基于功能纳米材料光学传感方法的研究
文献类型：学位论文
| 作者 | 付秀丽 |
| 学位类别 | 博士 |
| 答辩日期 | 2013-05-30 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 陈令新 |
| 关键词 | 纳米材料 比色方法 表面增强拉曼散射 荧光方法 光学传感 |
| 学位专业 | 环境科学 |
| 中文摘要 | 纳米技术的蓬勃发展为纳米材料在分析领域的发展和应用开辟了新的思路，各种具有特殊性质的纳米材料的应用推动了化学和生物传感器的迅速发展。本文利用纳米材料的表面反应特性，将之与靶标的优势相结合，设计适宜的传感界面，通过分子识别过程和光学信号检测机制，发展了多种用于研究重金属离子和生物分子的新型化学和生物传感方法，以期实现对靶标的高选择性、高灵敏性检测。本论文的主要研究内容有： 1、利用氧化石墨烯强颜色猝灭能力，发展了一种新的超灵敏检测肝素的比色传感方法。十六烷基三甲基溴化铵（CTAB）稳定的金纳米棒可以通过静电相互作用很容易地自组装在氧化石墨烯的表面，从而导致金纳米棒的表面等离子体共振（SPR）的吸收降低，颜色也随之由深变浅。以聚阳离子鱼精蛋白作为干扰金纳米棒和氧化石墨烯之间静电相互作用的媒介。鱼精蛋白和氧化石墨烯之间较强的相互作用，阻止了金纳米棒在氧化石墨烯表面的吸附。然而，当溶液中含有肝素时，肝素更易于与鱼精蛋白结合，此时金纳米棒就可以自组装到氧化石墨烯的表面，金纳米棒本身的颜色消失。随着肝素浓度的增加，金纳米棒的颜色逐渐褪去，最后变为无色。金纳米棒自组装的量与肝素的浓度成一定的比例关系，因此，金纳米棒SPR吸收和颜色的变化被用于检测肝素的浓度。在优化的实验条件下，该方法的最低检出限为5 ng/mL，线性范围为0.02–0.28 µg/mL。该方法具有高灵敏、高选择性、简单、快速和可视化的优点，有望用于现场灵敏快速检测微量水平的肝素。 2、发展了一种新的基于金纳米粒子在氧化石墨烯表面自组装的比色法用于高灵敏的检测肝素。聚阳离子鱼精蛋白用于诱导柠檬酸根稳定的金纳米粒子通过静电相互作用在氧化石墨烯表面自组装，从而引起SPR吸收的改变，同时溶液颜色呈现蓝色。由于肝素与鱼精蛋白之间具有很强的亲和力，因此，当溶液中含有肝素时就会干扰金纳米粒子的自组装。随着肝素浓度的增加，自组装的金纳米粒子的量逐渐减少，而溶液的颜色也随之由蓝色变为红色。基于此，我们建立了一种基于金纳米粒子自组装的且颜色“由蓝变红”的比色传感方法用于检测肝素。与常见基于“分散–聚集”（“由红变蓝”）的方法相比，尤其是对于低浓度的待测物，这种从蓝色到红色的颜色的变化更易于肉眼观察。此外，鱼精蛋白和肝素之间较强的相互作用确保了本方法对结构类似物以及各种潜在的生理水平共存物种的抗干扰能力。该方法具有免标记、简单、快速和肉眼可见的特点且可以很容易地通过金纳米粒子的自组装及采用两种聚离子介质来实现。在标准溶液中，该方法对肝素特异性检测的最低检出限为3.0 ng/mL，线性范围为0.06–0.36 µg/mL（R= 0.9936）。此方法被成功的应用于胎牛血清样本中肝素的测定，最低检出限为1.7 ng/mL，线性范围为0–0.8 µg/mL。 3、利用聚阳离子鱼精蛋白、核酸适配体和金纳米粒子来比色检测三磷酸腺苷（ATP）和银离子。聚阳离子鱼精蛋白和带负电荷的核酸适配体通过静电相互作用结合在一起，此时加入金纳米粒子后，金纳米粒子在溶液中呈现良好的分散状态，颜色及SPR吸收也为本来的状态。当有靶标存在时，靶标与核酸适配体发生反应，此时鱼精蛋白就会与金纳米粒子发生反应，导致金纳米粒子发生一定程度的聚集，颜色及SPR吸收光谱也随之发生变化，以此来检测溶液中ATP和银离子的含量。在优化的实验条件下，该方法对APT的最低检测浓度为2 nM，对银离子的最低检测浓度为1 nM。 4、利用抗聚集的4 - 巯基吡啶（4-MPY）功能化银纳米粒子及鱼精蛋白和胰蛋白酶之间的特异性相互作用，发展了一种简单、灵敏的表面增强拉曼散射（SERS）方法用于识别和检测胰蛋白酶。聚阳离子鱼精蛋白不仅作为酶水解的底物，同时由于它能够诱导带负电荷的4-MPY功能化银纳米粒子发生团聚，因此它又作为SERS增强的媒介。胰蛋白酶对鱼精蛋白的水解催化作用降低了溶液中鱼精蛋白的浓度，导致银纳米粒子呈分散状态，于是降低了4-MPY的拉曼强度，进而实现对胰蛋白酶的光学检测。该方法对胰蛋白酶的最低检出限为0.1 ng/mL。利用诱导4 - 巯基吡啶（4-MPY）功能化银纳米粒子发生团聚这一方式显著增强了SERS响应信号。该方法具有宽的线性范围（达5个数量级）和较好的相对标准偏差（2.4%~11.6%）。以胰蛋白酶作为一种模型，这一基于催化水解诱导的纳米粒子稳定性变化的新传感方法可以为超灵敏的SERS测量各种蛋白酶提供一个良好的平台。 5、发展了一种基于金纳米粒子功能化氧化石墨烯复合纳米材料的荧光增强型传感方法用于检测水环境中的铅离子。由于金纳米粒子具有良好的荧光猝灭能力，因此金纳米粒子功能化的石墨烯表现出非常小的背景荧光。但是，当有铅离子存在时，复合纳米材料的荧光得到了恢复和增强。这是因为在硫代硫酸根和2 - 巯基乙醇存在时，铅离子会加速金纳米粒子的溶解速率。基于此，本研究对铅离子进行了选择性的测定。在最佳优化条件下，复合纳米材料的相对荧光强度与铅离子浓度的负对数值在50–1000 nM范围内显示出良好的线性关系（R= 0.9982），检测限为10 nM。该方法对其他常见的共存金属离子具有良好的抗干扰能力。通过对自来水和矿泉水水样品的检测，证明了该方法具有一定的实际应用价值。这一基于铅离子加速溶解石墨烯表面金纳米离子的增强型荧光传感器，为高灵敏和高选择性检测水环境中铅离子提供了新的思路。 |
| 英文摘要 | With the vigorous development of nanotechnology, nanomaterials open a new train of thought for the application in the field of analysis. Owing to the superior properties of nanomaterials, their application promoted the rapid development of chemical and biological sensors. Taking the advantages of surface reaction characteristics as well as the combining with target, design appropriate sensor interface, molecular recognition process and optical signal detection mechanism, we developed a variety of new chemical and biological sensing methods in order to highly selective and sensitive detect the heavy metal ions and biological molecules. The mainly contents are as follows:1. A novel label-free colorimetric strategy was developed for ultrasensitive detection of heparin by using the super color quenching capacity of graphene oxide (GO). Hexadecyltrimethylammonium bromide (CTAB)-stabilized gold nanorods (AuNRs) could easily self-assembly