Numerical investigation of plasmonic properties of gold nanoshells

摘要

We numerically investigated plasmonic properties of gold coated 300 run core shell particles (CS). It is known that the surface plasmon decays into the medium that encompasses the metal nanoparticle. This decay converts changes in the local refractive index into a frequency shift of the SPR. In this work, the core material was polystyrene and the shell was a thin gold layer. We showed that this CS exhibits two plasmonic modes in the visible-near infrared regime. The blue end plasmonic mode was confined at the core-metal dielectric interface and the red end plasmonic mode was attributed to a surface mode that depends on dielectric properties of the surrounding medium. The application of the red end plasmonic mode as a surface plasmon resonance (SPR) sensor revealed that it exhibits wavelength shift of 764±13 nm per refractive index unit change of the surrounding medium (nm/RIU). Potential biomedical applications of these sensors are discussed.