金属纳米结构对光谱响应及折射率灵敏度的影响

推导了任意形状金属纳米结构对复杂环境折射率的局域表面等离子体共振(LSPR)光谱响应的解析解，给出了体折射率和局部折射率灵敏度公式，并进行了详细的理论分析和数值验证。结果表明，金属纳米结构的光谱响应与被分析物厚度呈指数增长关系，并与被分析物的折射率、敏感层厚度、金属纳米结构的材料和形状等因素有关。被分析物折射率越高，光谱响应越大。敏感层越厚，局部折射率灵敏度越差。同时，尖锐的金属纳米结构形状可以获得更大的体折射率灵敏度。对金属纳米结构光谱响应及折射率灵敏度的研究对制作高灵敏度LSPR传感器具有重要的指导意义。

Influence of Metal Nanostructures on Spectral Response and Sensitivitie of Refractive Index

An analytical solution is developed to describe the localized surface plasmon resonance (LSPR) responses to complicated environmental refractive index of metal nanostructures with arbitrary shapes. Both local and bulk refractive index sensitivity equations with their essential influence parameters are also presented. Theoretical analysis and numerical calculation results demonstrate that the peak wavelength of the LSPR spectra for metal nanostructures increases exponentially as the analyte thickness grows, and is greatly dependent on the refractive index of analyte, receptor thickness as well as metal nanostructures shapes and materials. The bigger the refractive index of analyte, the greater the spectra response. Furthermore, a thicker receptor will induce poorer local refractive index sensitivity and a sharper shape will bring on greater bulk refractive index sensitivity. These results can be used as guidelines in fabricating high sensitive LSPR-based biochemical sensors.