Colorimetric Sensors Based on Multifunctional Polymers for Highly Sensitive Detection of Food Spoilage

Although numerous colorimetric food sensors exhibiting a color change when exposed to spoiled food have been developed recently, few of them could meet all the requirements in terms of facile fabrication, high sensitivity, and satisfying reliability. Here, we report a series of multifunctional polymer-dye adducts to construct the desirable colorimetric sensors for food sensing. Through the use of two different biogenic amine-sensitive dyes (zwitterionic rhodamine and fluorescein) with different color changes as the sensing motifs, our polymeric sensor could be facilely coated directly on the surface of commercial plastic wrap such as PET with outstanding sensing performance, for example, multicolor transition (pink–colorless–yellow), sensitivity (1.8 nmol), selectivity (only biogenic amines), long-term stability, and real-time colorimetric response.