Detection of H2O2 is very important in biological analysis, clinical diagnosis, food industry, etc. This work presents an electrochemical approach for the detection of H2O2 based on Prussian blue (PB) nanocubes-nitrobenzene-reduced graphene oxide (RGO) nanocomposites (PB nanocubes-nitrobenzene-RGO). The hybrid nanocomposites were constructed by growing PB nanocubes onto the nitrobenzene-RGO composites which were prepared by spontaneous grafting nitrophenyl groups to the basal carbon atoms of RGO based on chemical bonding. The obtained PB nanocubes-nitrobenzene-RGO nanocomposites were characterized by scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. The formation mechanism of PB nanocubes-nitrobenzene-RGO nanocomposites was investigated and discussed in detail. The PB nanocubes-nitrobenzene-RGO modified glassy carbon electrode shows good electrocatalysis toward the reduction of H2O2. The resulted H2O2 biosensor exhibited a rapid response of 2 s, a low detection limit of 0.4 mu M, a wide linear range of 1.2 mu M to 15.25 mM and high sensitivity of 300.16 mu A cm(-2) mM(-1), as well as good stability, repeatability and selectivity. Further immobilizing glucose oxidase on the PB nanocubes-nitrobenzene-RGO nanocomposites/GCE, an amperometric glucose biosensor was achieved by monitoring the generated H2O2 under a relatively negative potential. The sensors might be used as a promising one for practical application. (C) 2013 Elsevier Ltd. All rights reserved.