Numerical study of optical and thermal response of gold and silver coated copper nanostructures for hyperthermia

The optical and thermal properties of nanoparticles have attracted much interest due to their extinction effectiveness in industries like electronics, medical devices, photonics, materials sciences, drug delivery, hyperthermia, etc. In this work, the optical response of eight different geometrical nanostructures, namely Solid-CuNS, Au-Ag-coated-Solid-CuNS, Hollow-CuNS, Au-Ag-coated-Hollow-CuNS, Solid-CuNR, Au-Ag-coated-Solid-CuNR, Hollow-CuNR, and Au-Ag-coated-Hollow-CuNR, were studied for hyperthermia. Finite element analysis was performed in COMSOL Multiphysics to simulate the optical and thermal responses of the nanostructures. The size range of nanostructures was selected differently based on the hyperthermia condition to attain a temperature between 42 degrees C and 46 degrees C. An appropriate temperature distribution of 43.8 degrees C was achieved in the 500 nm liver domain using an Au-Ag-coated-Solid-CuNS with D-sphere = 20 nm. The minimum thermal response was 42.1 degrees C for both Solid-CuNS and Solid-CuNR when D-sphere was 35 nm and L-cylinder was 35 nm. The highest electric field distribution of 11.2 V/m in the surrounding area was seen for Au-Ag-coated-Solid-CuNR, with an extinction resonance peak at 475 nm. On the other hand, the Au-Ag-coated-Solid-CuNS showed the least electric field distribution of 2.22 V/m with a corresponding resonance peak of 480 nm when D-sphere was 15 nm.