Neuron-like gold-palladium (AuPd) alloy nanostructures were synthesized by simultaneous reduction of AuCl4- and PdCl42- with ascorbic acid, using N-methylimidazole as the structure-director and stabilizing agent. The synthesis method was simple and seedless, without any template or polymer. The architectures strongly depended on the concentration of N-methylimidazole, reaction temperature and time, and hence the formation mechanism was described in detail. The as-obtained architectures exhibited superior electrocatalytic activity for ethanol oxidation and surface-enhanced Raman scattering (SERS) responses, owing to their unique nanostructures with high density of steps, edges, and corners on their branches, along with the synergetic functions between Au and Pd. (C) 2016 Elsevier Inc. All rights reserved.