Robust H₂S Sensing with Pt/Fe-TiN Fuel Cell Sensors for Cold-Chain Meat Spoilage Monitoring

Food spoilage leads to significant waste and poses serious health risks, yet real-time monitoring solutions remain limited throughout the supply chain and storage. Herein, we develop a Pt/Fe-TiN-based fuel cell gas sensor for highly sensitive and selective detection of hydrogen sulfide (H₂S), a key indicator of meat spoilage. Fe doping in TiN effectively modulates the electronic structure of Pt, enhancing H₂S sensitivity and mitigating humidity interference. The Pt/Fe-TiN sensor achieves a detection limit of 100 ppb and remains fully operational even at -18 °C. Compared to commercial Pt/C electrodes, it exhibits superior stability, retaining over 97% of its sensitivity after 60 days under high humidity. Furthermore, a real-time H₂S monitoring device integrated with a smartphone interface was developed for continuous spoilage detection in meat storage. This work provides a practical, real-time sensing platform for food safety monitoring, contributing to reduced waste and improved supply chain transparency.