Using poly-(epichlorohydrin) and 4-pyridinecarboxaldehyde, we synthesized a new aldehyde-functionalized polymer, which was applied to simplify antibody immobilization on the electrode surface, in which no additional chemical cross-linking is required. Combined with the advantages of graphene, a label-free electrochemical immunosensor based on graphene/aldehyde-containing polymer film for alpha-fetoprotein detection was fabricated. alpha-Fetoprotein was detected within the range from 0.05 to 35 ng mL(-1) with a detection limit of 0.02 ng mL(-1) obtained by 3 S/N. The proposed immunosensor is easy, label-free, specific and thus provides a good diagnostic tool for detection of alpha-fetoprotein and other cancer markers. (C) 2015 Published by Elsevier B.V.