Graphene oxide and reduced graphene oxide nanocomposites grafted with hollow gold nanoshells as photothermal agents

Nanocomposites based on graphene oxide (GO) or reduced graphene oxide (rGO) grafted with hollow gold nanoshells (HGNs) were developed as enhanced photothermal agents with improved biocompatibility. Infrared and Raman spectroscopy allowed determining that graphene was highly oxidized due to the presence of oxygenated groups that allowed further functionalization and provided anchor points for the grafting of HGNs. Using HRTEM and STEM, good dispersion of the HGN on the surface of the graphitic materials was observed. Meanwhile, using UV–Vis spectroscopy, an increase of absorbance in the near-infrared region was appreciated, resulting in an enhancement of the photothermal properties of the nanocomposites in contrast to the materials separately. Remarkable temperature increases were obtained in short periods of irradiation using a low-power laser. Moreover, a decrease in the cytotoxicity of GO and rGO was observed in the human neuronal line hNS1 under the presence of the plasmonic nanoparticles on the surface.