A high-stable and sensitive colorimetric nanofiber sensor based on PCL incorporating anthocyanins for shrimp freshness

A novel bilayer colorimetric film incorporating polycaprolactone (PCL) with clitoria ternatea Linn anthocyanin (CA) via electrospinning was designed. The PCL nanofibers layer acted as a protective layer against harsh environments as the strong hydrophobic with the WCA (water contact angle) values of 101.79°. The PCL-CA layer worked as an indicator for its significant color changes for pH. The sensitivity test verified the ammonia cycler reversibility of the nanofibers is promising for re-use packaging. And the PCL/PCL-CA film was characterized as suitable WVP (water vapour permeability), and the lower velocity of water penetrating. Moreover, higher elongation at break (240.431%), and color stability were achieved. Besides, the film exhibited the color change from pale-blue to yellow-green response as an indication of shrimp spoilage (21 h). These results suggested the potential application of the PCL/PCL-CA film for a reusable freshness sensor tool in food packaging.