Theoretical Research On Nanostructuredmetal Surface Plasmon Resonance

The technology of Surface Plasmon Resonance is an optical sensing technology which is very popular these years. SPR is extremely sensitive to subtle changes of the refractive index, with the advantages of high accuracy, easy to implement sensor miniaturization, on-line measurement, and samples label free and no background interference and so on. Extensive applications are expected to be found in the biomedical, food safety testing, petrochemical and other fields. There is a close contact with the nanostructure SPR sensing characteristic and precious metals, the mirostructure of the material, the nanometer grain size and the shape has a significant effect on the local spectral characteristics.In this paper, the SPR sensor technology and research status and development trend of metal nanoparticles is described. Based on surface Plasmon resonance sensing model, using the theoretical analysis and the software simulation mothod, the simulation of surface Plasmon resonance phenomenon of the metal nanoparticles has various sizes, shape, structures, nanoparticles of different size which include single spherical, rod like, cube shaped, and two, four, eight different structural arrangement of spherical nanoparticles. Systematic analysis of the extinction spectra, the response rules is summarized. Simulation results shows that with the increase of noble metal nanoparticles size, extinction spectrum curve red shift, and the strength of the formant enhancement, the relationship between resonance peak wavelength and the particle size of the nanoparticles are substantially linear; Different shapes of a single nanoparticle resonance extinction spectrum while changing with the particle size is the same, but the change of difference in sensitivity, the more sharp the shape, the higher the sensitivity; Spherical nanoparticles alignment extinction spectrum structure change with particle size rule and single nanopaticles change with particle size the same as the rule, but with the increasing number of linear arrangement of particles, red shift change of lower sensitivity; Extinction spectra of spherical nanoparticles of planar array structure with multiple resonance peak, with the increase of particle size, each resonance peaks are red shifted and resonance intensity are increased, the latter formant redshift fast than the former one, resonance strength is also enhanced with increasing fast, along with the increase in number of plane arrangement of the paticles, the resonance strength has been enhanced; Spherical nanoparticles cube with planar array structure arrangement of the structure of the extinction spectra of the extinction spectra of the change rule is the same. According to the obtained conclusion, it can optimize the structure of the sensor and provides the theory basis for the practical application of surface Plasmon resonance sensor.