半导体纳米材料生物传感器及其光电信号放大的研究

发布时间：2019-05-10 05:15

【摘要】：各类抗原、DNA以及癌细胞的检测对于癌症以及与DNA相关疾病的诊断来说至关重要,并且对于病理研究也提供了一个很好的基础,为此各国的研究学者都把检测生物分子作为一项重要任务。近年来,为了实现生物分子的高灵敏、准确、快速检测,各国的生物学家及医学家对各种检测方法进行改革、创新,有了一些显著的成果。然而,很多边远地区发展中国家无法支付价格昂贵的大型仪器,且无法实现专业技术人员操作。因此,各国的研究学者也专注于构建价格低廉、操作简单、灵敏度高、准确性好的便携式生物传感器。本文的研究集中于电化学发光和光致电两种检测方法,并且合成了具有良好光电性能的CdTe、ZnO和SnO2半导体纳米材料,为了增强其光电效果,将其固载在导电性好、比表面积大的石墨烯、碳纳米管、SiO2、多孔PtRu等纳米材料上,并且利用抗体对抗原的特异性识别,以及DNA分子的特异性性杂交性质,使其构建的传感器具有线性范围宽、选择性好,灵敏度高、稳定性好等优点。另一方面,我们自行设计制作了简便、廉价、便携式的检测池或传感器件,从而实现了低成本、高通量即时检测。三年来主要的研究工作有以下四个方面:(1)利用水热法合成CdTe量子点,然后将其固载到合成的SiO2纳米微球表面,再将CdTe量子点包裹的SiO2标记到二抗上,实现单个抗体的多信号标记,并且合成导电性好的磁性石墨烯作为传感基底,使得组装的夹心式的传感器容易分离洗涤、富集,构建好传感器之后在一个自制的流动注射检测池内实现电致发光信号的检测。该方法对前列腺抗原的检测具有高特异性、易操作、低成本等优点。(2)本文首次通过一种简便的水热法一步合成了ZnO量子点和碳纳米管的复合物,将该复合物用来标记二抗,由于碳纳米管大的比表面积和良好的导电性,可以很大程度地放大电化学发光信号,并且以一种简单地电沉积的方法在电极表面修饰上PtAu合金纳米材料,该纳米材料导电性优越,能够进一步放大电化学发光信号,从而提高灵敏度,该方法实现了对前列腺抗原的特异性和高灵敏检测,并且操作简便。(3)通过简便的超声方法一步合成了空心ZnO和石墨烯的复合物,ZnO本身具有很好地光致电性能,与石墨烯复合后,借助于石墨烯的优越的电子传输能力,光致电信号得到了极大地提高,把SK-BR-3癌细胞借助于适配体的特异性连接作用固定到复合物的表面,使得光致电信号减弱,依据此可以检测癌细胞的数量,并且该传感器是基于一个通过化学腐蚀制得的氧化铟锡电极来构建的,成本低,操作简便。(4)我们基于一个便携的装置设计了一个高灵敏的电化学发光免疫分析方法来检测癌胚抗原(CEA),首先,纳米多孔银被固定到打印工作电极上来捕捉一抗,然后用SnO2量子点负载PtRu合金标记的二抗来组装夹心式传感器,该方法实现了癌胚抗原的高灵敏检测。
[Abstract]:The detection of various antigens, DNA and cancer cells is essential for the diagnosis of cancer and DNA-related diseases, and also provides a good basis for pathological research. Therefore, researchers all over the world regard the detection of biomolecules as an important task. In recent years, in order to achieve high sensitivity, accuracy and rapid detection of biomolecules, biologists and medical scientists in various countries have reformed and innovated various detection methods, and have made some remarkable achievements. However, many remote developing countries are unable to pay for expensive large instruments and are unable to operate by professional and technical personnel. Therefore, researchers from all over the world also focus on building portable biosensors with low price, simple operation, high sensitivity and good accuracy. In this paper, we focus on electrochemiluminescence (ECL) and photoelectron detection (ECL) methods, and synthesize CdTe,ZnO and SnO2 semiconductor nanomaterials with good optical and electrical properties. In order to enhance their photoelectric effect, they are immobilized on good electrical conductivity. The specific surface area of graphene, carbon nanotubes, SiO2, porous PtRu and other nano-materials, and the use of antibody antigen specific recognition, as well as the specific hybridization properties of DNA molecules, the constructed sensor has a wide linear range. Good selectivity, high sensitivity, good stability and other advantages. On the other hand, we design and fabricate a simple, cheap and portable detection cell or sensor device, so as to achieve low cost and high throughput real-time detection. The main research work in the past three years is as follows: (1) CdTe quantum dots were synthesized by hydrothermal method, then immobilized on the surface of synthesized SiO2 nanospheres, and then SiO2 coated by CdTe quantum dots was labeled on the second antibody. The multi-signal marking of a single antibody is realized, and the magnetic graphene with good conductivity is synthesized as the sensing substrate, which makes the assembled sandwich sensor easy to separate, wash and enrich. After the sensor is constructed, the electroluminous signal is detected in a self-made flow injection detection cell. This method has the advantages of high specificity, easy operation and low cost. (2) in this paper, the complex of ZnO quantum dots and carbon nanotubes was synthesized by a simple hydrothermal method for the first time. The composite is used to label the second antibody. Because of the large specific surface area and good conductivity of carbon nanotubes, the electrochemiluminescence signal can be amplified to a great extent. The PtAu alloy nanomaterials were modified on the electrode surface by a simple electrodeposition method. The nanomaterials have excellent conductivity and can further amplify the electrochemiluminescence signal, thus improving the sensitivity. This method has achieved the specificity and high sensitivity of detection of prostate antigen. (3) the hollow ZnO and graphene complexes were synthesized by a simple ultrasonic method. The ZnO itself has good photosensitivity. After compounding with graphene, the photoelectrical signal was greatly improved with the help of graphene's superior electron transport ability. The SK-BR-3 cancer cells were immobilized on the surface of the complex with the aid of aptamer-specific conjugation. The photoinduced electrical signal is weakened, according to which the number of cancer cells can be detected, and the sensor is based on an indium tin oxide electrode prepared by chemical corrosion at a low cost. The operation is simple. (4) based on a portable device, we designed a highly sensitive electrochemiluminescence immunoassay method for the detection of carcinoembryonic antigen (CEA),. First, nano-porous silver was fixed on the printed working electrode to capture the first antibody. Then the sandwich sensor was assembled with the second antibody labeled with PtRu alloy loaded with SnO2 quantum dots, and the highly sensitive detection of carcinoembryonic antigen was realized by this method.
【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1;TP212.3

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