One-pot synthesis of carbon nanotube-polyaniline-gold nanoparticle and carbon nanotube-gold nanoparticle composites by using aromatic amine chemistry.

Harsh oxidative treatment of single-walled carbon nanotubes (SWNTs) was used to generate carboxyl groups on SWNT sidewalls. The oxidized SWNTs can disperse well in ethanolic solutions containing aniline (or it derivative, 4-dodecylaniline), possibly due to the formation of proton-transfer complexes between carboxyl and amine groups. Addition of HAuCl 4 into the above-mentioned solutions can readily produce SWNT-polyaniline (PANI)-Au nanoparticle (NP) or SWNT-Au NP composites in an in situ one-pot fashion. Transmission electron microscopy, UV-vis spectroscopy and cyclic voltammetry have been employed to characterize the obtained composites. Our findings suggest that the obtained composites and electrodes modified with this material may find interesting applications in electrochemical sensors and conducting polymer coatings.