Development of low-temperature SnO2–Au gas sensors for H2S detection in food freshness monitoring

Abstract

Tin Oxide (SnO₂) is widely used in chemiresistive applications due to its favorable electrical properties, high reliability, and enhanced sensitivity towards various gases. However, its high operating temperature limits its application in energy-efficient and compact modules. This study presents a novel SnO₂–Au 0.5 wt% chemiresistive gas sensor, optimized to operate at a low temperature of 200 °C, with high sensitivity (270.231, R_a/R_g) for 10 ppm H₂S gas. The sensor has been integrated into a handheld device to evaluate beef freshness by detecting H₂S gas emissions. The results demonstrate the sensor's potential to revolutionize the food industry by providing a quick, reliable, and non-invasive method for assessing meat quality, ensuring food safety, and reducing waste.