The Wireless Gas Sensor Node for Indirectly <i>Listeria Monocytogenes</i> Monitoring

As a common foodborne pathogen, the bacterium Listeria monocytogenes is highly resistant to unfavorable survival environments such as low temperatures and acidity. It is extremely infectious and lethal, making it a significant threat to food safety. Current culture identification and biochemical sensor methods for Listeria detection are not suitable for real-time and wide-area detection. In this article, we use a gas sensor to detect the 3-hydroxy-2-butanone (3H-2B) biomarker for indirect monitoring of L. monocytogenes. Combined with the wireless sensor network, we design the low-power (PWR) gas sensor node. The designed circuit achieves 0.005–10-ppm range 3H-2B detection for early detection of possible L. monocytogenes. We also analyze the correspondent biological detection limit based on the gas sensor performance. The wireless communication distance of the gas sensor node is up to 1 km, and it can work continuously for nearly half a year with one measurement every 30 min. We also designed the energy harvesting circuits, allowing charging by solar panels, thermal electric generators, etc. It can further extend the lifetime of the node. The gas sensor node is suitable for real-time multipoint monitoring in food factories and can also be used in vehicles to monitor the cold chain.