Development of biosafe MOF-based highly sensitive carboxymethyl cellulose interpenetrating gelatin network smart freshness aerogel tags for real-time graded shrimp freshness monitoring

Abstract

With the growing demand for food freshness, developing ammonia-sensitive smart tags for real-time monitoring of animal-derived foods has become increasingly important. In this study, we successfully synthesized Biosafe-MOF nanocrystals with excellent ammonia sensitivity and incorporated them into gelatin/carboxymethyl cellulose (CMC) aerogels. The effects of Biosafe-MOF incorporation on the structure and sensing-related properties of gelatin/CMC aerogels were systematically investigated. The results demonstrated that Biosafe-MOF nanofillers were distributed uniformly within the gelatin/CMC matrix, and the aerogels exhibited large pores and high porosity. The resulting aerogels showed stable structure and distinct ammonia-responsive color-changing capability. When applied to monitor shrimp freshness, the smart freshness tag Gelatin/CMC@Biosafe-MOF^2.0 enabled graded monitoring of shrimp freshness. Within the edible range of shrimp (TVB-N < 20 mg/100 g), the smart freshness tag achieved visual color changes (from green to brown). These results demonstrate that the developed Gelatin/CMC@Biosafe-MOF^2.0 aerogel functions as an effective ammonia-responsive smart tag for real-time freshness monitoring of shrimp.

Keywords: Aerogel sensor; Ammonia sensitivity; Biosafe-MOF; Graded monitoring; Smart freshness tag.