Graphene-based magnetic plasmonic nanocomposite for dual bioimaging and photothermal therapy

In recent years, graphene and graphene-based nanocomposites owning to their highly enriched physical and chemical properties have been widely explored for applications in many different fields including biomedicine. In the present work, we decorate graphene oxide (GO) by both iron oxide nanoparticles (IONPs) and gold, forming a multi-functional magnetic & plasmonic GO–IONP–Au nanocomposite with strong superparamagnetism and significantly enhanced optical absorbance in the near-infrared (NIR) region. We then coat the nanocomposite with polyethylene glycol (PEG), obtaining GO–IONP–Au–PEG with high stability in physiological environments and no significant in vitro toxicity. Remarkably enhanced photothermal cancer ablation effect using GO–IONP–Au–PEG is realized in comparison to PEGylated GO used in our earlier studies, as demonstrated in both in vitro cell tests and in vivo animal experiments. Moreover, the IONP and Au compartments in the GO–IONP–Au–PEG nanocomposite could be further taken advantages for magnetic resonance (MR) and X-ray dual-modal imaging. Our work shows the promise of using graphene-based multi-functional nanocomposite as cancer theranostics.