Highly Sensitive Hybrid Surface Plasmon Resonance Biosensor Utilizing Carbon Nanotube, Copper, Palladium and Black Phosphorus Layers

In this work, a hybrid surface plasmon resonance sensor structure comprising carbon nanotube, copper, palladium and black phosphorus layer is presented for the detect of water salinity concentration. The angular interrogation method is used to evaluate key performance parameters such as sensitivity, detection accuracy, figure of merit (FoM) and penetration depth (PD). The Cu and Pd layer thicknesses are optimized to obtained the maximum sensitivity. The maximum sensitivity of 485.57 °/refractive index unit (RIU) and FoM of 122.92/RIU are obtained at thickness of 41 nm for Cu and 15 nm for PD layer. Moreover, the penetration depth of 140.45 nm and 143.28 nm are obtained for refractive indices of 1.3300 and 1.3369, respectively, corresponding to different water salinity. The suggested sensor has strong field penetration and high sensitivity due to the integration of cutting-edge materials and optimized design, which makes it appropriate for the practical detection of larger macromolecules in biosensing applications.