Nanometeric plasmonic refractive index senor

A novel surface plasmon-polaritons (SPPs) refractive index sensor based on tooth-shaped metal–insulator–metal structure is proposed and numerically simulated by using the finite difference time domain method with perfectly matched layer absorbing boundary condition. Both analytic and simulated results show that the transmission minima wavelengths in the transmitted spectrum of the sensor have a linear relationship with the refractive index of material under sensing. Based on the relationship, the refractive index of the material can be obtained from the detection of one of the transmission minima wavelengths in the transmitted spectrum. The resolution of refractive index of the nanometeric sensor can reach as high as 10− 6, given the wavelength resolution of 0.01 nm. It could be applied to high-resolution biological sensing.