In the present study, we report the preparation of silver nanocrystals encapsulated in mesoporous silica nanoparticles (Ag-MSN) with increased stability and enhanced anti-bacterial potency. The morphology of the nanoparticles was characterized by scanning electron microscopy and transmission electron microscopy. X-ray diffraction analyses proved that the silver nanocrystals were truly embedded in the mesoporous silica nanoparticles. The antibacterial effect of silver nanoparticles was proved by plate count method and bacterial growth curve. Moreover, the marine bacterium V. natriegens showed weak attachment to the aluminum coated with Ag -MSN. The mechanism of reducing microbiological adhesion was also discussed.