双极电极电化学发光生物传感器的研究

发布时间：2018-09-06 07:26

【摘要】：直接在微导管或者两端检测池中施加一定的电压,处于该电场中的导体和溶液界面之间即会产生电势差,当电势差达到一定值时就会引发电活性物质在导体两端发生氧化还原反应,这样能在两端发生电化学反应的导体我们称之为双极电极。近年来,将双极电极与电化学发光技术相结合,应用于生命分析和环境监测,已经成为当前的研究热点之一。该方法具有诸多优点,如灵敏度高、成本低廉、装置简单等。目前,双极电极-电化学发光技术(BPE-ECL)己经成功运用于分子筛选、可视化阵列化对细胞、DNA检测等方面。研究微型的、便于携带的BPE-ECL分子识别平台是今后研究重点,本文以双极电极-电化学发光技术为基础,通过合成、电沉积相关纳米材料实现了 ECL信号的增强,构建了几种不同的BPE-ECL检测平台,具体内容如下:(1)基于以ITO作为双极电极的BPE-ECL检测平台检测H202实验以透光性好的ITO导电玻璃制备成双极电极检测平台,但由于ITO在较高的驱动电压下易损坏,影响ITO的导电性和相应的ECL发光强度。实验在ITO表面电沉积Au膜,Au膜的作用在于防止ITO的损坏并增强ITO的导电性,在双极电极的阳极电沉积PtNPs,催化检测物H2O2,放大ECL信号。通过空气等离子体处理ITO和PDMS检测池,发生不可逆键合,构建出BPE-ECL检测平台,创新地使用CdTe@ZnS油性量子点作为发光体,用于检测H202,线性范围为1.0×10-5-4.0×10-9M。最低检测线为5.0×10-10M。(2)基于以铅笔芯作为双极电极的BPE-ECL纸基检测平台以简单易得的铅笔芯作为双极电极,结合纸基,构建出了一种新型的BPE-ECL检测平台,这种检测平台具有成本低廉、可一次性操作、携带方便等优点。发光体系为传统Ru(bpy)32+体系,实验分别研究了铅笔芯的长度和直径对ECL信号的影响,发现长度和直径越大的铅笔芯的ECL强度越大,其原因可由双极电极的机理公式和电极面积解释。为了扩大制备的这种检测平台在生物分析上的应用,类似的,我们在铅笔芯的阴极端电沉积了 PtNPs,发现BPE-ECL检测平台对H2O2有着很好的响应,成功的对与细胞和酶代谢密切相关的H202进行了检测。(3)基于开关控制的BPE-ECL检测平台同时检测CEA合成了 Pd-PtNPs,在不需要刻蚀的ITO检测平台上构建出免疫三明治传感器,制备成一个发光池和多个传感检测池的环形检测平台。开关的使用可以在外部控制反应发生的反应区域和反应时间,每一个单独的开关代表同一类或者不同的反应,可实现操作简单的对不同浓度的CEA抗原浓度进行检测。通过透射电镜对合成的Pd-PtNPs进行了表征,实现ECL信号的增强。实验发现这种结合开关的BPE-ECL检测平台有着很好的稳定性和重复性,成功地对不同浓度的CEA抗原进行了同时检测。
[Abstract]:If a certain voltage is applied directly to the microcatheter or the two detection cells, the potential difference will occur between the conductor in the electric field and the interface of the solution. When the potential difference reaches a certain value, the redox reaction of the electroactive material will occur at the two ends of the conductor, which is called the bipolar electrode. In recent years, the application of bipolar electrode and electrochemiluminescence technology in life analysis and environmental monitoring has become one of the research hotspots. This method has many advantages, such as high sensitivity, low cost, simple device and so on. At present, bipolar electrochemiluminescence (BPE-ECL) technology has been successfully used in molecular screening, visual array detection of cell DNA, and so on. The research of micro and portable BPE-ECL molecular recognition platform is the focus in the future. Based on bipolar electrochemiluminescence (ECL) technology, the enhancement of ECL signal is achieved by synthesis and electrodeposition of related nanomaterials. Several different BPE-ECL detection platforms are constructed. (1) based on the BPE-ECL detection platform with ITO as the bipolar electrode, the H202 test platform is fabricated by using the ITO conductive glass with good light transmittance to make the bipolar electrode detection platform. However, ITO is easily damaged at high driving voltage, which affects the conductivity of ITO and the corresponding luminescence intensity of ECL. The purpose of the experiment is to prevent the damage of ITO and enhance the conductivity of ITO by electrodeposition of Au film on the surface of ITO. The anodic electrodeposition of PtNPs, catalyst H _ 2O _ 2 at bipolar electrode can amplify the ECL signal. The ITO and PDMS detection cells were treated by air plasma, and the BPE-ECL detection platform was constructed. The CdTe@ZnS oil quantum dots were used as luminescent, and the linear range was 1.0 脳 10 ~ (-5) -4.0 脳 10 ~ (-9) M. The minimum detection line is 5.0 脳 10 ~ (-10) m. (2) based on the BPE-ECL paper-based detection platform with lead pen core as bipolar electrode and simple and easy to obtain lead pen core as bipolar electrode, a new type of BPE-ECL detection platform is constructed, which has low cost. One-time operation, easy to carry and so on. The effect of the length and diameter of the lead pen core on the ECL signal is studied experimentally in the traditional Ru (bpy) 32 system. It is found that the larger the length and diameter of the lead pen core is, the greater the ECL intensity of the lead pen core is, and the reason can be explained by the mechanism formula of the bipolar electrode and the electrode area. In order to expand the application of the platform to biological analysis, similarly, we found that the BPE-ECL detection platform is very responsive to H2O2 by electrodeposition of PtNPs, on the lead pen core. H202, which is closely related to cell and enzyme metabolism, was successfully detected. (3) the BPE-ECL detection platform based on switch control simultaneously detected CEA synthesis and constructed an immune sandwich sensor on the ITO detection platform without etching. A ring detection platform for a light emitting cell and a plurality of sensing detection cells is prepared. The use of switches can control the reaction area and reaction time externally. Each single switch represents the same or different reactions. It can be operated simply to detect the concentration of CEA antigen in different concentrations. The synthesized Pd-PtNPs was characterized by transmission electron microscope (TEM) to enhance the ECL signal. It is found that this BPE-ECL detection platform has good stability and repeatability. Different concentrations of CEA antigens have been successfully detected at the same time.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.1;TP212.3

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