Fe3O4-functionalized graphene nanoribbons (Fe3O4-GNR5) were prepared in situ by a facile one-step solvothermal process. The as-prepared nanocomposites were characterized by X-ray diffraction, transmission electron microscopy, Raman spectroscopy, etc., and the results indicate that the Fe3O4 nanopartides were successfully formed on the GNRs. Furthermore, the electrochemical activity of Fe3O4-GNR5 and Fe3O4-functionalized graphene nanosheets (Fe3O4-G) was compared by employing dopamine as the redox probe, which indicated that the redox process of the probe at Fe3O4-GNRs is faster than that at the Fe3O4-G modified electrode. This study could be potentially useful for understanding the structure/property relationship of the graphene-based materials, and synthesizing advanced graphene-based materials for electrochemical applications. (C) 2013 Elsevier B.V. All rights reserved.