Potential applications of nanoshell bow-tie antennas for biological imaging and hyperthermia therapy

Abstract

Silver nanoshell bow-tie antennas, two separate triangular dielectric cores covered by thin silver shells, have the potential of being used in different absorption- and scattering-based applications. The fields are highly localized in the gap region between the two components of the antenna. The dependence of the near-field and far-field spectra of silica-core silver nanoshells on antenna geometrical parameters, such as length, bow angle, gap width, and shell thickness, are investigated by applying the finite element method. Also, the effect of the dielectric permittivity of the antenna core is theoretically studied. The results show how the position and intensity of the electric field, absorption, scattering, and extinction resonance peak can be tuned within visible and near-infrared regions. By investigating the absorption and scattering spectra, we have designed appropriate silver nanoshell bow-tie antennas for the absorption- and scattering-based applications, such as hyperthermia therapy and biological imaging. The introduced nanoshells have high potential to be used as effective contrast and therapeutic agents.