Multiplex detection of biogenic amines with SERS sensor array boosted by (metallo)porphyrin-based hydrogen-bonded organic frameworks.

Biogenic amines (BAs), primarily formed through the microbial degradation of proteins, are important markers indicating food fermentation and spoilage. On the demand of on-site monitoring of food quality and safety, electrochemical and optical sensors have been developed, focusing on the detection of the total volatile amines or a specific amine. However, the multiplex detection of BAs with high accuracy and sensitivity still remains a major challenge. The sensor array strategy that mimics the biological olfactory sense provides an effective and powerful route to achieve multiplex detection of BAs. Herein, (metallo)porphyrin-based hydrogen-bonded organic frameworks embedded with silver nanoparticles were prepared and used as receptors to construct the surface-enhanced Raman scattering (SERS) sensor array, leveraging the multiple chemical interactions and the sharp Raman signals of (metallo)porphyrins, and the porous and flexible structure of the supramolecular frameworks. This SERS sensor array demonstrated a successful discrimination of ten BAs, an accurate quantitation of three BAs, and a successful simultaneous determination of three BAs in pork samples. Using the total volatile basic nitrogen as a spoilage label, the platform achieved over 90% accuracies in freshness discriminations for pork, beef, and chicken samples. In comparison with the existing detection methods, the proposed SERS sensor array strategy based on porphyrin- and metalloporphyrin-based hydrogen-bonded organic frameworks exhibits operational simplicity, rapid response, high sensitivity, as well as multiplex detection capability. Thus, it demonstrates a significant practical potential for applications in the production line and the supply chain of foods.