纳米结构金属表面等离子体共振的理论研究

发布时间：2018-04-14 02:20

本文选题：表面等离子体共振 + 贵金属纳米粒子　；参考：《东北石油大学》2015年硕士论文

【摘要】：表面等离子体共振技术(Surface Plasmon Resonance,SPR)是近年来非常热门的新型光学传感技术,它对介质折射率的微小变化极其敏感,具有测量精度高、易实现传感器微型化、样品无需标记和无背景干扰等诸多优点,在生物医学、食品安全检测、石油化学等领域应用前景广阔。SPR传感特性与贵金属的纳米结构有密切联系,材料的微观结构、纳米晶粒尺寸、形状对局域光谱特性有显著影响。本文首先介绍SPR传感技术及金属纳米颗粒的研究现状和发展趋势,然后基于表面等离子体共振传感模型,采用离散偶极近似方法对多种尺寸、形状、结构金属纳米粒子的SPR现象进行仿真。在仿真中,针对不同尺寸的单个球形、棒状、立方体形的纳米粒子以及两个、四个、八个球形纳米粒子不同排列结构,分析其对应的消光光谱,阐明纳米粒子结构对消光光谱的响应规律。研究结果表明,随着贵金属纳米粒子尺寸的增大,消光光谱共振波长发生红移,且共振峰强度增强,纳米粒子的共振波长与粒子尺寸近似呈线性关系。研究还发现,不同形状单个纳米粒子形状越尖锐,灵敏度越高;直线排列结构的球形纳米粒子消光光谱随尺寸变化的规律与单个纳米粒子随尺寸变化的规律相同,但随粒子个数的增加,红移变化量降低;此外,平面排列结构的球形纳米粒子消光光谱有多个共振峰,随粒子尺寸的增大,共振峰均红移,且共振强度均逐渐增强,后一个共振峰总比前一个共振峰的红移变化量大,共振强度增幅亦较大;随着平面排列结构粒子个数的增多,共振强度也有所增强,并且球形纳米粒子立方体结构的消光光谱与平面排列结构的消光光谱变化规律相同。上述研究结果能够为表面等离子体共振传感器的设计和优化提供理论指导。
[Abstract]:Surface Plasmon Resonance technique (SPR) is a new type of optical sensing technology, which is very popular in recent years. It is very sensitive to the tiny change of refractive index of medium, has high measuring precision and is easy to realize the miniaturization of sensors.The sample has many advantages, such as no marking and no background interference. It has a broad application prospect in biomedicine, food safety detection, petroleum chemistry and so on. The sensing properties of SPR are closely related to the nanostructures of precious metals, and the microstructure of materials.The size and shape of nanocrystalline grains have a significant effect on the local spectral properties.In this paper, the research status and development trend of SPR sensing technology and metal nanoparticles are introduced, and then based on the surface plasmon resonance sensing model, discrete dipole approximation method is used to study various dimensions and shapes.The SPR phenomenon of structural metal nanoparticles was simulated.In the simulation, the extinction spectra of single spherical, rod-shaped, cubic nanoparticles and two, four or eight spherical nanoparticles with different arrangement structures are analyzed.The response of the structure of nanoparticles to the extinction spectrum is explained.The results show that with the increase of the size of noble metal nanoparticles, the resonance wavelength of extinction spectrum is red-shifted and the intensity of resonance peak increases. The resonance wavelength of nanoparticles is approximately linearly related to particle size.It was also found that the sharper the shape of the single nanoparticles with different shapes, the higher the sensitivity, the extinction spectrum of the spherical nanoparticles with linear arrangement was the same as that of the single nanoparticles.In addition, there are many resonance peaks in the extinction spectrum of spherical nanoparticles with the increase of particle number, and the resonance peaks shift red with the increase of particle size, and the resonance intensity increases gradually.The total red shift of the latter resonance peak is larger than that of the previous resonance peak, and the increase of the resonance intensity is also larger, and the resonance intensity increases with the increase of the number of planar structured particles.The extinction spectrum of spherical nano-particle cube is the same as that of planar structure.These results can provide theoretical guidance for the design and optimization of surface plasmon resonance sensors.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1;TP212

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