Researchers create contamination test for dairy products, using technology that can be printed inside containers

https://phys.org/news/2021-12-contamination-dairy-products-technology.html

"can be adapted to detect the most common food pathogens and is also expected to be effective for use with other foods and beverages... The test works by printing the inner surface of a container with a tasteless, food-safe patch that repels everything but the target organisms, using a biosensor that triggers a change in the patch when such organisms are detected... can detect even trace amounts of the bacterium... can be read, either visually or with a scanner, without opening the package"

Related: Successful optical biosensing using dual optical combs: High sensitivity and rapid detection of biomolecules

https://phys.org/news/2023-09-successful-optical-biosensing-dual-high.html