Design of infrared surface plasmon resonance sensors based on graphene ribbon arrays

A surface plasmon resonance (SPR) based graphene sensor for infrared wavelength is presented. It consists of a graphene ribbon array on top of a quartz substrate. The refractive index changes above the sensor surface, which is due to the appearance of gas or the absorption of biomolecules, can be detected by measuring the resulting spectral shifts of the resonant transmission dip. The dynamic tunability of graphene enables the detectable refractive index changes covering a broadband wavelength range. The influence of Fermi level and the number of graphene layers on the performance of sensor are investigated in details, which should be useful for guiding the design of sensors based on a graphene ribbon array. The sensor can be used for sensing both gas and low-refractive-index materials in an aqueous environment. (C) 2014 Elsevier Ltd. All rights reserved