Our team designed and developed a smart food label to ensure food safety by detecting the biogenic amines produced during food spoilage without contacting the food. Based on a complex that can respond quickly to biogenic amines, the label will change from dark green to orange-red when the food decays. Unlike traditional chromatographic methods or electronic sensors, this smart label is passive (no battery is required to power the label) and low cost, and responds quickly and reliably. We aim to promote it to consumers to help ensure food safety and to the food industry to reduce food losses.