A new material, called “killer paper”, which helps preserve foods by fighting the bacteria that cause spoilage, has been developed for use as a new food packaging material. Israeli and Russian scientists have discovered an effective, long-lasting method for depositing silver nanoparticles on the surface of paper that involves ultrasound. The scientists are reporting that successful laboratory tests show the paper has potent antibacterial activity against E. coli and S. aureus, two causes of bacterial food poisoning. The paper killed all of the bacteria in just three hours. The paper could provide an alternative to common food preservation methods such as radiation, heat treatment and low temperature storage. The team’s work was described in the journal Langmuir.