Preparation and characterization of a photocatalytic antibacterial material: Graphene oxide/TiO2/bacterial cellulose nanocomposite.

In this study, bacterial cellulose (BC) was used as a matrix to synthesize graphene oxide/Titanium dioxide (GOTiO2)-based hybrid materials. It was indicated by X-ray diffraction and selected area electron diffraction that the crystal structure of GOTiO2 was a mixed phase containing anatase and rutile. TiO2 nanoparticles were of 10-30nm diameters and densely anchored on graphene oxide sheets. Superior photocatalytic performance of the GOTiO2 was achieved under near UV excitation. The photocatalytic efficiency was optimized through controlling an appropriate calcined temperature. The obtained GOTiO2 nanoparticles were filled into porous BC matrix (GOTiO2/BC), and the photocatalytic properties of GOTiO2 nanoparticles were well maintained. Consistent with photocatalytic performance of TiO2, GOTiO2/BC generated reactive oxygen species after near ultraviolet irradiation. No dark cytotoxicity was observed at the long incubation time. In parallel, following exposure of Staphylococcus aureus cells to GOTiO2 and irradiation, a significant decrease in cell viability, as well as an increased production of reactive oxygen species was observed, which induced cellular death. The results indicated that GOTiO2/BC possess an excellent photodynamic antibacterial activity.