Room Temperature Operated PEDOT: PSS Based Flexible and Disposable NO₂ Gas Sensor

This work presents a flexible and disposable nitrogen dioxide (NO ₂ ) gas sensor based on Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), operating at room temperature (RT). The gas sensing layer, composed of PEDOT:PSS, is deposited on interdigitated electrodes (IDEs) made from graphene–carbon ink, which are screen printed onto a paper substrate using the drop casting method. The Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses are carried out to understand the successful deposition and surface morphology analysis of the sensing layer. The NO ₂ sensing properties are explored in the range 0.5–50 ppm at RT (27 °C ± 2 °C). The sensor displays significant % response viz., 0.79%–12.97% in the measured range 0.5–50 ppm. Other important sensing characteristics, such as response and recovery times (210 s / 60 s at 0.5 ppm), repeatability, and reproducibility along with sensing mechanism are also presented. The findings of this letter suggest that the developed sensor holds promise for various application areas.