Infectious disease caused by bacteria has created a big health problem all over the world in modern medicine.Therefore,antibiotics have played a great role in our daily life,especially for the antibacterial application.But the abuse of antibiotics has also led to some new problems,such as the failure of antibiotics,bacterial resistance enhancement and also the generation of "superbugs".In recent years,the research on antibacterial nanomaterials has paved a new way to fight with bacteria.The antibacterial principle of these nanomaterials is via the production of free radicals which directly cause bacteria damage without targeting a very specific step in their metabolic pathways-as most antibiotics do.