Highly sensitive wireless nitrogen dioxide gas sensor based on organic conductive nanocomposite paste

Hazardous gas sensor technology in a wireless system is needed urgently for diverse applications ranging from the workplace to the battlefield. However, there are several limitations of the wireless gas sensing system such as high cost and poor sensitivity and selectivity for applications in real life. Here, a radio frequency identification (RFID)-based wireless sensor system is fabricated using an organic conductive nanocomposite paste composed of multidimensional Fe2O3 hollow nanoparticles (M_FeHNPs) and polystyrene sulfonic acid-doped polyaniline (PANI:PSS). The conductive paste acts as an RFID tag antenna pattern and sensing transducer in the RFID sensor tag. This RFID-based wireless sensor shows ultrahigh sensitivity (up to 0.5 ppm) to NO2 with very low processing cost. In addition, the organic conducting paste based RFID sensor system displays a long-distance operating range and high flexibility, which may offer practical use in a wearable device for wireless sensing.