关键词: 纳米金, 抗体固定化, 石英晶体微天平, 循环伏安, 电化学阻抗谱

Abstract: Mediated by gold nanoparticle-labeled protein A(Nanogold-PA), the oriented immobilization of antibodies on the surface of the quartz crystal microbalance(QCM) was carried out by using C_ 1q antibody as a model test system. The immunoreaction process and piezo-response features of the created immunological interface were real-time monitored by using the QCM. It is found that the developed Nanogold-PA immobilization procedure has some advantages over the traditional direct protein A binding procedure, including activation-free for sensing interface, high immunoactivity of bound antibodies and high sensitivity for the corresponding antigens. Moreover, the kinetic characterizations of cyclic voltammograms and electrochemical impedance spectroscopy were performed. The experimental results indicate that the proposed Nanogold-PA immobilization procedure may be popularized as a general alternative method of designing various immunosensing platforms.

Key words: Gold nanoparticles, Antibody immobilization, Quartz crystal microbalance, Cyclic voltammograms, Electrochemical impedance spectroscopy