Research On Substrate Of Surface Plasmon Resonance Sensor Based On Dielectric Loaded

The technology of Surface Plasmon Resonance has wide prospect in food safety testing,environmental detection,clinical diagnosis,etc.as a result of its unique advantages of high sensitivity,label-free,non-loss detection.With in-depth study of SPR sensing technology in different field,the use of metal nanoparticles or nanoparticles array of local surface plasmon resonance sensing technology,become an important direction to detect the application of SPR sensor.Due to the problem of strong light absorption in metals,the substrate of surface plasmon resonance sensor based on dielectric loaded array is presented.The resonance coupling effect and local electric field enhancement of dielectric silicon loaded array are stronger,and corresponding response curve of reflectance spectrum is more acute,by regulating the substrate structure parameters,compared with metallic silver loaded array.Numerical simulation shows that due to media particles without joule heat loss,the sensitivity of the SPR sensor can be improved by reasonable regulation of the structural parameters of the particle array.The resonance enhanced properties of periodic nanoparticle arrays are studied by using electromagnetic field theory and FDTD method.To analyze the scattering characteristic of single nanoparticle,which indicates that the scattering resonance of dielectric brings about local electric field enhancement.It was similar to the Localized Surface Plasmon Resonance of metallic particle,the optical reflection characteristics of nanoparticles arrays structure were calculated,and the nanoparticles size,periodic,and the surrounding refractive index are analysis to the influence of nanoparticle arrays structure reflection characteristics.By changing the environment refractive index,resonance wave position corresponding changes of the properties,can be used in the field of SPR sensor detection to the environment.Based on the above studies,the substrate of surface plasmon resonance sensor based on dielectric loaded array was investigated.The optical reflection spectra of silicon and silver particle array substrates are calculated respectively,compared with the metal Ag array,the local field coupling resonance effect of the dielectric Si array is stronger,and the corresponding reflection spectrum has more sharp resonance valley.Since the substrate sensing performance is affected by the substrate structure parameters,there are more complex between the constraints of each other,therefore,the influence of nanoparticles size,periodic,and substrate thickness on the peak position and intensity of SPR sensor structure was analysis by control variable method.The sensing performance parameters are computed under the same environment,which indicates that the sensitivity and quality factor of substrate based on dielectric silicon loaded array are better.Therefore,utilizing the scattering resonance effect on substrate based on dielectric loaded array is an effective way for increasing sensitivity of surface plasmon resonance sensor.