Polymer brushes decorated reduced GO (rGO) with advanced applications have been prepared by bioinspired polydopamine (PDA) chemistry integrated with activators regenerated by electron transfer atom transfer radical polymerization (ARGET‐ATRP) technique. First, rGO/PDA was obtained by the process for graphene oxide (GO) coated with a homogeneous bio‐adhesive PDA layer. Then the initiator 2‐bromoisobutyryl bromide (BIBB) was immobilized on the surface of PDA functionalized rGO. Finally, rGO/PDA‐Br was polymerized with N, N‐diethylaminoethyl methacrylate (DEAEMA) and glycidyl methacrylate (GMA) to obtain rGO/PDA‐g‐polymer brushes by ARGET‐ATRP process. The prepared rGO/PDA‐g‐PGMA brush would be subjected to further functionalization with ethylenediamine (EDA), which would impart the obtained products (rGO/PDA‐g‐PGMA‐NH2) with good adsorption ability toward cationic dyes. The chemical structures and morphologies of the functionalized GO products have been characterized in detail by Fourier transform infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), Raman spectroscopy, thermal gravimetric analysis (TGA), scanning electron microscope (SEM), transmission electron microscope(TEM), and atomic force microscopy (AFM). The distinctive pH‐responsive character of rGO/PDA‐g‐PDEAEMA and adsorption ability of rGO/PDA‐g‐PGMA‐NH2 for cationic dyes have been explored by UV–vis spectrophotometer. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 689–698