We report on the fabrication of hybrid films of gold nanoparticles (AuNPs) and [tetrakis (N-methylpyridyl) porphyrinato] cobalt (CoTMPyP) based on electrostatic layer-by-layer (LBL) self-assembly technique. A three-dimensional nanostructured film composed of positively charged CoTMPyP and negatively charged poly(acrylic acid)-stabilized AuNPs can be formed onto various substrates, including 4-aminobenzoic acid modified glassy carbon electrode, 11-mercaptotroponic acid modified gold film, and quartz plate with negatively charged surface. The regular growth of hybrid films is investigated by UV-vis spectroscopy, surface plasma resonance, and impedance spectroscopy. The prepared multilayer films possess flexible electro-catalytic activity toward O-2 reduction reaction. It is noted that the electro-catalytic capability of the prepared multilayer film decreases as bilayer number increases. The unexpected observation of catalytic activity with bilayer number is investigated in detail. (C) 2013 Elsevier B.V. All rights reserved.