Ultrasensitive Plasmonic Imaging Sensor Based on Graphene and Silicon

We propose an ultrasensitive, accurate, and cost effective surface plasmon resonance sensor based on graphene-on-aluminum and silicon. An angular interrogation method has been theoretically used to study the performance of the sensor in terms of imaging sensitivity, which quantifies the rate of change of slopes of the reflectance curve close to resonance angle. Different optimized design parameters have been reported. It is found that the imaging sensitivity of an aluminum-based sensor is 750% greater than gold, the most widely used SPR active metal. However, graphene-on-aluminum not only prevents the aluminum oxidation but, a monolayer of graphene-on-aluminum exhibits ~400% larger imaging sensitivity compared to that of a conventional gold-film based SPR sensor.