An electrochemical method for depositing redispersible, lower size gold nanoparticles from a novel polyelectrolyte-gold complex is described. The size of gold nanoparticles is in the range 6.215.4 nm. The gold nanoparticles, first deposited on platinum surface are transferable into water. They can also be directly in situ-electrodeposited on to materials like carbon, carbon nanotubes or conducting polymers for an end use as electro catalysts. The composites Au-MWCNT, Pt-MWCNT, Au-Carbon, and Pt-Carbon are synthesized and tested for their electrocatalytic activity. The composites exhibit good catalytic activity in sensing dopamine or electrooxidation of methanol. (c) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011