Microscopic view of Escherichia coli. (Credit: FDA)

E. coli (Credit: FDA)

Nanotechnology is key to the development of a new paint that reportedly has the ability to kill antibiotic-resistant superbugs, according to a report from Manchester Metropolitan University researcher Lucia Caballero at a September 2008 meeting of the Society for General Microbiology. Caballero reports that, when exposed to fluorescent light or the sun’s ultraviolet rays, paints containing nanoparticles of titanium dioxide can kill potentially fatal bacteria. The particles do this, the researcher says, by absorbing the light and producing active molecules that “clean up the painted surfaces.” Caballero made this discovery by studying the ability of Escherichia coli, the bacterium that causes food poisoning, to survive under diverse types and intensities of light when placed on paints made from various formulas.

“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,” Caballero says.

He also found that the antibacterial efficacy of titanium dioxide-enhanced paints decreased when common additives, such as calcium carbonate, silica or talc, were added to the paint’s formulation. As an example, Caballero says:

“If calcium carbonate is present, the kill rate drops by up to 80 percent. Our tests on a commercially available paint showed that the ability of the paint to inactivate bacteria was massively reduced compared with a paint formulation which did not contain such additives.”

Caballero says the paint could also improve hygiene in child-care facilities, public conveniences, domestic bathrooms and a wide range of other environments.

“In all these places,” Caballero notes, “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.”