A　nonenzymatic　electrochemical　method　was　developed　for　hydrogen　peroxide　(H2O2)　detection　using　an　electrode　modified　with　palladium　nanoparticles　(PdNPs)-graphene　nanosheets　(PdNPGNs).　Ultrafine　PdNPs　were　homogeneously　modified　on　graphene　nanosheets　through　a　facile　spontaneous　redox　reaction　and　characterized　by　transmission　electron　microscopy,　energy-dispersive　X-ray　spectroscopy　and　X-ray　photoelectron　spectroscopy　technique.　Based　on　the　voltammetric　and　amperometric　results,　the　PdNPGNs-modified　glassy　carbon　electrode　(PdNPGNs-GCE)　demonstrated　direct　and　mediatorless　responses　to　H2O2　at　a　low　potential.　The　analytical　performances　of　the　PdNPGNs-GCE　toward　H2O2　reduction　was　evaluated　in　the　linear　response　range　from　0.1　mu　M　to　1.0　mM,　with　a　detection　limit　(S/N　=　3)　of　0.05　mu　M.　The　PdNPGNs-GCE　showed　excellent　resistance　toward　poisoning　from　such　interfering　species　as　ascorbic　acid,　dopamine　and　glucose.　Furthermore,　the　electrochemical　sensor　presented　good　characteristics　in　terms　of　stability　and　reproducibility,　promising　the　applicability　of　this　sensor　in　practical　analysis.　(C)　2013　Elsevier　Ltd.　All　rights　reserved.