基于巯基自组装单层膜技术的补体C3压电免疫传感器的研究

本文采用自组装单层膜(SAMs)技术在压电石英晶振金电极表面组装巯基丙酸SAMs,以盐酸1-乙基-3-(3-二甲基氨基丙基)碳二亚胺(EDC)和N-羟基琥珀酰亚胺(NHS)作偶联剂共价固定补体C3抗体,研制了一种检测人血清中补体C3成分的压电免疫传感器。研究了巯基丙酸的自组装和抗体的固定化条件,考察了晶振固定抗体后的液相振荡行为和检测特性。并利用压电传感装置的实时监测功能,研究了巯基丙酸在金电极表面的自组装成膜过程和补体C3免疫反应动力学,获得了重要的动力学依据和参数。传感器检测补体C3的线性范围为2．34～23．2μg／mL。将传感器用于临床样品的检测,所得结果与酶联免疫吸附法基本一致。     

A reusable piezo-immunosensor with amplified sensitivity for ceruloplasmin based on plasma-polymerized film

A reusable piezoelectric immunosensor with amplified sensitivity has been developed for the detection of ceruloplasmin (CP) in human serum. The quartz crystal microbalance (QCM) was deposited with plasma-polymerized n-butyl amine film with the surface topology further characterized by using atomic force microscopy (AFM). Anti-ceruloplasmin antibody (CP-Ab) was electrostatically adsorbed on the PPF-modified crystal via an oppositely charged polyelectrolyte layer of alginate. It was found that the alginate-mediated immobilization interface could allow for antibodies to be largely immobilized with well-retained immunoactivity. In particular, a simple regeneration process for the sensor produced, i.e. by shifting the pH, can also be realized. Moreover, an optimized assay medium containing polyethylene glycol (PEG) was tested with enhanced immunosensing response (sensitivity). A dynamic concentration range of two orders of magnitude and a detection limit of 0.15 μg ml⁻¹ of CP were observed. Analytical results of clinical samples show that the developed immunoassay is comparable with the enzyme-linked immunosorbent assay (ELISA) method. However, it presents some superior advantages over the traditional sandwich format in that the analyzing performances are direct, rapid and simple without multiple separation and labeling steps.