Monitoring plants health in greenhouse for space missions

We developed a sensor array made up of metal oxide thin films for the detection of stress molecules produced by plants in greenhouses for manned long term space missions. This sensor array was coupled with other sensors for illumination, CO2 and humidity to realize an advanced hybrid electronic nose that was successfully employed to monitor plant growth inside a greenhouse. The electronic nose was able to detect the onset of abiotic and biotic plant stresses. Volatile organic compounds (VOCs) emission by plants was also evaluated by head space analysis performed by gas chromatography–mass spectroscopy (GC–MS). The humidity sensor has been used also to reduce the always present effect of humidity on the metal oxide thin films. A simple correlation analysis divides the metal oxide sensors in two classes of similar characteristics, which could permit to make use of just two sensors.