Polyaniline grafted reduced graphene oxide (RGO-g-PANI) composites were synthesized via a facile and efficient two-step method. RGO was first surface-modified with 1,3-diaminopropane, which provided reactive NH2 groups that can polymerize with aniline, and then grafted with polymer chains. The analysis results showed that the surface of the RGO sheets was covered with a smooth thin layer of polyaniline. The as-prepared composites were used to modify the glass carbon electrodes for the chemical detection of hydrogen peroxide in aqueous solutions. The response to H2O2 was linear in the range, 0.05 to 14 mu M (R-2 = 0.995), and the detection limit was 0.37 mu M (at an S/N of 3). In addition, the specific capacitance of the obtained composite was as high as 1337 F g(-1) at a very high current density of 15 A g(-1), highlighting its promising applications as an efficient electrode material for supercapacitors. (C) 2015 Elsevier B.V. All rights reserved.