Sub-ppm NO2 Detection through Chipless RFID Sensor Functionalized with Reduced SnO2

NO2 is an important environmental pollutant and is harmful to human health even at very low concentrations. In this paper, we propose a novel chipless RFID sensor able to work at room temperature and to detect sub-ppm concentration of NO2 in the environment. The sensor is made of a metallic resonator covered with NO2-sensitive tin oxide and works by monitoring both the frequency and the intensity of the output signal. The experimental measurements show a fast response (a few minutes) but a very slow recovery. The sensor could therefore be used for non-continuous threshold monitoring. However, we also demonstrated that the recovery can be strongly accelerated upon exposure to a UV source. This opens the way to the reuse of the sensor, which can be easily regenerated after prolonged exposure and recycled several times.

Automated summary

In this paper, a novel chipless RFID sensor is proposed to detect sub-ppm concentration of NO2 in the environment at room temperature. The sensor is made of a metallic resonator covered with NO2-sensitive tin oxide and monitors both the frequency and intensity of the output signal. The experimental results show a fast response but slow recovery, which indicates the potential use of the sensor for non-continuous threshold monitoring. However, it is also demonstrated that the recovery can be accelerated by exposure to a UV source, enabling the sensor to be easily regenerated and recycled.