New organic electronic organic ammonia sensors based on hybrid nanocomposites polyaniline-titanium dioxide and on PANI/chitosan with high metrological performances were created. The physical and chemical properties of the nanocomposites were optimized to get a high sensitivity and very low detection threshold (in ppb values). For hybrids, in the core shell form, the performances were analyzed by the synergetic effects of the constituents. For biopolymers it is possible to get high performances ammonia sensors using the way of green chemistry. In both cases the nanocomposites worked at room temperature and showed linear responses with a response time around one minute.
