Many fields of life require fast, cheap and reliable gas sensors. The development of these sensors still belongs among actual problems. There are currently several different kinds of AZD-9291 device, each employing different operational features. For the detection of NO2 we may mention, e.g., chemiresistive , potentiometric , amperometric , gravimetric , electrical and optical  sensors. The promising nowadays seemed to be chemiresistive type of sensors. They are exceptionally simple in preparation and usage. However, they suffered lack of selectivity, which was usually overcome using arrays of different sensing elements , ,  and . The second problem represents long term stability. Solid NO2 sensors based on inorganic materials very often operate at high temperature  and , which limits their applications. Therefore, great attention was paid to reducing the operating temperature . Sensors based on organic sensing layers partly overcome this problem. However, NO2 is strong acceptor and, therefore, sensitive layers can be non-reversibly destroyed  and  which influences sorption/desorption process and its kinetics and stability of baseline. A typical example are sensors based on phthalocyanine films , even that these molecules are generally very stable.