A Swiss team led by professor Wendelin Stark (pictured) developed a film that inhibits pathogen growth with silver and calcium phosphate nanoparticles.

A team of Swiss chemical engineers has developed a film coated with nanoparticles of silver and calcium phosphate, which can be used in both food processing and packaging to inhibit pathogen growth.

The team, led by Wendelin Stark, assistant professor at the Institute for Chemical and Bioengineering of ETH Zurich, claims that the film is more lethal to the bacterium E. coli than traditional silicon-based silver preparations, leaving fewer than one bacterium out of a million to survive within 24 hours. According to Stark, the process revolves around bacteria’s reliance on calcium for metabolism and their consumption of calcium phosphate particles for nutrition.

“When the bacteria consume the calcium phosphate, thousands of small silver nanometer particles are released,” said Stark. “It is these tiny silver particles that kill the bacteria and prevent germs from growing and spreading.”

According to Stark, areas such as walls, conveyor belts and machine covers could be covered with the film to inhibit recontamination from product-touching surfaces.