▎ 摘　　要

A facile and effective method was introduced for the controlled synthesis of dendritic gold nanostructures on the electrode via a simple electrochemical route in which graphene oxide (GO) was used as a morphologycontrolling agent. The oxygencontaining groups on GO controlled not only the diffusion of AuCl4- ions but the subsequent generation of gold nuclei at the initial stage and the growth direction of the gold nanocrystals in the electrochemical synthesis process. The morphologydependent electrochemical sensing ability of gold nanostructures was discussed in detail on the basis of control experiments related to the concentration of GO, HAuCl4, and the electrodeposition time. It could be a straightforward and controllable method for improving the nanoparticles' electrochemical performance. The unique nanostructure and excellent electrocatalytic properties of the dendritic gold nanostructures made the modified electrode an excellent choice for differential pulse voltammetric determination of Fe(III). The modified electrode exhibited a linear response to Fe(III) in the 7 nM to 1 mM concentration range, with a lower detection limit of 1.5 nM. The modified electrode was successfully applied to the sensitive determination of iron in local coastal waters.