Laccase-catalyzed synthesis of optically active polyaniline

One step, simple and environmentally friendly enzymatic synthesis of optically active polyaniline in the bulk solution and on the surface of glass slides (in situ deposition) was developed. Fungal laccase from Trametes hirsuta was used as the catalyst of the oxidative polymerisation of aniline. The reaction was carried out under aerobic condition in the weak acidic aqueous solution in the presence of the chiral dopant, such as (S)- or (R)-camphorsulfonic acid. The doping/de-doping procedure of optically active polyaniline was reversible. It was shown that a chiral conformation of the polyaniline was quite variable, and the optical activity of the polymer could be changed by the replacement of camphorsulfonic acid enantiomer in the polyaniline structure.