Facilely Processable Dual-Color Ratiometric Fluorescent Sensors for Highly Sensitive Detection of Food Spoilage

Spoiled food, especially seafood, poses a huge challengeto foodsafety and human health, which should be addressed through early monitoringand warning of freshness. Despite the fact that several food colorimetricsensors have been reported recently, only a small number of them canmatch the demands of easy manufacturing, high sensitivity, and satisfactoryreliability. Herein, we report a type of dual-color ratiometric compositesas fluorescent sensors (DUCS) with good processability,which offers the superior real-time and visual detection of seafoodspoilage. A visually detectable colorimetric sensitivity under portableUV light irradiation has been achieved for seafood stored at roomtemperature for 4-6 h (response time variable with differentfood ingredients). Moreover, the ease and versatility of our formulation,composed of organic fluorophores, polymers, and additives as composites,has enabled facile processing, including drop-coating and stamp-patterning,which would facilitate a broad scope of applications for food sensingand beyond.