Carbon nanotube/polypyrrole/antibodies polymer films were synthesized successfully on microelectrodes by electrochemical deposition. Electropolymerization was performed at optimal range between -0.8 and +0.8 V at a scan rate of 50 mV s(-1) in an electrochemical mini-cell containing monomer pyrroles, carbon nanotubes, and goat IgGs. The conducting polymer films were characterized by Fourier transform infrared spectrometry, Raman spectra, and Field emission scanning electron microscopy. And then, it was prepared for immunosensor application to determine anti-goat IgGs. The results show that a linear range between 0.05 and 0.7 mu g ml(-1) for anti-goat IgGs detection was observed for immunosensor, a detection limit as low as 0.05 mu g ml(-1) and a response time of 1 min. The effect parameters of electropolymerization process on immunosensor response are also studied. It found that the immunosensor well active in 1.5 mg ml(-1) CNT concentration, 2.5 mM pyrrole, 10 mu g ml(-1) goat IgGs. (C) 2011 Elsevier B. V. All rights reserved.