基于光学信号的汞离子、黄曲霉毒素B1及生物标志物的快速检测

发布时间：2018-04-29 23:28

本文选题：纳米材料 + 自组装　；参考：《江南大学》2016年硕士论文

【摘要】：本论文利用功能性核酸分子(适配体)的特异性识别,构建了两种类型的具有独特的表面增强拉曼散射(SERS)和圆二色(CD)光谱学活性的纳米材料组装超结构,并将所构建的纳米超结构作为光学活性传感探针,成功发展了系列高特异性和超灵敏的检测新原理和新方法。具体内容如下:1.构建了一种基于金纳米棒寡聚体的SERS传感器,实现了水溶液中汞离子(Hg~(2+))的检测。基于Hg~(2+)高特异性地诱导胸腺嘧啶-胸腺嘧啶(T-T)碱基配对以及拉曼光谱的灵敏性,实现了环境水中Hg~(2+)的痕量检测,该传感器的LOD可达4.3 pM(0.86 pg/m L),线性范围为5-5000 pM。2.首次构建了一种基于金纳米星为“核”周围分布“卫星状”银纳米粒子的超结构SERS传感探针,成功实现了黄曲霉毒素B1(AFB1)的超灵敏检测。将AFB1适配体修饰在银纳米粒子表面,同时互补链修饰在金纳米星表面,利用碱基互补配对原则形成卫星式超结构组装体,进而增强了SERS信号。当体系中存在目标物AFB1时,适配体优先与AFB1结合,使银纳米粒子从“卫星式”组装超结构中解离下来,从而减弱了SERS信号强度。该传感器对AFB1检测具有高特异性和高灵敏度等优势,LOD值达到0.48pg/m L。在花生奶中的添加回收实验进一步证明了该传感器可以应用于实际样品的检测。3.利用适配体与互补序列的配对原则,将金纳米棒可控组装成二聚体,并用于多巴胺的超灵敏检测。随之在金纳米棒二聚体表面沉积了一层银壳显著地提高了电磁场强度。实验结果证明了银包金纳米棒二聚体具有强烈的表面增强拉曼散射效应,是一种非常理想的拉曼增强基底。利用该体系检测多巴胺,最低检测限(LOD)达到了0.006 pM,线性范围为0.01到10 pM。4.基于自组装策略和适配体特异性识别成功构建了金纳米棒二聚体的高特异性和高灵敏的前列腺表面抗原(PSA)检测方法。通过在二聚体表面沉积银壳层,可提高其等离子手性信号强度。实验结果证明了银包金纳米棒二聚体具有强的等离子手性信号,并成功地应用于PSA检测,LOD值达到了0.076 aM,当PSA浓度在0.1到50 aM间,PSA浓度与等离子手性信号强度之间具有良好的线性关系。该传感器有望作为一种通用的检测平台应用于其它肿瘤标志物的定量探测。
[Abstract]:Based on the specific recognition of functional nucleic acid molecules (aptamers), two types of nanomaterials with unique surface enhanced Raman scattering (SERS) and circular dichroism (CD) spectroscopic activity were constructed. A series of new principles and methods of high specificity and hypersensitivity have been successfully developed by using the nanostructure as an optical active sensor probe. The details are as follows: 1. A SERS sensor based on gold nanorods oligomer was constructed to detect mercury ions in aqueous solution. Based on the high specificity of Hg~(2 to induce thymidine-thymidine T-T base pairing and the sensitivity of Raman spectra, trace detection of Hg~(2 in environmental water was achieved. The LOD of the sensor was 4.3 pM(0.86 pg/m L ~ (-1) and the linear range was 5-5000 pM.2. For the first time, a super-structure SERS sensor probe based on the "satellite" silver nanoparticles around the gold nanoparticles was constructed, and the detection of aflatoxin B _ (1) and AFB _ (1) was successfully achieved. The AFB1 aptamer was modified on the surface of silver nanoparticles and the complementary chain was modified on the surface of gold nanoparticles. The satellite superstructure assembly was formed by the principle of base complementary pairing, which enhanced the SERS signal. When the target AFB1 exists in the system, the aptamer preferentially binds to AFB1, which results in the dissociation of silver nanoparticles from the "satellite" assembled superstructure, which weakens the SERS signal intensity. The sensor has the advantages of high specificity and high sensitivity for AFB1 detection. The addition and recovery experiments in peanut milk further prove that the sensor can be applied to the detection of actual samples. 3. The gold nanorods were assembled into dimer by the matching principle of aptamer and complementary sequence and used for the detection of dopamine. A silver shell was deposited on the surface of the gold nanorod dimer and the electric magnetic field intensity was significantly increased. The experimental results show that the silver coated gold nanorod dimer has strong surface-enhanced Raman scattering effect and is an ideal Raman enhanced substrate. The lowest detection limit of dopamine by this system is 0.006 pm and the linear range is 0. 01 to 10 pM.4. Based on self-assembly strategy and aptamer specific recognition, a highly specific and sensitive method for the detection of prostatic surface antigen (PSAs) of gold nanorods was successfully constructed. The plasma chiral signal intensity can be improved by deposition of silver shell on the surface of dimer. The experimental results show that the silver coated gold nanorod dimer has strong plasma chiral signal. It has been successfully applied to the detection of PSA with a LOD value of 0.076 am. There is a good linear relationship between the concentration of PSA and the intensity of plasma chiral signal when the concentration of PSA is between 0.1 and 50 mm. The sensor is expected to be used as a universal detection platform for quantitative detection of other tumor markers.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TS207.3;O657.3

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