Photocatalytic degradation of bacteriophages evidenced by atomic force microscopy

Methods to supply fresh water are becoming increasingly critical as the world population continues to grow. Small-diameter hazardous microbes such as viruses (20-100 nm diameter) can be filtered by size exclusion, but in this approach the filters are fouled. Thus, in our research, we are investigating an approach in which filters will be reusable. When exposed to ultraviolet (UV) illumination, titanate materials photocatalytically evolve (•)OH and O2(•-) radicals, which attack biological materials. In the proposed approach, titanate nanosheets are deposited on a substrate. Viruses adsorb on these nanosheets and degrade when exposed to UV light. Using atomic force microscopy (AFM), we image adsorbed viruses and demonstrate that they are removed by UV illumination in the presence of the nanosheets, but not in their absence.