一种基于巯基化聚丙烯胺自组装膜的免疫传感器固定方法

A Novel Protein Immobilization Approach Based on Mercapto-poly(allylamine hydrochloride) Self-assembled Membrane for Piezoelectric Immunosensors

提出了一种基于巯基自组装的新型蛋白质固定化方法。应用偶联试剂碳二亚胺 (EDC)和N 羟基琥珀酰亚胺 (NHS)使聚丙烯胺盐酸盐 (PAH)与 3 巯基丙酸 (MPA)偶合 ,在石英晶振表面自组装 ,形成一带多氨基的巯基自组装膜。应用该方法成功地固定了羊抗人IgM抗体 ,并用于人血清免疫球蛋白M (IgM)的测定。详细考察了自组装条件、抗体包被和免疫反应的主要实验条件以及传感器的响应性能。与MPA法比较 ,应用该方法可在传感器表面固定更多的抗体分子 ,传感器的响应灵敏度亦更好。在优化的实验条件下 ,反应的线性范围 0 .6 6～ 2 6 .4mg L ;回归方程Y =92 .44 +12 .40X ;相关系数r=0 .992 0。

A novel protein immobilization approach for piezoelectric immunosensors has been proposed, which is based on the self-assembled membrane (SAM) of mercapto-poly (allylamine hydrochloride) (PAH) formed by coupling mercaptopropionic acid (MPA) to PAH via 1-ethyl-3-(3-dimethylamino-propl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). After self-assembling a mercapto-PAH SAM on the gold electrode of the quartz crystal, the goat-anti-IgM antibody is immobilized via cross-linking with glutaraldehyde. Comparing with the MPA SAM method, this new approach shows greater frequency response and higher sensitivity. The detecting linear range of the piezoelectric immunosensor employing mercapto-PAH SAM is 0. 66 similar to 26. 4 mg/L, and that of the immunosensor employing MPA SAM is 2.2 similar to 24.2 mg/L.