基于电聚合膜和纳米金自组装的生物分子固定化新方法的研究

A Novel Method for Biomolecule Immobilization Based on Electropolymerized Films and Self-assembled Nano Gold

结合电聚合膜和纳米金自组装技术,提出了一种新的生物分子固定化方法,研制成一种检测抗胰蛋白酶的压电免疫传感器。通过在石英晶振金电极表面电聚合邻苯二胺膜,再在膜表面自组装一层纳米金粒,以静电吸附作用固定抗体(抗原),实现对相应抗原(抗体)的检测。利用扫描电镜技术,从形态上考察了晶振金电极上自组装纳米金后的表面形貌。研究了抗体的固定化条件,探讨了传感器的响应与再生性能。结果表明,这种固定化方法对所固定的生物分子的生物活性影响小,传感器的测定灵敏度高,响应性能和再生性能较好。

In this paper,a novel method for biomolecule immobilization is proposed based on the combinaˉtion of electropolymerized films(Eps)and self_assembled nanostructures.The method was applied to the development of an immunosensor for antitrypsin(α 1 -AT)detection in human serum.An electropolymerˉized o_ phenylenediamine film was immobilized on the surface of a quartz _ crystal microbalance(QCM).Then a self_assembled nano_gold layer was applied on the electropolymerized film.Finally the antibodies of the antitrypsin(Anti_α 1 -AT)were electrostatically adsorbed onto the QCMsurface for the detection of antitrypsin via immunoreaction.The surface morphologyof the QCMwas studied with scanningelectron miˉcroscopy(SEM)after nano_gold modification.The antibody immobilization conditions have been investigatˉed in details.As compared to the glutaraldehyde binding procedure,the nano_gold self_assembly proceˉdure provides higher antibody activity and larger frequency response to immunoreactions.It is concluded that this immunosensor has the advantages of higher sensitivity,improved selectivity and better regeneraˉtion performance.