A new strategy for constructing the capacitance immunosensor was developed based on gold nanoparticles, which were employed as the platform to immobilize immunospecies. Gold nanoparticles were fixed on the gold electrode, on which the oligomer layer of o-aminobenzenthiol was pre-formed via electrochemical polymerization. An interesting immunospecies was loaded on gold nanoparticles to complete the fabrication of capacitance immunosensor. The changes in morphology of the gold electrode during the experiments were revealed by atomic force microsc...