金纳米粒子在生化分析中的光学信号传导和放大

发布时间：2018-04-12 15:03

本文选题：金纳米粒子 + 信号传导　；参考：《西南大学》2015年硕士论文

【摘要】：金纳米粒子制备简单,粒径均一可控,化学性质稳定,易于表面功能化,并具有强烈的局域表面等离子体共振(Localized surface plasmon resonance, LSPR)等光学性质,成为目前研究最多的纳米材料之一,已广泛应用于催化、生物医药、分析检测等领域。本硕士学位论文利用金纳米粒子独特的光学性能,通过合适的生物偶联和／或功能化,将其应用于免疫分析、重金属离子检测等生化分析中的信号传导和放大,具体包括以下三部分工作：(1)采用金纳米粒子增强表面等离子体共振成像(surface plasmon resonance imaging, SPRi)的信号,用于灵敏免疫检测小分子真菌毒素。各种真菌毒素的检测对于食品安全具有重要意义。SPRi是一种可同时进行多目标物免疫检测分析的光学成像技术,广泛应用于生物大分子免疫检测和相互作用研究。然而,在免疫法检测小分子真菌毒素时,SPRi的灵敏度有限,不能满足检测的实际需要。本文采用竞争免疫模式,利用金纳米粒子放大SPRi信号,对多种小分子毒素进行了同时检测,实现了高选择性、高灵敏度同时检测黄曲霉毒素B1(Aflatoxin B1, AFBl)、赭曲霉素(Ochratoxin A, OTA)和玉米烯酮(Zearalenone, ZEN)三种典型的真菌毒素,其检测限分别为8、30和15 pg mL-’,动态范围达到3个数量级。(2)采用金纳米粒子及其表面原位引发聚合进行SPRi的连续信号放大,实现在大浓度范围灵敏免疫检测肿瘤标志物。现有的SPRi信号放大方法存在定量关系差、难以在大浓度范围内对目标物进行定量检测。本部分工作采用SPRi在夹心免疫法模式下对肿瘤标志物进行免疫检测,通过引入同时负载抗体蛋白和表面引发原子转移自由基聚合(Surface initiated-atom transfer radical polymerization, SI-ATRP)表面引发剂的金纳米粒子实现SPRi信号的第一次放大；此后,在芯片表面以金纳米粒子上的引发剂为活性位点原位引发ATRP,实现第二次SPRi信号放大。采用该方法对典型的肿瘤标志物甲胎蛋白(a-fetoprotein, AF P)在10%的人血清中进行检测,检测限达到1.0ng mL-1,检测的动态范围达到2个数量级。(3)基于2,2'-联吡啶诱导金纳米粒子聚集的可视化汞离子(Hg2+)检测。重金属离子Hg2+是高毒性污染物,简单可靠的现场检测方法非常重要。本部分工作发展了一种基于2,2'-联吡啶诱导金纳米粒子聚集的可视化Hg2+检测方法：2,2'-联吡啶(2,2'-Bipyridyl, Bipy)能诱导金纳米粒子发生可控的线性聚集,伴随溶液由红到蓝的颜色变化；而Hg2+能在金纳米粒子表面形成Au-Hg合金层,从而有效抑制Bipy引起的金纳米粒子聚集。基于此规律建立的可视化Hg2+检测方法选择性良好,检测动态范围为0.2-2μM,采用简单的可见光分光光度计,其检测限可进一步降低到38 nM。同时,该方法对样品pH值和离子强度不敏感,对实际样品表现出良好的检测可靠性和选择性,具有快速现场检测Hg2+的潜力。
[Abstract]:Gold nanoparticles have many advantages such as simple preparation, uniform and controllable particle size, stable chemical properties, easy surface functionalization, and strong optical properties such as localized surface plasmon resonance (Lspa), so they have become one of the most studied nanomaterials.Has been widely used in catalysis, biomedicine, analytical detection and other fields.Using the unique optical properties of gold nanoparticles, this master thesis applies the gold nanoparticles to signal transduction and amplification in biochemical analysis, such as immunoassay, heavy metal ion detection and so on, through appropriate biological coupling and / or functionalization.It includes the following three parts: 1) the use of gold nanoparticles enhanced surface plasmon resonance imaging (SPR) signal for sensitive immunoassay of small molecular mycotoxins.Detection of various mycotoxins is of great significance for food safety. SPRi is an optical imaging technique which can be used for simultaneous detection and analysis of multi-object immunoassay. It is widely used in biomolecular immunoassay and interaction research.However, the sensitivity of SPRi in detection of small molecular mycotoxins by immunoassay is limited and can not meet the practical needs of detection.In this paper, a competitive immune model was used to amplify the SPRi signal by gold nanoparticles, and a variety of small molecular toxins were simultaneously detected, which achieved high selectivity.The dynamic range is up to 3 orders of magnitude.) Gold nanoparticles and in situ polymerization of gold nanoparticles are used to amplify the continuous signal of SPRi and to detect tumor markers in a wide range of sensitive immunoassay.The existing SPRi signal amplification methods have poor quantitative relationship, so it is difficult to detect the target in a wide range of concentrations.In this part, SPRi was used to detect tumor markers in sandwich immunoassay.The first amplification of SPRi signal was achieved by the introduction of gold nanoparticles loaded with both antibody protein and surface-initiated atom transfer radical polymerization surface initiated-atom transfer radical polymerization (SI-ATRP) surface initiator.On the surface of the chip, the initiator on the gold nanoparticles was used as the active site to initiate the ATRPs in situ to amplify the second SPRi signal.This method was used to detect the typical tumor marker Afetoprotein (AFPin) in 10% of human serum.The detection limit is up to 1.0ng mL-1, and the dynamic range of detection is two orders of magnitude. The detection is based on the visible mercury ion Hg2 based on 2zapyridine-bipyridine induced gold nanoparticles aggregation.Heavy metal ion (Hg2) is a highly toxic pollutant, and a simple and reliable field detection method is very important.In this part of our work, we developed a visual Hg2 method for the detection of gold nanoparticles based on the aggregation of gold nanoparticles induced by 2zapyridine and bipyridine, which can induce the controlled linear aggregation of gold nanoparticles with the color change of solution from red to blue.Hg2 can form Au-Hg alloy layer on the surface of gold nanoparticles, which can effectively inhibit the aggregation of gold nanoparticles induced by Bipy.The visual Hg2 detection method based on this rule has good selectivity, and the detection dynamic range is 0.2-2 渭 M. the detection limit can be further reduced to 38 nm by using a simple visible light spectrophotometer.At the same time, the method is not sensitive to the pH value and ionic strength of the sample, and has good reliability and selectivity for the actual sample detection. It has the potential of rapid field detection of Hg2.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O614.123;TB383.1;O657.3

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