In this article, poly[(dimethylamino) ethyl methacrylate] (PDMAEMA) brushes were grafted onto graphene oxide (GO) sheet via noncovalent modification of pyrene terminated initiator and subsequent in situ surface-initiated atom transfer radical polymerization (SI-ATRP). The results of zeta-potentials, dispersivity measurement as well as the permeability of cationic and anionic redox-active probe molecules reveal that the as-prepared GO/PDMAEMA composite exhibits zwitterionicity because of the presence of phenol hydroxyl, carboxyl, and amine groups and the charging state can be manipulated by controlling pH values. Furthermore, by ion exchange and in situ reduction, palladium and gold nanoparticles were successfully uploaded and the catalytic property of the uniformly distributed Pd-Au nanoparticles on GO sheet was investigated. These results reported in this work may open primarily toward constructing a bridge among GO, charged polymer and metal nanoparticles and secondarily to represent a new strategy for uniformly depositing inorganic nanoparticles. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 127: 3074-3083, 2013