基于碳基纳米材料的可视化生物传感器的构建

发布时间：2019-03-13 12:45

【摘要】：人类目前面临的两大问题:癌症的早期诊断和环境污染问题监控。而两大问题解决的根本在于基层源头。经典方法的局限性无法规模应用于基层实际中。因此,构建低花费、操作简单及灵敏度高的便携式双模生物传感器极为重要。本文自主设计制作了多种荧光及比色纸基微流控生物传感器件。利用原位生长法,在纸芯片表面生长贵金属纳米材料,制备了荧光背景低、比表面积大的纸基基底。围绕家居式的快速简便检测诊断,结合新颖的纳米模拟酶可视化比色检测。成功地将荧光/比色双模生物传感器用于肿瘤细胞内micro RNA小分子、癌胚抗原、多糖肿瘤标志物及环境中重金属离子的高灵敏检测中,为肿瘤疾病早期预警及环境污染检测提供了可靠依据。主要开展了以下四个方面的研究工作:(1)基于Pd/Fe_3O_4@C模拟酶微流控纸基多通道比色免疫传感器的设计与应用。采用原位生长的方法绿色合成比天然酶更稳定与生物相容性好的具有过氧化物酶活性的Pd/Fe_3O_4@C。设计多通道三维纸芯片,通过在纸基底上生长金纳米花进一步放大信号,同时检测多种抗原抗体。该纳米材料模拟酶可广泛应用在生物技术和医学领域。(2)基于石墨烯量子点纸基双模生物传感器用于细胞表面多糖的动态表达。在纸基表面原位生长一层金纳米棒用以降低纸的背景荧光。通过再生长一层多孔银及多枝杂交链反应用于双信号放大,可进一步提高细胞表面多糖检测的灵敏度,构建可用于对细胞表面多糖高灵敏、低成本、快速、可视化检测的多通道生物传感器。(3)基于掺杂碳点的金属增强双比率荧光/裸眼双模生物传感器用于微量Pb2+测定。该生物传感器的检测包括颜色变化的可视化预测和精确的比率型荧光分析。ZnFe2O4@Au-Ag双功能纳米复合物的引入不仅可因其磁性使得生物传感器再生而且可增强荧光强度。氮硫掺杂的碳点(N,S-CDs)具有更高的荧光产率。可用于Pb2+环境监测中。(4)基于掺杂碳点和可重复纸基分析设备的金属增强比率型荧光/可视化双模生物传感器用于多种Micro RNA的检测。在纸上生长银纳米花不仅降低了纸基背景荧光而且还通过金属增强荧光效应增强了掺杂碳点的荧光。通过补充荧光探针,可实现荧光纸的可重复利用。多通道纸基传感器件的设计实现多种Micro RNA的同时检测。该方法可以扩展到其他蛋白质或新的疾病诊断和生物标志物基础研究。
[Abstract]:There are two major problems facing human being: early diagnosis of cancer and monitoring of environmental pollution. And the root of solving the two problems lies in the source of grass-roots. The limitations of classical methods can not be applied to grass-roots practice on a large scale. Therefore, it is very important to construct a portable dual-mode biosensor with low cost, simple operation and high sensitivity. In this paper, a variety of fluorescent and colorimetric paper-based microfluidic biosensors have been designed and fabricated. Precious metal nano-materials were grown on the surface of paper chips by in-situ growth method. The paper-based substrates with low fluorescence background and large specific surface area were prepared. Around the home-style rapid and simple detection and diagnosis, combined with novel nano-mimetic enzyme visual colorimetric detection. The fluorescent / colorimetric bimodal biosensor was successfully applied to the highly sensitive detection of small micro RNA molecules, carcinoembryonic antigens, polysaccharide tumor markers and heavy metal ions in the environment of tumor cells. It provides a reliable basis for early warning of tumor diseases and detection of environmental pollution. The main research work is as follows: (1) Design and application of multi-channel colorimetric immunosensor based on simulated enzyme microfluidization based on Pd/Fe_3O_4@C. Green synthesis of Pd/Fe_3O_4@C. with peroxidase activity by in situ growth method is more stable and biocompatible than natural enzyme. A multi-channel three-dimensional paper chip was designed to amplify the signal and detect various antigens and antibodies by growing gold nanorabra on the paper substrate. The nanomaterials mimicking enzymes can be widely used in biotechnology and medicine. (2) two-mode biosensors based on graphene quantum dot paper are used for the dynamic expression of cell surface polysaccharides. A gold nanorod was in situ grown on the surface of the paper to reduce the background fluorescence of the paper. The sensitivity of cell surface polysaccharide detection can be further improved by the growth of a new layer of porous silver and multi-branch cross chain inversion for double signal amplification, which can be used for high sensitivity, low cost and rapid detection of cell surface polysaccharides. Multi-channel biosensors for visual detection. (3) Metal-enhanced dual-ratio fluorescence / naked-eye bimodal biosensor based on doped carbon points for the determination of trace amounts of Pb2. The detection of the biosensor includes visual prediction of color change and accurate specific fluorescence analysis. The introduction of ZnFe _ 2O _ 4 @ Au-Ag bifunctional nanocomplex can not only make the biosensor regenerate but also enhance the fluorescence intensity because of its magnetic properties. Nitrogen and sulfur doped carbon spots (N, Sal CDs) have a higher fluorescence yield. It can be used in Pb2 environmental monitoring. (4) Metal-enhanced ratio fluorescence / visualization dual-mode biosensor based on doped carbon point and repeatable paper-based analysis equipment is used to detect a variety of Micro RNA. The growth of silver nano-flowers on paper not only reduced the paper-based background fluorescence, but also enhanced the fluorescence of doped carbon spots by metal-enhanced fluorescence effect. The fluorescent paper can be reused by adding fluorescent probe. The design of multi-channel paper-based sensing device realizes the simultaneous detection of multiple Micro RNA. This method can be extended to other proteins or new disease diagnosis and biomarker basic research.
【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.3;TP212

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