Graphene-Coated Gold Chips for Enhanced Goos–Hanchen Shift Plasmonic Sensing

摘要

Plasmon-based sensing relies on the interaction of photons with nanostructuredmaterials. Surface plasmon resonance (SPR) biological and chemical sensorsoffer unique advantages of real-time and label-free detection techniques andtherefore, they have been around in the commercial market for many decades.The principle of the Goos–Hanchen (GH) shift, whereby linearly polarized lightundergoes a small lateral shift upon total internal reflection at a dielectric surface,is highly sensitive to refractive index (RI) changes in the sensing medium and canthus be utilized for plasmonic sensing. 2D materials such as graphene can boostthe plasmonic efficiency of these sensors because of their excellent opticalproperties. Herein, a customized GH shift–based SPR sensor is devised usinggraphene-coated Au chips. With the help of experimental results, it is shown thatgraphene can enhance the sensitivity of the conventional Au-only configuration2.35 times.