ForceSpun polydiacetylene nanofibers as colorimetric sensor for food spoilage detection

[Display omitted] •PDA nanofiber mats are fabricated by Forcespinning® technique.•The PDA nanofibers can monitor and assess meat deterioration and freshness.•The PDA nanofibers possess fast response, excellent sensitivity and long shelf life.•PDA nanofibers made from ECDA monomer have superior performance. Due to health and economic concerns, increasing attention has been attracted to the safety and quality control of food, particularly meat and seafood. Ammonia and biogenic amines (BAs), such as trimethylamine, putrescine and cadaverine, are released during the decomposition of meat protein. Therefore, the sensitive detection of the released BAs is crucial to the assessment of the safety and quality of meat products during storage, transportation and consumption. In this study, we have developed silica-reinforced polydiacetylene (PDA) nanofiber mats by a novel Forcespinning® technique. These PDA nanofibers demonstrate optical sensing of BAs owing to their strong electrostatic interaction with carboxylate ions of the PDA and amine ions in the BA molecules. Specifically, the PDA nanofibers produce a color transition from blue-to-red plus an enhancement of its fluorescence. PDA nanofibers were prepared from two different monomers and their amine sensing properties are evaluated and compared. The PDA nanofibers made from 5,7-eicosadienoic acid (ECDA) demonstrate higher performance and can determine amine vapor concentration with a detection limit of ˜7 ppm in a few minutes. An effective colorimetric response was also obtained when evaluating the sensing ability of the nanofibers to BA vapors from actual spoiling meat products including chicken, beef, fish and pork. Overall, our forcespun PDA nanofibers demonstrated promising colorimetric detection of meat spoilage based on the released amine vapors during the food degradation. These nanofibers are suitable for real-time and in situ monitoring and assessment of meat deterioration and freshness.