influences of phosphorene nanotubes(pnts) on improving the performance of an spr-biosensor

In this paper, the effect of phosphorene nanotubes(pnts) layer with different diameters and rolling directions on the structure of surface plasmon resonance(spr) biosensor in a lumerical software environment is simulated and investigated. the main structure is based on the structure of kretschmann and the use of the bk7 prism, the gold(au) layer, and the end layer of phosphorene nanotubes. the reflectance curves of the proposed sprbiosensors were obtained, analyzed, and compared for different modes in refractive indices n = 1.33 and 1.339, resembling a neutral watery and a bacterial medium, respectively. the results show that the minimum reflection is occurred for 30nm au in an spr resonance angle of θ = 71.59°, while adding phosphorene nanotubes, it is observed that in diameter of 10.08a and an armchair rolling direction configurations on the au layer becomes desirable. it was observed that the minimum reflectance of 0.199 is achieved for apnts(10.08a) layer on 30nm au. the combination also yields a sensitivity of 152 °/riu for δn = 0.009 with a great detection accuracy of 0.079. the results show that the phosphorene nanotubes layer has a positive effect on the spr-biosensor, and this layer can be used as a controlling factor in spr- biosensors.