Cu2O nanocubes as gas sensing elements for food packaging applications

Intelligent packaging has attracted research interest during the last decades. More specifically, food packaging is of great importance due to the utmost need to monitor and maintain food quality until consumption. Thus, there is a high demand for sensors capable of detecting gases such as CO₂, emitted by packaged meat or chicken which serve as freshness indicators. In the present work, a sensor based on Cu₂O nanocubes was fabricated and tested against CO₂ at room temperature. Cu₂O nanocubes were synthesized by solution-based methods and deposited on commercial interdigitated electrodes. Specifically, the Cu₂O-based sensor successfully detected down to 5% CO₂ (50,000 ppm) in the ambient atmosphere, at room temperature, with a response time of less than 90 s. This level of CO₂ is in the range that indicates the unsuitability of packaged meat for consumption. Furthermore, the sensor was able to maintain its response to CO₂ after being stored in the fridge for 20 days, showcasing its endurance under food maintenance conditions.