Nanoparticles in paint can kill bacteria

Research Lead

Scientists at Manchester Metropolitan University, UK, have discovered that nanoparticle-sized forms of titanium dioxide can kill bacteria and destroy dirt when they absorb ultraviolet light (UV) energy  and suggest the particles could be added to paint for use in hospital s and food processing plants.

The researchers looked at the survival Escherichia coli on different formulations of paints containing the titanium nanoparticles under different types and intensities of lights. "We found that paints containing titanium dioxide are more successful at killing bacteria if the concentration of the nanoparticles is stronger than in normal paint. Our best results showed that all the E. coli were killed under ordinary fluorescent lights," said one of the researchers, Lucia Caballero.

At the same time the work has shown that other common additives in paints, such as calcium carbonate, silica or talc decreased its antibacterial efficiency. “If calcium carbonate was present the kill rate dropped by up to 80 percent," said Caballero. “Our tests on a commercially available paint showed that its ability to inactivate bacteria was massively reduced compared with a paint formulation which did not contain such additives."

Caballero concluded that surface hygiene could be improved by the action of fluorescent light on catalytic surfaces such as paints containing nanotitanium. This would slow down contamination and save on the costs of cleaning maintenance.