Prussian blue (PB) nanocrystals are decorated on the TiO2 nanotube arrays (TiNTs) by one-step photocatalytic method. The formed PB-TiNTs composite shows high electrocatalytic activities towards the reduction of H2O2. When the TiNTs layer is covered with a layer of Au nanoparticles (AuNPs) before PB decoration, the electrocatalytic activity is significantly enhanced on the as-formed PB-AuNPs/TiNTs nanocomposite, due to the synergistic effect of AuNPs and PB. Compared with PB-TiNTs, the PBAuNPs/TiNTs based electrode shows improved electrochemical behaviors for H2O2 sensing, such as low overpotential, high sensitivity, wide linear range, and decreased detection limitation, and thus provides a simple, promising and cost-effective sensing platform for development of enzyme based biosensors. (C) 2014 Elsevier Ltd. All rights reserved.