Highly efficient one-step selective separation of heparin via multi-functional adsorptive membranes

•Adsorptive membrane was prepared by grafting a tunable polymer brush of APTMAC.•The membrane exhibits excellent hydrophilicity and heparin adsorption capacity.•Membrane can selectively capture heparin while recover BSA in an one-step separation.•Heparin was adsorbed via electrostatic interaction of -N(CH3)3+ groups of membrane.•The membrane can be an alternative to polycationic adsorbents for heparin separation.