Development of indocyanine green loaded Au@Silica core shell nanoparticles for plasmonic enhanced light triggered therapy

Abstract Au@SiO 2 @mSiO 2 nanoparticles have been designed to combine photothermal therapy and photodynamic therapy for multifunction theranostics. It is well known that the deep red light at near infrared region has the largest penetration depth in tissue within the optical “transparent” window ranging from 650 to 1350 nm A typical fluorescent dye named indocyanine green (ICG), with a maximum absorption value of about 800 nm, serves as an excellent agent for photothermal and photodynamic therapy. However, the intrinsic drawbacks of ICG due to the stochastic nature of dye molecules, such as low quantum yield, poor photo- and thermal-stability in aqueous solution, hinder their biomedical applications. To tackle this, ICG has been loaded in well-designed Au@SiO 2 @mSiO 2 nanoplatforms to improve the corresponding photothermal and photodynamic therapy. Different configuration parameters have been explored both experimentally and theoretically. The optimal configuration achieved almost twice temperature increase, five times reactive oxygen species generation, and finally three times cancer cell killing ability in comparison with free ICG.