structure and Ab2@V2 signal amplification. The Ti02 nanowires TiO2NWsN were prepared by hydrothermal method. The TiO2NWs suspension droplet was coated on the ITO electrode. After sintering at high temperature, a dense film was formed. Au nanoparticles were deposited on the surface of TiO2NWs to form TiO2NWs/Au composite structure. CdSe@ZnS core-shell quantum dots were modified on the electrode surface by layer-by-layer assembly method to form TiO2NWs/Au/CdSe@ZnS sensitized structure. It was used as the substrate of the sensing electrode to immobilize the CA19-9 capture antibody, and the pyridine molecule V2 was labeled on the CA19-9 signal antibody (Ab2) to form a Ab2@V2 junction. Because of the superior photochemical properties of TiO2NWs/Au/CdSe@ZnS sensitized structure and the remarkable signal amplification effect of Ab2@V2 connectors, the photochemical immunosensor developed in this paper shows a high sensitivity to CA19-9 detection and has good specificity. Reproducibility and stability. The photochemical platform constructed in this work is suitable for various types of highly sensitive photochemical immunoassay. Especially for the trace or trace determination of disease-related biomarkers. (2) enhanced photoelectrochemical sandwich immunosensors based on CdSeTe@CdS:Mn core-shell quantum dots sensitized Ti02 and CuS nanocrystalline labeling first coated Ti02 nanoparticles suspension droplets on ITO electrodes. A dense film was formed after sintering at high temperature. The CdSeTe ternary alloy quantum dots were modified on the ITO/TiO2 electrode by electrostatic adsorption, and then the CdS:Mn quantum dots were deposited on the surface of CdSeTe AQDs by continuous ion layer adsorption and reaction technique, and the TiO2/CdSeTe@CdS:Mn sensitized structure was formed. It was used as the photochemical substrate of the sensing electrode for immobilization of CEA capture antibody (Ab1) and CEA signal antibody (Ab2) labeled with CuS nanocrystalline (NCs) to form a Ab2-CuS junction. As the signal amplifying element of the sensor, because of the superior photoelectric chemical property of the TiO2/CdSeTe@CdS:Mn sensitized structure and the remarkable signal amplification effect of the Ab2-CuS connector, the photoelectric chemical sandwich immunosensor designed by the sensor shows a high sensitivity to the detection of the target antigen. At the same time, it also shows good reproducibility, specificity and stability, which provides a new construction platform for photochemical immunoassay.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O657.1;TP212

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