The present invention discloses a NOx sensor consisting at least of a pair of the first and the second electrodes formed in touch with an ion conductive solid electrolyte; wherein at least the first electrode is selected from hybrid oxides having perovskite structure expressed by MSnO.sub.3 (M is at...http://www.google.es/patents/US5897759?utm_source=gb-gplus-sharePatente US5897759 - NO.sub.x sensor
