▎ 摘　　要

Herein Pd/Fe3O4-PEI-RGO nanohybrid was synthesized by dispersion of Pd NPs and Fe3O4 NPs on PEI modified graphene oxide sheets. This nanohybrid was found to possess superior peroxidase-like activity, and could efficiently oxidize 3,3',5,5'-Tetramethylbenzidine (TMB) by hydrogen peroxide (H2O2) to produce a color reaction. Therefore, this provides a sensing platform for the colorimetric detection of H2O2 in solution. The linear range for H2O2 was from 0.5 to 150 mu M and the limit of detection was as low as 0.1 mu M. Moreover, the nanohybrids have the advantages of facile preservation and rapid separation. More importantly, comparing with the other catalysts (PEI-RGO, Fe3O4-PEI-RGO and Pd-PEI-RGO), this nanohybrid exhibits the enhanced peroxidase catalytic activity. Thus, it is expected that this nanohybrid could conveniently and efficiently detect H2O2 in the pharmaceutical, environmental and industrial fields. (C) 2015 Elsevier Ltd. All rights reserved.