电化学信号放大新方法的构建与应用

发布时间：2018-11-13 15:24

【摘要】：电化学生物传感器具有特异性强,灵敏度高,检测仪器简单便携等优点,在分析化学和生物分子学等领域获得广泛研究。随着科学的发展,对电化学生物传感器的灵敏度和物质检测限提出了更高的要求,电化学信号放大技术由此产生。本文主要研究了纳米材料和核酸扩增技术在电化学信号放大技术上的应用,概括如下:第一部分,简单介绍了电化学生物传感器的基本原理和分类,并综述了几种纳米材料和核酸扩增技术在电化学信号放大技术上的具体应用。第二部分,通过一个简单的化学方法合成高质量的三维纳米复合物(铂纳米固定在碳纳米笼上)。PtNPs/CNCs在磷酸缓冲溶液中能高效催化葡萄糖氧化,并呈现出快速的响应时间、宽的线性范围、低的检测限,很好的稳定性,高的灵敏度。该电位下可以有效限制其他物质的氧化。这些优越的催化活性和选择性使得PtNPs/CNCs纳米材料对葡萄糖的直接检测具有广阔的应用空间。第三部分,基于靶诱导邻近杂交与滚环扩增(RCA)相结合构建均相电化学免疫分析法。癌胚抗原的非固定检测(CEA)是通过使用一个标记有电活性指示剂的电中性肽核酸(PNA)探针和带负电荷的铟锡氧化物(ITO)电极来实现。该方法灵敏度高,准确度高,具有令人满意的分析物通用性,使得该方法在检测其他生物标志物中获得潜在应用。第四部分,提出了一种新型邻近杂交调控催化DNA发夹组装策略用于电化学免疫测定,该策略基于原位DNA模板合成Pd纳米粒子作为信号标记。通过引入超级夹心反应增加DNA长度,进一步扩增电化学信号。其对测定血清样品中的CEA也有令人满意的分析性能,并显示出良好的再现性和稳定性。同时,由于抗体对抗原的特异性识别,它表现出优异的特异性。因此,基于DNA模板合成Pd纳米粒子的信号放大方法在临床应用中具有巨大的潜力,也适用于超低水平的生物标志物的定量测定。
[Abstract]:Electrochemical biosensor has been widely studied in analytical chemistry, biomolecular and other fields for its advantages of high specificity, high sensitivity and simple and portable detection instruments. With the development of science, the sensitivity and the detection limit of the electrochemical biosensor are required, and the electrochemical signal amplification technology is produced. In this paper, the applications of nanomaterials and nucleic acid amplification techniques in electrochemical signal amplification are mainly studied. The main results are as follows: in the first part, the basic principle and classification of electrochemical biosensors are briefly introduced. The applications of several nanomaterials and nucleic acid amplification techniques in electrochemical signal amplification were reviewed. In the second part, a simple chemical method is used to synthesize high quality three-dimensional nanocomposites (platinum nanometers are immobilized on carbon nanocages). PtNPs/CNCs can efficiently catalyze the oxidation of glucose in phosphoric acid buffer solution and present a rapid response time. Wide linear range, low detection limit, good stability, high sensitivity. This potential can effectively limit the oxidation of other substances. These excellent catalytic activity and selectivity make the direct detection of glucose by PtNPs/CNCs nanomaterials have a wide application space. In the third part, a homogeneous electrochemical immunoassay was constructed based on the combination of target induced proximity hybridization and rolling loop amplification (RCA). The unfixed detection of carcinoembryonic antigen (CEA) is achieved by using an electroneutral peptide nucleic acid (PNA) probe labeled with an electrically active indicator and a negatively charged indium tin oxide (ITO) electrode. This method has the advantages of high sensitivity, high accuracy and satisfactory generality of analytes, which makes it a potential application in the detection of other biomarkers. In the fourth part, a novel proximity hybrid catalyzed DNA hairpin assembly strategy is proposed for electrochemical immunoassay. The strategy is based on in situ DNA template synthesis of Pd nanoparticles as signal marker. The electrochemical signal was further amplified by introducing super sandwich reaction to increase the length of DNA. It also has satisfactory analytical performance for the determination of CEA in serum samples and shows good reproducibility and stability. At the same time, because of the specific recognition of antigens, it shows excellent specificity. Therefore, the signal amplification method based on DNA template to synthesize Pd nanoparticles has great potential in clinical application, and is also suitable for quantitative determination of ultra-low biomarkers.
【学位授予单位】：江苏师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.1

【相似文献】