Emerging liquid metal-based sensors for food quality monitoring

Sensor technology plays a pivotal role in food quality control by enabling real-time monitoring of critical indicators. As the food industry continues to evolve, sensors must adapt to the diverse demands of food processing and production environments. Among the various sensors explored, liquid metals (LMs) have emerged as promising due to their low melting point, high conductivity, fluidity, ductility, and biocompatibility, which contribute to their high sensitivity in detecting minor physical and chemical changes. This review firstly summarizes the fundamental properties of LMs and examined the impact of oxide films on their fabrication and sensing application. The principles of various LMs sensing technologies, surface modification methods, and recent advancements in sensor manufacturing, including integration and miniaturization, were described separately. Moreover, the applications of LMs sensing technologies in monitoring temperature, gases, ions, and molecules were comprehensively generalized. Notably, sensors based on LMs exhibited advantages over other sensors, including ease of manufacturing, broad detection range, high sensitivity, multiple signal options, and robust stability. This emerging sensing technologies have significant potential for simultaneously monitoring diverse signal factors, enhancing the precision and efficiency of food quality control. In addition, challenges and future trends for LMs sensor in food field are also proposed.