Magnetic nanocomposites rich in amino and carboxyl groups were synthesized by the cross-linking of ferrocene acid and chitosan through EDC/NHS and the addition of iron oxide nanoparticles.This nanocomposite modified gold electrode adsorbed gold nanoparticles and anti-AFP antibody through amino group and electrostatic interaction,which constructed highly sensitive amperometric AFP immunosensor. The electrochemical characteristics of the electrode were investigated by cyclic voltammetry. The effect of incubat...