Abstract: A novel method based on electropolymerized films(Eps) is proposed for immobilizing antibodies(antigens) through a polyelectrolyte mediated layer. The o phenylenediamine Eps are deposited on the surfaces of quartz crystal microbalance(QCM) with an electropolymerized method using o phenylenediamine as the precursor. After self assembling a polystyrenesulfonate(PSS) layer on the Eps, the immobilization of goat anti IgG antibody, as an example, is investigated. The effects of experimental conditions about PSS self assembly, IgG antibody immobilization and immunoreaction et al. on the performances of immunosensor were discussed respectively. The QCM immunosensor can be used to quantitatively determine NHIgG in the range of 1.67-196.08 μg/mL. Moreover, the PSS and protein layer can easily be removed by shifting the pH, making the immunosensor regenerable.

Key words: o Phenylenediamine electropolymerized films, PSS polyanion film, Self assembly, Piezoelectric immunosensors