基于巯基自组装单层膜的日本血吸虫石英晶体微天平免疫传感器

摘要

应用自组装膜技术在压电石英晶振金电极表面自组装一带羧基的巯基丙酸单层膜, 通过盐酸1-乙基-3-(3-二甲基氨基丙基)碳二亚胺及N-羟基琥珀酰亚胺共价固定32KD的日本血吸虫分子抗原(SjAg32), 设计了石英晶振微天平免疫传感器, 用于测定日本血吸虫抗体. 比较了巯基自组装单层膜与HEMA-MMA共聚物涂层修饰的石英晶振在溶液中的振荡行为, 发现巯基自组装单层膜修饰的石英晶振稳定快, 且稳定性好. 在优化条件下, 测得IRS(49-2000)的滴度为1∶1 500. 此外, 对不同程度血吸虫感染的兔血清进行了测试, 结果表明，该传感器能较好地定量区别血吸虫感染程度.%A quartz crystal microbalance(QCM) immunosensor has been developed for the direct determination of schistosoma-japonicum-infected rabbit serum(Sj-IRS). Self-assembled monolayers(SAMs) with carboxyl groups were first coated on the gold electrodes of the quartz crystal resonators by spontaneous adsorption of mercaptopropionic acid(MPA). Schistosoma-japonicum molecular antigen of 32 kD molecular weight(SjAg32) was then covalently attached to the crystal surface via EDC and NHS. The results show that the SAM-coated quartz crystal has a better oscillating behavior in aqueous solutions than ordinary polymer-coated quartz crystal. The QCM immunosensor was used for the detection of infected rabbit serum(IRS49-2000), and a maximum titer of 1∶1 500 was achieved. Finally, several rabbit serum samples with different degrees of infection were tested. The results show that the QCM immunosensor is suitable for detecting the infection degree of IRS.