The process of destroying microorganisms is called sterilization and removing all pathogenic agents from objects is termed as disinfection. Heat, chemicals, irradiation, high pressure or filtration are commonly used to remove microbes from surfaces, medical appliances, linen etc., to perform a sterilization and disinfection. To contain the pathogenic organisms is a main concern of health care or in the process of food production and consumption.

But increased resistance of many pathogenic species is reported to the commonly used disinfectant and antibiotics. Hence new types of safe and cost-effective antimicrobial active materials are needed by this sector. Reported studies indicate that various nanomaterials exhibit excellent antimicrobial properties.

Nanomaterials may interact with cellular wall and disintegrate it. They can accumulate inside the cell or may lead to ROS (reactive oxygen species) production, thus to destroy the cell integrity. The cytotoxic mechanism is via DNA damage.

Silver compounds and silver ions that have been recognized as active antimicrobial agents. Silica spheres with silver nanoparticles and Ag-Au doped material prepared by the cementation process are few active antimicrobial agents. Ag-SiO2-Au doped nanomaterials demonstrated antibacterial activity.

Silver and silver-gold doped silica nanospheres revealed antibacterial activity against Escherichia coli. For the higher nanoparticles concentration, the antimicrobial effectiveness was higher.

Researchers from Wroclaw University of Technology, Poland have reported that sol-gel route is a very convenient method to produce various materials and it is frequently exploited for nanomaterials. Composite materials in the form of nanopowders may be produced or they may be deposited on various substrates, e.g. fibers, metals etc. The photocatalytic properties of such materials may be used for photosterilization processes. Moreover, it is possible to apply not only UV but the light in visible range.