Silver is a known killer of harmful bacteria, and has already been incorporated into things such as antibacterial keyboards, washing machines, water filters, andplastic coatings for medical devices.
Now, scientists have added another potential product to the list: silver nanoparticle-impregnated “killer paper” packaging, that could help keep food from spoiling.
Led by Aharon Gedanken from Israel’s Bar-Ilan University, the team discovered that paper could be covered with silver nanoparticles through the application of ultrasonic radiation – a process known as ultrasonication. It involves the formation and subsequent collapse of acoustic bubbles near a solid surface, which creates microjets that throw the desired nanoparticles onto that surface. To the team’s knowledge, this was only the second time that ultrasonication had ever been attempted on paper.
Unlike previous attempts at creating antibacterial paper, this one-step method was reportedly quite effective, and produced a smooth, homogenous, long-lasting coating. By varying the nanoparticle concentration and the application time, the thickness of the coating could be varied as needed. When exposed toE. coli and S. aureus bacteria, both of which cause food poisoning, the paper killed them all off within three hours.