Optical and Photothermal Properties of Graphene Coated Au–Ag Hollow Nanoshells: A Modeling for Efficient Photothermal Therapy

Abstract

We study the optical and photothermal properties of graphene coated gold−silver alloy hollow nanoshells (Au−Ag HNSs) using the effective medium theory combined with the Pennes bioheat and Arrhenius equations. To increase the stability of Au−Ag HNSs in the presence of oxidants, acid, and heating, we propose the use of graphene as a protective shell on Au−Ag HNSs in photothermal therapy (PTT) applications. Calculating the extinction efficiency in tumor tissue, we show that the surface plasmon resonant (SPR) peak of graphene coated Au−Ag HNSs can be easily adjusted within a wide range of biological windows by changing the inner radius, the Au−Ag shell thickness, and the alloy composition of Au−Ag. In addition, the effect of concentration of nanoparticles and the number of graphene layers on the temperature rise in the tumor tissue are investigated.To achieve a comprehensive study, the thermal damage in tumor tissue is also investigated and the region of tumor in which the irreversible thermal damage can occur is determined. Our results suggest that graphene coated Au−Ag HNSs can be used as an excellent class of nanoagents for PTT applications.

Nanoparticles Engineering by Pulsed Laser Ablation in Liquids: Concepts and Applications

“…where x denotes the Au molar fraction in the Au−Ag alloy [149]. The simulation results shown in Figure 14b agree with the experimental results concerning the plasmon resonance position.…”

“…In this case a dielectric environment (water) where bodies with homogeneous and isotropic dielectric functions are separated by abrupt interfaces is assumed, thus solving Maxwell equations using the boundary conditions at the particle boundaries. As for the dielectric function of the considered Au/Ag alloy, a weighted average method was used, in which the dielectric function of the alloy is defined as: ε alloy ( ω ) = x ε Au ( ω ) + (1 − x ) ε Ag ( ω ) where x denotes the Au molar fraction in the Au−Ag alloy [ 149 ].…”

2D Material‐Based Optical Biosensor: Status and Prospect

“…Reproduced with permission. [ 195 ] Copyright 2019, American Chemical Society. g) Surface plasmon resonance sensors for DNA hybridization with graphene WS 2 coatings.…”

“…For example, Farokhnezhad et al. Studied the optical and photothermal properties of graphene coated gold silver alloy hollow nanoshell and found that it is suitable for a class of excellent photothermal treatment nanomaterials, [ 195 ] as shown in Figure 26d . In the experiment, metal nanoparticles have great photothermal conversion efficiency and excellent optical properties, which are suitable for photothermal therapy.…”

Simulation of Thermal Phenomena in Body Tissue Caused by Surface Plasmon Resonance in Metal-Graphene Nanoparticles

“…   G is the graphene conductivity, which is defined as the sum of the contributions of interband and intraband transitions according to the Kubo theory [27] …”