A label-free graphene-based nanosensor using surface plasmon resonance for biomaterials detection

Graphene biosensors have received more and more attention over the past two decades in the modern fields including labeled, and label-free sensing owing to their ability to harness of electromagnetic fields in a fantastic way. Among these, label-free graphene plasmonic biosensors have been received significant attention for nano-scale applications. The main aim of this work is to study the detection capacity of the biomaterial-based graphene plasmonic biosensor using three-dimensional finite difference time domain (3D-FDTD) method. Herein, taking the advantages of the strong light-matter interaction of graphene layer and its highly tunable optical properties, a new smart biosensor for colorless biomaterial detection is developed. To evaluate the performance parameters of the proposed bio-nanochip sensor, the effects of different biomaterial are considered. Compared to the previous works, the footprint of the proposed biosensor is too small, i.e. lambda/10 where lambda is the incident wavelength. Also, the sensitivity and figure of merit (FoM) as main parameters of the biosensor are calculated. Numerical results show that the maximum shift of resonance wavelength is around of 100 nm as the variation of refractive index of biomaterials is 0.3. Through the above result, the maximum sensitivity and FoM of the biosensor are respectively 333.3 nm/RIU and 16.665 RIU.