【作者】 王旭东；

【导师】 李敏杰；

【作者基本信息】 吉林大学 ， 高分子化学与物理， 2014， 硕士

【摘要】 由于贵金属纳米材料具有比小分子材料或体相材料更加优越的光电性质，因此自从被发现以来，一直引起科学界的广泛关注。其特殊的性质主要取决于它所具有的局域表面等离子体共振（LSPR）特性。LSPR是指金属纳米材料表面电子，在光的激发下会发生相干振荡，当光的频率与电子振动频率相当时，这种振荡的幅度达到最大，即表面等离子体共振。LSPR性质不仅取决于纳米粒子自身的结构特点如形貌、尺寸、组成等，也受周围介电环境等因素的影响。因此贵金属纳米材料被广泛用于生物传感检测及表面增强谱学等领域。虽然人们在溶液相合成与制备纳米材料的技术中，已经实现对于纳米粒子形态学方面的精细调控，但是溶液相状态的纳米材料对于后续的应用研究始终有着一定的局限性。与此同时，诸如自上而下的构筑方法以及多种非传统的刻蚀技术，如纳米球刻蚀、胶体刻蚀、纳米压印等方法也被逐渐发明和广泛应用。虽然非传统的刻蚀技术已经在一定程度上克服了诸如EBL、FBL等自上而下的构筑方法所固有的高成本、低效率等缺陷，但是其操作过程仍然较为繁琐，且不能大面积构筑金属纳米结构。基于以上原因，本论文利用静电吸附组装的方法，使溶液相的纳米粒子较为有序的组装到氨基硅烷化的基底表面，实现了具有不同粒子间耦合作用的金纳米结构的构筑。该方法操作简单、低成本、在不依赖大型仪器的同时还可以根据实验需要进行大面积的构筑金纳米结构。通过溶液相合成技术调控纳米结构中金纳米粒子的尺寸，通过沉积时间与溶胶离子强度等因素的调节，不仅实现了纳米结构构筑中对于粒子密度及粒子间距的有效调节，也监控了粒子由溶液相逐渐组装到基底表面的行为。通过对纳米结构的加热后处理，可以进一步调节纳米结构的形貌。对于纳米结构折射率传感性质进行系统研究中，我们发现粒子尺寸对于LSPR峰的RIS性质有一定的影响，金纳米结构的灵敏度随着其组成基元粒子的尺寸的增大而升高，但是并不严格的遵循这一规律，而纳米结构中粒子密度及粒子的间距对于其LSPR特征峰的RIS性质并无明显影响。更重要的是，我们发现粒子间的耦合作用对于周围环境折射率有着比LSPR更强的敏感性。虽然在紫外-可见光谱中粒子间耦合作用产生的消光峰半峰宽与LSPR消光峰相比，半峰宽相对较宽，但是也仍然为贵金属纳米材料的制备与构筑及其在生物传感等领域的应用提供了新的方向与思路。更多还原

【Abstract】 Noble metal nanomaterials have attracted great interests since they werediscovered owing to their superior photoelectric properties that are distinct fromanalogous atomic or bulk materials. The special properties are due in large part tolocalized surface plamon resonance (LSPR). Localized surface plasmon resonance iscollective electron oscillations on the surface of conductive nanoparticles that areexcited by appropriate incident light. The LSPR properties depend not only onstructural features of nanoparticles themselves but also on the parameters ofenvironment. It is concluded via previous researches that size, morphology,aggregation, distance of nanoparticles, refractive index and dielectric constant ofenvironment all have an effect on LSPR of nanoparticles. The localized surfaceplasmon extinction would shift in both wavelength and intensity in response to changeof these factors. Thus, metal nanoparticles were widely applied towards surfaceplasmon enhanced spectroscopy, biosensing and a large amount of other fields.Great progresses have been made in controlling of morphology of metalnanomaterials by solution-phase preparation, however solution-phase nanomaterialshave a few inevitable limits in applications. At the same time, a lot of top-down andunconventional fabrication techniques have been invented and widely used, such aselectron beam lithography, focused ion beam lithography, nanosphere lithography,colloid lithography and imprint lithography. Although unconventional lithographytechniques has overcome the high cost and low efficiency in top-down lithographytechniques, they still cannot be used to fabricate nanostructures in a large scale.Herein, we fabricate metal nanostrucutures with different interparticle distancesand different densities of nanoparticles by self-assembly due to static interactionbetween gold nanoparticles and substrates derivatized with aminopropyltrimethoxysilane (APTMS). The sizes of gold nanoparticles can becontrolled with different ratio of reactants. Average inter-particle distance and densityof particles can also be adjusted by deposition time and ionic strength of colloidsolution. Furthermore, Morphology of nanostructures can be influenced by theannealing process at various temperatures. This mehod of fabrication is facile, simpleand of low cost and can be utilized to construct metal nanostructures in a large scale.In studying the refractive index sensing property of above nanostructures, wefound that the RIS property of LSPR extinction peak can be increased with averagesize of nanoparticles and that interparticle distance and density of nanoparticle haveno apparent influence on the RIS properties of LSPR extinction peak. Moreimportantly, refractive index sensitivity can be enhanced by inter-particle couplingeffect remarkably. Although in UV-Vis spectra, the half peak width of the extinctionpeak due to coupling effect is wider than that of the extinction peak due to LSPR, itstill provide crucial guidance and a potential platform for biosensing and otherapplications.更多还原