金属手性纳米结构的制备及其圆二色性研究

发布时间：2018-01-04 18:21

本文关键词：金属手性纳米结构的制备及其圆二色性研究　出处：《陕西师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：表面等离激元增强的圆二色(Circular Dichroism, CD)光谱作为手性分子微量检测的重要分析手段,在生物医学诊断和病原体探测等方面具有巨大的应用潜力。完善CD产生的物理机制和制备高灵敏度CD探测衬底是该领域的研究重点。金属手性纳米材料是目前公认的高灵敏度CD探测衬底之一,同时,这种结构与光之间的相互作用也使其具有很强的CD效应。金属手性纳米结构的CD效应强烈依赖于其结构参数,这种特性有助于我们研究CD产生的物理机制。本论文以二维胶体晶体为模版用倾斜角沉积的方法制备了L形金属手性纳米结构,并用有限元方法模拟了实验结果,研究了结构参数变化对结构圆二色性的影响。具体内容及结果如下：以二维有序聚苯乙烯微球阵列为模板,采用倾斜角沉积技术制备了不同结构参数的L形手性金属纳米结构,研究了结构参数对其圆二色性的影响。结果表明：倾斜角沉积技术和自组装技术的结合能够制备出形貌可控、结构稳定的金属手性纳米材料；随L形结构两臂之间厚度差和聚苯乙烯微球直径的增大,结构的圆二色性增强且谱线发生红移,实现了在可见和近红外区域对结构圆二色性的调节。这些结果为制备高灵敏度CD探测衬底奠定了一定的基础。运用有限元方法研究了L形金属手性纳米结构的光学特性,并计算了该结构在不同结构参数下的圆二色光谱。结果表明：模拟与实验所得的谱线规律一致；左旋和右旋结构的圆二色光谱对称分布；L形两臂厚度差变大增加了结构的不对称性,结构的圆二色性增强；倾斜角沉积的自阴影效应导致第二层Ag膜倾斜生长,其表面的电子共振长度增加,结构的圆二色光谱红移。这些研究结果有助于进一步理解CD产生的物理机制。
[Abstract]:The circular circular dichroism (CDS) spectra enhanced by surface isoexcitators are used as an important analytical tool for microdetection of chiral molecules. It has great application potential in biomedical diagnosis and pathogen detection. Improving the physical mechanism of CD production and preparing high sensitive CD detection substrates are the key points in this field. Metal chiral nanomaterials are important. Previously recognized as one of the highly sensitive CD substrates. At the same time, the interaction between the structure and light makes it have a strong CD effect. The CD effect of metal chiral nanostructures is strongly dependent on its structural parameters. This characteristic is helpful for us to study the physical mechanism of CD production. In this thesis, L-shaped metal chiral nanostructures were prepared by oblique angle deposition using two-dimensional colloidal crystal as template. The experimental results are simulated by finite element method, and the effect of structural parameters on circular dichroism is studied. The results are as follows: a two-dimensional ordered polystyrene microsphere array is used as a template. L-shape chiral metal nanostructures with different structural parameters were prepared by inclined angle deposition. The effect of structural parameters on circular dichroism was studied. The results show that the combination of inclined angle deposition and self-assembly technology can produce metal chiral nanomaterials with controllable morphology and stable structure. With the increase of the thickness difference between the two arms of L-shaped structure and the diameter of polystyrene microspheres, the circular dichroism of the structure increases and the spectral lines shift red. The adjustment of circular dichroism in visible and near infrared region is realized. These results lay a foundation for the preparation of high sensitivity CD detection substrates. The chiral structure of L-shaped metal has been studied by finite element method. Optical properties. The circular dichroism spectra of the structure under different structural parameters are calculated. Symmetrical distribution of circular dichroism spectra of left-handed and right-handed structures; The thickness difference of L-shaped arms increases the asymmetry of the structure and the circular dichroism of the structure. The self-shading effect of inclined angle deposition results in the inclined growth of the second Ag film and the increase of the electron resonance length on the surface. These results are helpful to further understand the physical mechanism of CD production.
【学位授予单位】：陕西师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1

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