Food quality assessment using chemoresistive gas sensors: achievements and future perspectives

Real-time monitoring of food freshness facilitates the supply of safe and high-quality food products to customers. Various gases, including C2H4, NH3, C3H9N, and H2S, can be generated during the spoilage or ripening process of food, providing insights into the state of food freshness. Chemoresistive gas sensors represent one of the reliable pathways to assess food quality due to their high sensitivity, fast response speed, and easy integration. In this paper, we review recent progress in chemoresistive gas sensors for applications in food quality monitoring. Diverse materials, such as metal oxides, carbon-based materials, transition metal dichalcogenides, and other emerging materials, have been proposed with discussions on their sensing mechanisms. This review primarily focuses on the key strategies to enhance the sensitivity and selectivity of specific food quality marker gases using the chemical properties of materials. Additionally, we address the remaining challenges hindering the practical application of chemoresistive gas sensors, such as water poisoning, power consumption, and sensor reliability, while proposing potential solutions. The chemoresistive sensor platform, encompassing functional sensing materials and data recognition systems, can pave the way for real-time food quality monitoring technology in the future.