Refractive index sensing performance of a bimetallic core-shell nanotube

Abstract

Abstract The sensing performance of a bimetallic core-shell nanotube is studied theoretically based on the theory of TE-polarized light scattering by a multilayer infinite cylinder. The nanotube consists of a metallic core and a metallic shell with the analyte is inserted between the core and the shell. It is found that the absorption efficiency spectra of a bimetallic core-shell nanotube exhibit three resonance peaks correspond to the dipole, quadrupole and sextupole mode. As the refractive index of the analyte increased from n2 = 1.33 to n2 = 1.45, these resonance peaks are linearly redshifted. By calculating the figure of merit (FOM), it is found that the high sensing performance with FOM > 100 could be achieved. The dipole mode exhibits a higher sensing performance as compared to the other modes. Finally, the sensing performance is very sensitive to variations of the geometrical parameter and the background medium of the nanotube.