Molecular investigation of interplay mechanism between polydopamine and graphene oxide: The effect of oxidation degree on the adsorption behavior of polydopamine

•Molecular dynamics models for polydopamine-graphene oxide interfacial behaviors.•Resonance effect of substituents in polydopamine-graphene oxide adsorption process.•Increasing oxidation degree of polydopamine avails its adsorption on graphene oxide.•Hydrogen bonding and hydrophobic effect are crucial driving force for adsorption.•Polydopamine oligomers self-assembling on graphene oxide were emphatically described.