onto the surface of GO through electrostatic interaction, resulting in decrease of the surface plasmon resonance (SPR) absorption and consequent color quenching change of the AuNRs from deep to light. Polycationic protamine was used as a medium for disturbing the electrostatic interaction between AuNRs and GO. The AuNRs were prevented from being adsorbed onto the surface of GO because of the stronger interaction between protamine and GO, showing a native color of the AuNRs. On the contrary, in the presence of heparin, which was more easily to combine with protamine, the AuNRs could self-assembly onto the surface of GO, resulting in the native color disappearing of AuNRs. As the concentration of heparin increased, the color of AuNRs would gradually fade until almost colorless. The amounts of self-assembly AuNRs were proportional to the concentration of heparin, and thereby the changes in the SPR absorption and color had been used to monitor heparin levels. Under optimized conditions, good linearity was obtained in a range of 0.02–0.28 µg/mL (R = 0.9957), and a limit of detection was 5 ng/mL. The simultaneous possession of high sensitivity and selectivity, simplicity, rapidity, and visualization enabled this sensor to be potentially applicable for ultrasensitive and rapid on-site detection toward trace heparin.2. A novel colorimetric method was developed for ultrasensitive detection of heparin based on self-assembly of gold nanoparticles (AuNPs) onto the surface of graphene oxide (GO). Polycationic protamine was used as a medium for inducing the self-assembly of citrate-capped AuNPs on GO through electrostatic interaction, resulting in a shift in the surface plasmon resonance (SPR) absorption of AuNPs and exhibiting a blue color. Addition of polyanionic heparin disturbed the self-assemble of AuNPs due to its strong affinity to protamine. With the concentration of heparin increase, the amounts of self-assembly AuNPs decreased and the color changed from blue to red in solution. Therefore, a “blue-to-red” colorimetric sensing strategy based on self-assembly of AuNPs could be established for heparin detection. Compared with the commonly reported aggregation-based methods (“red-to-blue”), the color change from blue to red was more eye-sensitive, especially in low concentration of target. Moreover, stronger interaction between protamine and heparin led to distinguishing heparin from its analogues as well as various potentially coexistent physiological level species. The strategy was simply achieved by the self-assembly nature of AuNPs and the application of two types of polyionic media, showing label-free, simple, rapid and visual. This method could selectively detect heparin with a detection limit of 3.0 ng/mL in standard aqueous solution and a good linearity was obtained ranging from 0.06–0.36 µg/mL (R = 0.9936). It was successfully applied to determination of heparin in fetal bovine serum samples as low as 1.7 ng/mL with a linear range of 0–0.8 µg/mL.3. We developed a colorimetric method for detection of ATP and silver ions using polycation protamine, aptamers and gold nanoparticles. The polycationic protamine could bind aptamers through electrostatic interaction. Thus, in the presence of AuNPs, the AuNRs were well dispersed in the solution displaying a native color and SPR absorption peak. However, in the presence of target, the