A new plastic film glows to flag food contaminated with dangerous microbes

Pathogen detectors built into plastic patches could someday spare you food poisoning.

Carlos Filipe, a chemical engineer at McMaster University in Hamilton, Canada, and colleagues have developed a new kind of flexible film that’s coated in molecules that glow when they touch E. coli cells. This type of sensor also glows in the presence of molecules secreted by E. coli, so the material doesn’t have to be in direct contact with bacterial cells to flag food contamination.

Sensors about the size of postage stamps fluoresced brightly when tested on tainted meat and apple juice, but not when the sensors touched unspoiled samples, the researchers report online April 6 in ACS Nano.

Next, the scientists plan to make films that glow in the presence of other bacteria, such as Salmonella, says study coauthor Tohid Didar, a mechanical engineer at McMaster. Food packaging equipped with such microbe monitors could help curb the spread of foodborne illness, which kills about 420,000 people worldwide each year, according to the World Health Organization.  

The glow of the sensors must be viewed under an ultraviolet lamp or with a fluorescence scanner. But other scientists have developed matchbox-sized smartphone attachments that detect fluorescence, which people could use to check packaged food at home before opening it, Filipe says. Grocery stores could also provide scanners so customers can check food before buying it.