In-situ decorated gold nanoparticles on polyaniline with enhanced electrocatalysis toward dopamine

Gold nanoparticles were in-situ decorated on top of a polyaniline film (GNPs-PANI) via the direct electro-reduction of the adsorbed AuCl4- ions on a glassy carbon electrode that previously was coated with PANI by electropolymerization. The GNPs-PANI composite and the performance of the resultant sensors were investigated in some detail. The sensor was applied to the oxidation of dopamine (DA) with improved catalytic activity. Its catalytic current showed wide linear response toward dopamine ranging from 3 to 115 mu M, with a low detection limit of 0.8 mu M (S/N=3). In addition, the sensor exhibits easy-operation, fast response to dopamine, as well as excellent reproducibility and stability.