Functionalization of graphene oxide surfaces with phosphorus dendrimer and dendron

We report a novel approach for functionalizing the graphene oxide (GO) surface with AB5 phosphorus dendron, and dendrimer. First, a dendrimer was prepared having tyramine functions on the surface, while the AB5 dendrons were synthesized and characterized having either pyridine derivatives or ethacrynic acid terminal functions and a tyramine derivative linked to the core. Subsequently, these macromolecules were grafted onto the GO surface via covalent bonding. The resulting GO and modified-GO-AB5 dendron/dendrimer materials have been characterized by Fourier Transform Infrared (FTIR), Raman spectroscopy (RS), Thermogravimetric Analysis (TGA), Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) and Energy Dispersive X-ray spectroscopy (EDX) analyses. The dendritic structures and the functionalized materials were evaluated for their biological activity against HCT116 (human colon cancer), and against the non-cancerous RPE1 cells for the most active, to evaluate the safety.