Protein-Templated Core/Shell Au Nanostructures for Intracellular Reactive Oxygen Species Detection by SERS

Core/shell gold raspberry nanostructures capable of multiple therapeutic functionalities were synthesized using a template composed of monodispersed anionic protein (bovine serum albumin) nanoparticles coated with a cationic biopolymer (poly -L-lysine). The nanostructures exhibited high photothermal conversion efficiency when exposed to a near-infrared (NIR) laser, which led to significant cellular inhibition of A549 human lung cancer cells due to intracellular hyperthermia. The raspberry structures also provided hot spots for surface-enhanced Raman scattering (SERS) ratiometric sensing of intracellular reactive oxygen species (ROS) when modified with the Raman reporter molecule 4-aminothiophenol (4-ATP). ROS was detected in A549 lung cancer cells upon photothermal heating of internalized lung upon photothermal heating nanostructures, enabling a possible mechanism for feedback on therapeutic efficacy. This was confirmed by adding the antioxidant N-acetylcysteine (NAC) and using a complementary fluorescence technique, which showed that the amount of detectable intracellular ROS decreased. These safe-by-design gold raspberry nanostructures could be promising for simultaneous therapeutic applications and monitoring therapeutic efficacy.

Automated summary

Core/shell gold raspberry nanostructures with multiple therapeutic functionalities were synthesized and showed high photothermal conversion efficiency. They inhibited lung cancer cells through intracellular hyperthermia and detected reactive oxygen species using surface-enhanced Raman scattering. These safe-by-design nanostructures have potential for simultaneous therapeutic applications and monitoring therapeutic efficacy.