【作者】 吴晓玲；

【导师】 胥传来；

【作者基本信息】 江南大学 ， 食品营养与安全， 2014， 博士

【摘要】 本论文以功能性的金、银、碳纳米材料为基础，基于抗原-抗体免疫反应、核酸探针等分子识别体系，可控组装了高产率的纳米材料二聚体、三聚体、核壳结构以及多层膜结构，重点研究了这些纳米组装体的等离子共振、手性吸收以及电子传递等特性及其产生机制，最终构建了超灵敏的生物传感检测新方法，实现了抗生素、藻毒素及环境激素等食品安全重要危害因子的快速、超灵敏的检测分析。首先，将金、银纳米粒子采用配对的抗体、抗原偶联修饰，调节相应的偶联比、偶联反应条件，可控自组装成高产率的金-银纳米粒子二聚体。这种简单的纳米粒子二聚体，由于抗原、抗体生物大分子的相互匹配、链结而形成了特定对映体倾向的“剪刀”状的纳米粒子二聚体，打破了对映体平衡，形成了对映体过剩，最终在可见光区域获得了双峰型、强的等离子手性吸收。其次，基于富含胞嘧啶碱基的核酸序列与银离子的错配等作用，在核酸骨架上可控生长了手性的银纳米粒子。这种银纳米粒子的等离子手性可以通过构建的金属纳米粒子二聚体的“热点”的电磁场增强而放大其手性信号，形成强手性的金、银纳米材料三聚体的组装结构。处于组装体中间的后生长的手性银纳米粒子，由于等离子共振耦合、电磁场增强等效应同时放大了原纳米粒子组装二聚体的等离子手性信号。此外，基于核酸驱动的手性银纳米粒子的生长模式，还可控构建了单分散的金-银核壳型纳米结构，这种核壳结构固有的、大的电磁场增强因子进一步的增强和放大了银壳层的等离子手性吸收，最终成功的获得了强手性的单分散的纳米粒子胶体溶液。再次，基于金-银纳米粒子手性组装体的研究基础，利用纳米粒子组装二聚体的手性与二聚体的浓度梯度变化关系，开发了一种超灵敏的手性传感检测体系，不但成功实施了对双酚A、小肽等小分子量目标物的超灵敏检测，而且还实现了生物蛋白等大分量目标物的超灵敏传感检测，最低检测限分别为0.002ng/mL (8.77×1012M)，0.0008ng/mL(8.04×1013M)和5×1010ng/mL (1.52×1020M)。这种超灵敏的传感检测的成功实现依赖于双峰型的手性光谱、入射光和纳米粒子间的强烈共振耦合及其生物分子的固有手性增强等三重的放大效应。最后，基于碳纳米管的纳米复合材料以及层层组装技术，构建了碳纳米管的纸基多层膜结构，揭示了纸基的碳纳米管的排布以及电子传递情况，建立了一种快速、灵敏的新霉素检测方法，实现了牛奶中新霉素的超灵敏传感检测，最低检测限水平为0.04ng/mL，牛奶样品的添加回收率在93.55—110.44%范围内。更多还原

【Abstract】 High yield of nanoparticle dimers, trimers, core-shell nanostructures, and multilayermembranes have been controllably assembled in this dissertation, based on the functionalgold, silver, carbon nanomaterials as well as the molecular recongnition system ofantigen-antibody immune response and nucleic acid probe. Following the thoroughlyinvestigation of the plasmonic resonance, chiral absorption and electron transfer propertiesand generation mechanisms of the assembled superstructures, ultrasensitive biosensingmethods have been developed in this dissertation, which has successfully realized thesensitive, rapid detections of critical hazard factors of food safety such as antibotics, biotoxins,and environmental hormones.Firstly, gold and silver nanoparticles were modified with pairs of monoclonal antibodyand antigen, respectively. By regulating the corresponding molar ratio and couplingconditions, controllable assemblies of gold-silver nanoparticle dimers were achieved withhigh yield. Due to the specific conformation and matching interaction of bridgingbiomolecules, the nanoparticle dimers tended to display as scissor-like geometry. Theconsistency of preference of specific-enantiomeric sign, broke the enantiomeric equivalenceof the nanoparticle pairs, resulted in the enantiomeric excess, and eventually acquired strong,bisignate chiroplasmonic absorption in the visible part of the circularly dichroism spectra.Secondly, chiral silver nanoparticles have been achieved by controllably growing alongthe scaffold of the nucleic acid, based on the cytosine-rich DNA template and the well-known―metal-base‖mispairing. The chiroplasmonic absorption can be enhanced by the strongelectromagnetic coupling from―hot-spot‖of metal nanoparticle dimers, resulting in theconstruction of strong chiral nanoparticle trimers based on the gold and silver nanomaterials.Meanwhile, the subsequent growing silver nanoparticle has also improved the chiral signal ofthe former assembled dimers, owing to the plasmonic resonance and electromagnetic couplingeffects. Besides, monodispersed gold-silver core shell nanostructures have also been obtained,with the silver grown under the guidance of the DNA template. The intrinsically largeelectromagentic enhancement factor of core-shell nanostructures, has further improved theplasmonic chiral absorption, and ultimately achieved intense chiral nanoparticle colloids.Thirdly, an ultrasensitive chiroplasmonic biosensing method has been developed, takingadvantage of gold-silver chiral heterodimers structures and the chiral signal sensitive responseto the concentration of heterodimers. The developed novel biosensor has not only successfullyrealized the supersensitive detections of analytes with small molecular weight such asBisphenol A of0.002ng/mL (8.77×1012M) and small peptide of0.0008ng/mL (8.04×1013M), but also achieved the detection of biological protein of5×1010ng/mL (1.52×1020M). The surprising ultrasensitivity of this developed method should attribute to thebisignate shape of chiral spectrum, strongly plasmonic coupling of the incident polarized lightwith the nanostructures, and inherent chirality of biomacromolecules.Lastly, paper supported membrane nanostructure with multilayers of carbon nanotubeshave been constructed through layer-by-layer assembly technology. Then a rapid, sensitive detection method for neomycin biosensing has been developed, based on the configuration ofcarbon nanotubes on the paper support and electron transfer principle. The limit of detectionof neomycin was0.04ng/mL, with the recovery ranging from93.55to110.44%in the milk.更多还原