Fano resonance is a branch of surface plasmonics that has become a hot topic in sensing due to its asymmetric response spectrum, field enhancement effect and high sensitivity to refractive index (RI). In this research a plasmonic biosensor has been designed and simulated based on Mach-Zehnder interferometer. The simulations show that, the designed biosensor is able to detect changes of the RI of the surrounding media. The refractive indices (RIs) selected in this paper cover a wide range of RIs for biological samples. However, it is possible to accommodate media with RIs other than those in this specific range. The biosensor's sensing performance embedded in the sample has been tested in different conditions. Different frequencies can be achieved by changing the sample RI.