protamine was released and combind with AuNPs because of the strong interaction between target and aptamers, which resulted in the aggregation of AuNPs as well as the changes in SPR absorption and color. Under optimized conditions, this method could detect ATP and Ag+ with detection limit of 2 nM and 1 nM, respectively.4. In this work, a simple and sensitive surface-enhanced Raman scattering (SERS) strategy was developed for recognition and detection of trypsin, by using anti-aggregation of 4-mercaptopyridine (4-MPY)–functionalized silver nanoparticles (AgNPs) based on the interaction between protamine and trypsin. The polycationic protamine not only served as a substrate for enzyme hydrolysis but also worked as a medium for SERS enhancement, which could bind negatively charged 4-MPY–functionalized AgNPs and induce their aggregation. The hydrolysis catalyzed with trypsin in sample solution decreased the concentration of free protamine, resulting in the dispersion of AgNPs and thus decreasing the Raman intensity of 4-MPY, by which the trypsin could be sensed optically. A detection level down to 0.1 ng/mL for trypsin was obtained. The induced accumulation of AgNPs modified with Raman reporter 4-MPY largely enhanced the SERS responses. A good linearity was found within the wide range over five orders of magnitude and reasonable relative standard deviations (between 2.4 and 11.6%) were attained. By using trypsin as a model, the new concept can provide an excellent platform for ultrasensitive SERS measurements of various proteases/enzymes which can lead to nanoparticles stability change through catalyzed hydrolysis toward substrate.5. A novel platform for effective “turn-on” fluorescence sensing of lead ions (Pb2+) in aqueous solution was developed based on gold nanoparticles (AuNPs)-functionalized graphene. The AuNPs-functionalized graphene exhibited minimal background fluorescence due to extraordinarily high quenching ability of AuNPs. Interestingly, the AuNPs-functionalized graphene underwent fluorescence restoration as well as significant enhancement upon adding Pb2+, which was attributed to the fact that Pb2+ could accelerate the leaching rate of the AuNPs on graphene surfaces in the presence of both thiosulfate (S2O32–) and 2-mercaptoethanol (2-ME). Consequently, this could be utilized as the basis for selective detection of Pb2+. With the optimum conditions chosen, the relative fluorescence intensity showed good linearity versus logarithm concentration of Pb2+ in the range of 50–1000 nM (R = 0.9982), and a detection limit of 10 nM. High selectivity over common co-existent metal ions was also demonstrated. The practical application had been carried out for determination of Pb2+ in tap water and mineral water samples. The Pb2+-specific “turn-on” fluorescence sensor, based on Pb2+ accelerated leaching of AuNPs on the surface of graphene, provided new opportunities for high sensitive and selective Pb2+ detection in aqueous media. KEY WORDS： Nanomaterials, Colorimetric Detection, Surface Enhance Raman Scatting, Fluorescence Detection, Optical Sensor |
| 学科主题 | 化学 |
| 语种 | 中文 |
| 公开日期 | 2013-08-29 |
| 源URL | [http://ir.yic.ac.cn/handle/133337/6726]  |
| 专题 | 中科院烟台海岸带研究所知识产出_学位论文 |
| 推荐引用方式 GB/T 7714 | 付秀丽. 基于功能纳米材料光学传感方法的研究[D]. 北京. 中国科学院研究生院. 2013. |
入库方式： OAI收割
来源：烟台海岸带研究所
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。