Efficient plasmonic-based biosensing for mixture of gases-far-and near field analysis

This research work presents the efficient excitation of surface Plasmon polaritons (SPPs) excitation at the interface of gold-dielectric. The calculated sensitivity results of SPPs for film thickness of 50 nm and 60 nm at a fixed optimized angle of 42.8° which give maximum electrical field intensity and by changing refractive index values of air from (1.002 to 1.008) by using COMSOL Multiphysics, RF module (version 5.3a). The special characteristic of SPP resonance is the wavelength dependence upon refractive index i.e. reflection curve shifts from visible to IR region elaborated in this research work. However, it is investigated that sensing could be possible when biomaterials attached to biosensors interact with SPP’s refractive index value changes. Moreover, Biosensors made by this approach are label free and very sensitive to diagnose various diseases, including cancer and open doors of their treatment by using the energy of these surface plasmon polaritons to kill unhealthy cells of cancer. The gold metal has been used which is an efficient metal and has a very strong optical response. It is worth mentioning that the unique property of gold metal is its hyper sensitive electric field generation associated with the excitation of the SPPs along the interface between metal and dielectric. These biosensors based upon the technique of surface plasmon resonance act as a tool in clinical diagnostics, drug injection, food quality checking and binding different molecules and replacing them with each other.