【作者】 李昆；

【导师】 樊春海；

【作者基本信息】 中国科学院研究生院（上海应用物理研究所） ， 无机化学， 2014， 博士

【摘要】 局域表面等离子体激元共振是贵金属纳米材料具有的一种特殊的光学性质。这种光与纳米材料的交互作用会引起纳米材料对光的散射、吸收以及光热效应，给生命分析化学领域的研究带来了新的突破。这种光学性质有两个显著的特点。首先，它所发出的散射光亮度高，而且光学稳定性好，没有闪烁、漂白的现象；其次，局域表面等离子体激元共振频率对纳米材料的尺寸、形貌、组成、电荷以及其所处的介电环境非常敏感。因此，贵金属纳米材料，尤其是金纳米材料，已广泛应用于化学或生物传感、计数、成像与示踪之中。暗场显微镜是可以在单颗粒的水平上观察和研究贵金属纳米颗粒的强力武器，能够进行单颗粒成像，并采集其散射光谱。在本论文中，首先进行了纳米等离子体激元材料的合成、构建与表征，而后分别利用其光学性质两方面的特点，将这种材料应用到了生命分析化学领域两个不同层面的研究之中。具体如下：第一，合成了各种形貌的具有等离子体激元性质的纳米材料，包括各种粒径的球形金纳米颗粒、各种长径比的金纳米棒、三角形的金纳米片、银纳米立方体以及金纳米笼，并对其进行了表征。第二，利用金纳米颗粒的光学性质，并在其表面修饰可以特异性识别可卡因的核酸适配体，得到了能够同时进行指纹成像和分子识别的双功能探针。在暗场显微镜下，获取了清晰的潜指纹图像，甚至能分辨出其中第二、三层次的精细结构。与此同时，通过可卡因诱导金纳米颗粒聚集而引起的散射光从绿到红的颜色变化，实现了对潜指纹中可卡因携带量的半定量检测。第三，提出了一种纳米等离子体激元天线介导的间接策略，利用一种DNA组装构建的核-卫星金纳米结构（大的金纳米颗粒为核，是纳米等离子体激元的天线；小的金纳米颗粒为卫星，是多相催化反应的催化剂），于暗场显微镜下在单颗粒水平上实时地监测了金纳米颗粒催化葡萄糖氧化的反应。获得了关于此多相催化反应的大量细节信息，更深入地了解了金纳米颗粒的催化性质，并充分展示了采用暗场显微术和纳米等离子体激元天线策略来研究多相催化反应过程的广阔前景。通过以上研究，完成了一些纳米等离子体激元结构的构建，并将其应用到了生物检测和纳米催化的研究之中。论文最后提出了对本课题的总结，以及与研究内容相关的展望和对下一步工作的构想。纳米等离子体激元学的相关研究在生命分析化学领域有着巨大发展空间。更多还原

【Abstract】 Local Surface Plasmon Resonance (LSPR) is a unique optical property of coinagemetal nanomaterials. Interactions of light and nanomaterials in nanoscale bring lightabsorption, scattering and even a photothermy effect on metal nanomaterials, whichfacilitate the studies in bioanalytical chemistry field. This unique plasmonic propertyis surprisingly highly sensitive to their size, shape, composition, and charge density aswell as local dielectric environment. In addition to high sensitivity, plasmonicnanostructures provide higher intensity, nonblinking, optical stability and easiness toprepare. In consequence, Au and Ag nanostructures have long been widely utilized fornanoplasmonic chemical and biological sensing, counting, imaging and trackingsystem. By Dark-field microscopy (DFM), single-particle imaging and spectroscopycan be obtained.Firstly, gold nanospheres, gold nanorods, gold nanoprisms, silver nanocubes andgold nanocages were synthesized and characterized.Secondly, we reported a conceptually new nanoplasmonic approach to providehigh-resolution dark-field microscopic (DFM) images of latent fingerprints (LFPs) aswell as the ability to identify cocaine in LFPs with aptamer-bound Au nanoparticles(Au NPs). The level2and level3characteristic details of sebaceous LFPs could beclearly observed. Moreover, by using aptamer-bound Au nanoparticles as imaging andrecognition probes, the cocaine-induced aggregation of Au NPs resulted in a truegreen-to-red color change of the scattered light, providing a quasi-quantative methodto identify cocaine loadings in LFPs.Thirdly, we proposed a nanoplasmonic-antenna mediated indirect strategy formonitoring a catalytic reaction at real time and on single nanoparticle level with darkfield microscopy (DFM), and designed a DNA assembled core-satellites (C/S) Aunanostructure comprising a large Au NP core as a plasmonic antenna and severalsurrounding small Au NPs satellites as heterogeneous catalysts, in which the nanoplasmonic properties and catalytic activities of Au NPs are integrated. Thus, theplasmon band shifts of one single C/S nanostructure throughout the reaction providedan indirect means for monitoring the catalytic reaction. Abundant information of thecatalytic reaction and the catalytic activity of single Au NPs were obtained. This studyexemplifies the power of dark-field microscopy and the concept of plasmonic-antennafor in-depth understanding of different chemical processes in a heterogeneouscatalytic reaction.At last, a summary and prospect was completed. There s plenty of room fornanoplasmonics in the bioanalytical chemistry field.更多还原