The novel cross-linked bovine serum albumin (BSA) composite membranes were prepared by interfacial polymerization method upon porous polycarbonate track-etched (PCTE) substrates. There was chemical cross-linking reaction between the amine groups of BSA and acyl chloride groups of trimesoyl chloride (TMC) in the water/oil interfacial zone. The composite membranes were characterized by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The influence of monomer concentration, interfacial polymerization reaction time and temperature on the properties of crosslinked BSA composite membranes was investigated in detail. The repulsive and attractive electrostatic interactions among BSA molecules in the thin films could be controlled by adjusting pH value and ionic concentration in feed solutions, so that the cross-linked BSA composite membranes possessed stimuli-responsive properties. (c) 2013 Elsevier B.V. All rights reserved.