The growing concerns about the impact of the harmful gas emissions on the human health and the environment, as pointed out by the World Health Organization reports , has stimulated the research for solid-state gas sensing devices with better sensitivity and low production costs. Thus, new systems are searched for being sensitive in detecting ppm or ppb concentrations of flammable (H2, ethanol, hydrocarbons) and toxic (H2S, CO, NO2) gases. Additionally, they also must present selectivity in the presence of interferent gases , and be able to operate at temperatures closer to environmental conditions. Recently, it has been shown that the increased concentration of NO2 may have some influence on SARS-CoV-2 infections . Such facts highlight the urgency of developing new sensors that are simple and affordable for monitoring.