Abstract: Anovel method based on plasma-polymerized films(PPFs) is proposed for immobilization of antibodies(antigens). PPFs are prepared on the surfaces of base sensors by a ratio frequency plasma method with n-butyl amine as a plasma source, and the IR spectrum indicates the existence of amino group in the film. Apolyanion layer is then self-assembled on the film through strong electrostatic attraction. Subsequently, antibodies(antigens) are immobilized on the self-assembled layer through controlling the pHvalue of immobilizing solution. The immobilization of goat-anti-IgG antibody, as an example, on the surfaces of quartz crystal microbalance (QCM) is investigated. After depositing a n-butyl amine PPFon the surface of QCM, a polystyrenesulfonate (PSS) layer is self assembled on the PPFfrom a 2.0 mg/mLof PSSsolution in 0.05 mol/L HCl. The goat anti IgGantibody is then immobilized in antibody immobolizing solution(0.2 mg/mL goat-anti-IgGantibody, pH5.0). This immobilization shows a better frequency response than the covalent immobilization with glutaraldehyde. The QCM immunosensor can quantitatively be used to determine NHIgG in the range of 0.7～126μg·mL^-1, and shows a good reproducibility. Moreover, the immunosensor can be easily regenerated by using a pHshift.

Key words: Plasma-Polymerized film, Immunosensor, Polyelectrolyte, Immobilization