Poly(pyrrole-3-carboxylic acid)-alumina composite membrane for affinity adsorption of bilirubin

Poly(pyrrole-3-carboxylic acid)–alumina composite membrane was prepared by polymerizing pyrrole-3-carboxylic acid onto the alumina membrane through vapor deposition polymerization method. The obtained composite membrane exhibited excellent uniformities, high density of reactive groups, and low nonspecific adsorption. Lysine as ligand was immobilized onto the poly(pyrrole-3-carboxylic acid)–alumina composite membrane by activating with N-hydroxysuccinimide and 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide. The content of lysine of lysine-immobilized affinity membranes was ∼8.9 mg/g membrane. Bilirubin adsorption was investigated in static and dynamic experiments. The adsorption capacity was related to the bilirubin concentration, temperature, ionic strength, and albumin concentration. The result of dynamic adsorption experiment showed lysine-immobilized affinity membranes can well remove the bilirubin from the bilirubin–albumin solution.