Albumin from bovine serum-prepared fluorescent hydrogel for real-time monitoring of H2S and food freshness.

In this work, A fluorescent intelligent label (BE-P) was prepared for real-time monitoring of food freshness by grafting an H₂S-sensitive small-molecule fluorescent probe (NP-H₂S) onto a hydrogel cross-linked with bovine serum albumin (BSA) and ethylene glycol diglycidyl ether (EGDE). The results indicated that the addition of NP-H2S had no significant effect on the properties of BE-P, and the BE-P exhibited thermal stability and mechanical properties. Impressively, BE-P demonstrated good color stability, storage stability, and high sensitivity to H2S gas (LOD: 5.5 ppb). Additionally, BE-P was successfully used to monitor the freshness of pork, beef, and shrimp at 4°C and 25°C with satisfactory results. Moreover, the color changes in the BE-P correlated with changes in total volatile basic nitrogen (TVB-N) and total viable count (TVC) in the food samples (R2 > 0.97). Therefore, the developed intelligent label provides new insights for the development of multi-marker activated multicolor fluorescent intelligent labels.