基于纳米材料构建的新型免疫传感器及其在hCG检测中的应用

发布时间：2018-08-13 12:12

【摘要】：人绒毛膜促性腺激素(h CG)是一种由胎盘绒毛膜囊泡的滋养层细胞分泌的糖蛋白激素,属于肽类激素,由α亚基、β亚基和244中氨基酸组成,分子量为36.7 k Da。hCG存在于人体尿液和血液中。女性在怀孕期间,hCG在体内含量变化与妊娠期的一些疾病有关,比如卵巢癌、绒毛上皮癌等,所以构建一种能够快速方便的检测hCG的方法是非常有意义而且很急迫的。电化学免疫传感器具有很多优点,比如高灵敏度、成本低、易操作、处理步骤简单以及检测迅速等,是一种理想的方法。电极的修饰是影响构建的电化学免疫传感器的电化学响应的关键步骤,同时影响生物分子的固定。由于纳米材料具有比表面积大、生物相容性好、电子传递速率快、较高的催化活性以及较强的吸附能力等诸多优点,是修饰电极的理想材料。本论文利用具有不同形貌和不同结构的纳米材料修饰电极,包括多壁碳纳米管、纳米多孔Pd和纳米金,构建电化学免疫传感器,提高电化学免疫传感器的灵敏度,改善电化学免疫传感器的重现性、稳定性以及特异性,以满足临床上对一些生物分子的检测。1.基于多壁碳纳米管-室温离子液体的纳米复合物和纳米多孔Pd构建电化学免疫传感器对h CG进行检测多壁碳纳米管(MWCNTs)和室温离子液体(RTIL)-1-丁基-3-甲基咪唑六氟磷酸盐(BMIMPF6)组成的复合物膜作为电极的第一层修饰材料,这种复合物材料结合了MWCNTs和RTIL的优点。同时讨论其协同作用机理;其次,通过腐蚀得到的纳米多孔Pd(NP-Pd)作为电极的第二层修饰材料,NP-Pd的结构通过EDS、XRD、SEM、TEM和BET进行表征。由于NP-Pd具有较高的比表面积和优异的导电性,hCG的固定量和电子转移速率都得到很大的提高。在优化的实验条件下,免疫传感器的线性范围为0.05-50 ng m L-1,检测限为3.2 pg mL-1。构建的免疫传感器具有较高的灵敏度、良好的重现性和稳定性。此外,将构建的免疫传感器用于实际样品进行检测,结果令人满意。2.利用纳米多孔Pd做标记构建三明治‖型电化学免疫传感器对hCG进行检测通过腐蚀的方法得到NP-Pd,由于NP-Pd具有优异的导电性、良好的生物相容性以及强的电化学催化活性,利用NP-Pd标记辣根过氧化酶标记的抗体(HRP-Ab2)(NP-Pd-HRP-Ab2)构建三明治‖型电化学免疫传感器。纳米金(GNPs)、普鲁士蓝(PB)和GNPs作为电极修饰基质,不仅用于固定抗体(Ab1),而且对信号放大具有很大的作用。在优化的实验条件下,免疫传感器的线性范围为0.05-200 ng mL-1,检测限为9.2 pg mL-1。构建的免疫传感器具有较高的灵敏度、良好的重现性和稳定性。此外,构建的免疫传感器用于实际样品进行检测,结果令人满意。
[Abstract]:Human chorionic gonadotropin (h CG) is a glycoprotein hormone secreted by trophoblastic cells of placental chorionic vesicles. The molecular weight of 36.7 k Da.hCG is present in human urine and blood. The changes of hCG in women during pregnancy are related to some diseases during pregnancy, such as ovarian cancer and choriocarcinoma, so it is very meaningful and urgent to construct a rapid and convenient method to detect hCG. Electrochemical immunosensor has many advantages, such as high sensitivity, low cost, easy operation, simple processing and rapid detection. Electrode modification is a key step to affect the electrochemical response of the constructed electrochemical immunosensor, as well as the immobilization of biomolecules. Nanomaterials are ideal materials for modified electrodes because of their large specific surface area, good biocompatibility, fast electron transfer rate, high catalytic activity and strong adsorption ability. In this paper, electrochemical immunosensors were constructed by using nano-materials with different morphologies and structures, including multi-walled carbon nanotubes, nano-porous PD and nano-gold, to improve the sensitivity of electrochemical immunosensors. To improve the reproducibility, stability and specificity of electrochemical immunosensors for clinical detection of some biomolecules. Electrochemical immunosensor based on nanocomposites of multi-walled carbon nanotubes and room temperature ionic liquids and nano-porous PD for the detection of hCG (MWCNTs) and room temperature ionic liquids (RTIL) -1- Ding Ji -3-methylimidazolium hexafluorophosphoric acid The composite membrane composed of salt (BMIMPF6) was used as the first layer modification material of the electrode. This composite material combines the advantages of MWCNTs and RTIL. At the same time, the synergistic mechanism of NP-Pd was discussed. Secondly, the structure of nano-porous PD (NP-Pd) as the second layer modified material was characterized by BET and BET. The fixed amount and electron transfer rate of NP-Pd have been greatly improved because of its high specific surface area and excellent conductivity. Under the optimized experimental conditions, the linear range of the immunosensor was 0.05-50 ng mL ~ (-1) and the detection limit was 3.2 PG mL ~ (-1). The constructed immunosensor has high sensitivity, good reproducibility and stability. In addition, the constructed immunosensor was used to detect the actual samples with satisfactory results of. 2. 2. NP-Pd was prepared by using nano-porous PD as marker to construct a sandwich type electrochemical immunosensor for the detection of hCG. NP-Pd was obtained by corrosion method. Because of the excellent conductivity, good biocompatibility and strong electrochemical catalytic activity of NP-Pd, NP-Pd was obtained from the electrochemical immunosensor. A sandwich type electrochemical immunosensor was constructed using NP-Pd labeled horseradish peroxidase labeled antibody (HRP-Ab2) (NP-Pd-HRP-Ab2). Nanocrystalline gold (GNPs), Prussian blue (PB) and GNPs were used as electrode modified matrix not only for immobilization of antibody (Ab1) but also for signal amplification. Under the optimized experimental conditions, the linear range of the immunosensor was 0.05-200 ng mL -1 and the detection limit was 9.2 PG mL -1. The constructed immunosensor has high sensitivity, good reproducibility and stability. In addition, the constructed immunosensor was used to detect the actual samples with satisfactory results.
【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

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