Designing and developing biodegradable intelligent package used for monitoring spoilage seafood using aggregation-induced emission indicator

In this work, we applied a very sensitive aggregation-induced emission (AIE) indicator of 6,7-dimethyl-2-buthy-2,3-dimethphenyl-1,2-dihydroquinoxaline (H+DQ2) for monitoring seafood spoilage, which was labeled in a designed novel biodegradable package composed of a polylactic acid (PLA) tray and a poly (butylene adipate-co-terephthalate) (PBAT) film. Firstly, a polydimethylsiloxane (PDMS)-coated filter paper was employed as a hydrophobically basal-layer to deposit the H+DQ2 indicator. A maximum contact angle of around 138° and 1.5 times increase of the tensile strength were found at an optimal coating concentration of PDMS of 0.6 g/100 g. The developed H+DQ2 indicator showed a higher sensitivity upon exposure to ammonia vapors even at a low concentration of 1.3 × 104 mg/m3 and could be reused for over five cycles. The results showed that in applying to monitor the spoilage of shrimp, the color variations (from red to yellow) and fluorescence-emission (turn on) changes of the indicator were in a good agreement with the variation of total volatile basic nitrogen (from 10.52 mg/100 g to 31.03 mg/100 g) and colony forming units (from 4.4 log CFU/g to 6.5 log CFU/g) of prepackaged shrimps at 4 °C after stored five days. The developed intelligent packaging could provide a real-time and highly sensitive detection of seafood spoilage.