A card instead of a lab: A ligand embedded in a bio-composite of starch/gelatin intelligent film for milk quality test followed by colorimetric analysis.

Milk adulteration analysis at different stages of the production chain, which profiteers widely use to mask milk quality parameters, is problematic. We prepared selective intelligent thin bio-films and a dedicated app to test milk adulteration in an out-of-lab setting. In this regard, each reagent is immobilized on a piece of starch/gelatin film as color-changeable polymeric support, which is then pasted onto a transparent test card.