Multifunctional Fe3O4@C@Ag hybrid nanoparticles as dual modal imaging probes and near-infrared light-responsive drug delivery platform

Multifunctional nanocarriers based on Fe3O4@C@Ag hybrid nanoparticles with a diameter of 200 nm were fabricated by a facile method. Silver (Ag) nanoparticles were deposited onto the surface of Fe3O4@C nanospheres in dimethyl formamide (DMF) solution by reducing silver nitrate (AgNO3) with glucose. The nanocarriers of doxorubicin (DOX) with a high loading content of 997 mg/g and near-infrared (NIR) light-responsive drug delivery based on Ag nanoparticles were realized. Strong fluorescence can be observed in cell nucleus due to the presence of DOX after irradiated by NIR, and most cells were in the state of apoptosis, which indicates NIR-regulated drug release was realized. Moreover, measurements show that the nanocarriers could also be used as magnetic resonance imaging (MRI) contrast agents and fluorescent probes. The combination of synergistic NIR controlled drug release and dual modal imaging of MRI and two-photon fluorescence (TPF) imaging could lead to a potential multifunctional system for biomedical diagnosis and therapy.