Abstract: Firstly,o-phenylenediamine(OPD) was electropolymerized on carbon paste electrode（CPE/POPD）by cyclic voltammetry method.Then the gold nanoparticals (GNPs) and prussian blue (PB) were deposited onto the CPE/POPD by electrodeposition technology to fabricate CPE/POPD/PB-GNPs electrode.Finally,the goat anti-mouse IgG (antibody,Ab) were immobilizeded on to the CPE/POPD/PB-GNPs electrode through Au-NH-bond,and thus a potentiometric immunosensor (CPE/POPD/PB-GNPs/Ab) was sucessfully prepared.The modified process of the electrode was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS).The immunosensor exhibited fast potentiometric response (<3 min) under the antigen concentration of 2.0×10-5 μg/L and 1.0×104 μg/L when it was used to detect the mouse IgG.The results of experiments showed that the immunosensor based on POPD/GNPs-PB composite film exhibited the advantages of high sensitivity,fast response,wide detection range and low cost.

Key words: poly (o-phenylenediamine), nano gold, prussian blue, antibody