It is well known that in gas sensing devices, when operated close to the ambient temperature, the sensitivity is based on physisorption mechanisms . Therefore, this remarkable response signal at 30 °C must be associated with the surface affinity of tin dichalcogenides with respect to NO2 . Conversely, the recovery kinetics are slower due to the reduced desorption rates on the surface, especially at high concentration of NO2 . This also would explain the lower signal response at 50 °C compared to 30 °C at all concentration levels, as seen in As previously discussed (Fig. and The lower detection limit (LDL) was estimated according to eq.1 ,