Nanoparticles size detection method based on surface plasmon polaritons in graphene nanopore

Abstract

A nanometric plasmonic size detector based on surface plasmon polaritons (SPPs) in graphene is proposed and the excitation of TM surface plasmon polaritons by a point source is simulated by using finite difference frequency domain (FDFD) method. Here we show that in the presence of graphene layer and GaAs as the substrate strong E-filed confinement is achievable. This detector provides the possibility of optical detection of size of the nanoparticles with smaller dimensions than free space wavelength by calculating transmittance of plasmonic wave on the graphene nanopore. There is a nanopore in the middle of structure that the nanoparticle is placed inside it. The SPP wavelength is 17.474nm which is finely matched with 17.101nm theoretical value by simulating in 40 THz frequency. Results show that the transmittance have a relatively linear relationship with nanopore radius and the radius of nanoparticles under detection. Results indicate that the proposed method can detect different nanoparticles with acceptable accuracy to overcome inherent problems in electrical sensing specially for bio sensing applications.