Abstract 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.