纳米金-蛋白A介导抗体定向固定的压电传感及电化学特性研究

以纳米金为载体标记蛋白A(PA),用于介导抗体在压电石英晶体金电极表面的定向固定化.以补体C_1q抗体为模型,采用压电传感技术实时监察了此敏感界面的免疫反应过程,并考察了与补体C_1q免疫反应的压电响应性能.金标PA固定抗体的方法与传统的直接PA固定化方法相比较,具有传感界面无需活化,固定抗体的免疫活性高等优点,可对相应抗原进行高灵敏的压电免疫检测.分别利用循环伏安和电化学交流阻抗技术对金标PA固定抗体及其免疫反应的动力学过程进行了表征.

Piezoelectric and Electrochemical Characteristics of Oriented Antibody Immobilization Mediated by Gold Nanoparticle-labeled Protein A

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.