Developing a sensor layer for the optical detection of amines during food spoilage

A colourimetric sensor layer has been developed for ammonia and biogenic amines. Amine exposure induces a traffic light colour change from green to red. Recognition is performed by a pH indicator dye, covalently immobilised onto cellulose microparticles. The sensor microparticles are embedded into food-grade silicone. Selectivity of the pH indicator dye towards gaseous amine is obtained by complete embedding of the sensor particles within the ion-impermeable silicone. A response time of 1.5 h has been achieved, with a reverse response occurring after 20 h. This time frame is considered sufficient for spoilage processes. Cytotoxicity studies confirm the layers are non-toxic.