Highly stable polyaniline-poly(sodium 4-styrenesulfonate) nanoparticles for sensing of amines.

Sensing technology is the key of intelligent packaging. A variety of different sensing systems for indicating freshness through intelligent packaging have been presented. Polyaniline (PANI) can change its color reversibly through the acid-base reaction with reactive compounds and has been widely used in different kinds of sensors. However, because PANI is insoluble in common organic solvents, this limits its practical usage in many applications. In this work, a highly stable polyaniline-poly(sodium 4-styrenesulfonate) (PANI:PSS) colloid has been developed as a facile colorimetric sensor of volatile amines. The results showed the PANI:PSS colloid is quite sensitive to changes in pH. When PANI:PSS colloids were homogenously deposited on filter paper, the paper are used as a sensor to detect triethylamine (TEA) vapor. The green color of the test paper changed to blue at a TEA concentration as low as 188 ppm.