Marker could be a simple answer to ensuring provenance of drugs
A group of researchers based in the US and Korea have developed and tested an edible matrix code made of silk that can be attached to tablets or added to liquids as an anticounterfeit measure. The tag is made of silk and is invisible to the eye, but can be picked up by specific optical filters on a smartphone camera that can pick up fluorescence.
Drug counterfeiting is an increasing problem. Every year it causes thousands of deaths and poisonings, and recent increases in online sales have only made the problem harder to manage.