MOF‐Derived ZrO ₂ @C for Real‐Time H ₂ S Monitoring in Food Freshness Assessment

Effective monitoring of food spoilage is crucial for global food security, as nearly one‐third of the food produced worldwide each year is wasted and 29% of the population faces nutritional risk. However, existing gas sensing technologies suffer from high material costs, limited sensitivity, and inefficient data transmission. Here, we report a low‐cost electrochemical H 2 S sensor based on a metal‐organic framework‐derived ZrO 2 @C‐900 composite. This active material costs only US$0.09 g −1 , has high sensitivity, and retains 97% of its initial performance after 120 days of continuous operation. This device integrates Bluetooth transmission functionality to monitor H 2 S release in real time as a biomarker of food spoilage. This sensor operates stably under high humidity and low temperature conditions, making it suitable for use in intelligent cold chain systems.