In this work, a facile, feasible and controlled electrochemical route was developed to prepare well-defined three-dimensional (3D) gold hierarchical dendrites (Au HDs) on a glassy carbon electrode by one-step electrodeposition, using the applied potential of 0.0 V for 600 s in the electrolyte containing 20 mM HAuCl4, 150 mM cytosine and 0.5 M H2SO4. Cytosine played important roles in the synthesis of the Au HDs, while no seed, template or surfactant involved. The corresponding growth mechanism was discussed in some detail. The as-prepared Au nanocrystals were applied as Raman-active substrates for surface-enhanced Raman scattering (SERS) amplification detection of Pb2+ with high sensitivity. (C) 2013 Elsevier Ltd. All rights reserved.