The nanostructured composite material, which is based on doped polyaniline (PANI) and thiol functionalized gold nanoparticles (AuNPs), has been prepared by an osmosis-based method. Several morphologies were obtained, ranging from amorphous to sponge-like or spherical shapes.

After investigating the structures, different materials with high surface area were selected and tested as chemical interactive materials for room temperature gas and vapour sensing. In the study, the resistive sensor devices were exposed to a range of compounds of interest both in the field of environmental monitoring and for biomedical applications. Test vapours included toluene, acetic acid, ethanol, methanol, acetonitrile, water, ammonia and nitrogen dioxide.

After H2SO4 doping, nanoPANI–Au samples showed a higher response to ammonia vapor in low concentration (10.8 ppm) at room temperature.

The facile preparation method and the improved properties of the polyaniline-gold composite material are promising features for application of this material in ammonia vapor monitoring.

The researchers presented their results in the journal Nanotechnology.