一种基于金磁微粒的电化学发光免疫检测方法

An Electrochemiluminescence Immunoassay Based on GoldMag Particles

基于金磁微粒(GoldMag particles)的磁性分离富集性能与良好的生物相容性,直接在金磁微粒表面吸附固定相思子毒素多抗制备捕获探针,以三联吡啶钌标记相思子毒素单抗作为电化学发光探针,两者与相思子毒素发生特异性免疫反应形成夹心复合物,成功建立了一种简单、快速、灵敏的相思子毒素电化学发光免疫检测方法。利用此方法检测相思子毒素,其浓度在0.2～1 500μg/L范围内与电化学发光强度成良好的对数线性关系,检出限为0.2μg/L。与生物素-亲和素固定法相比,该法的检出限相当,其线性范围更宽、操作更简化,具有通用性,可以此为基础发展生物毒素及其它蛋白的检测方法,用于临床诊断、环境监测及生物防护等领域。

A new efficient electrochemiluminescence（ECL） immunoassay strategy was developed for the determination of abrin based on the large specific surface area and excellent biocompatibility of GoldMag particles. The assay consisted of a double antibody sandwich format in which polyclonal an tibody （PeAb） of abrin was immobilized on GoldMag particles as capture probe, and Ru （bpy） ] 32＋ -la- beled monoelonal antiboday （MeAb） for ECL probe. First, immobilized PcAb, abrin and Ru （bpy）32＋-labeled McAb formed sandwich immunoeomplex via the specific immune response. Then abrin was determined by eleetrochemiluminescenee（ECL） reaction. A logarithmic linear relationship （ r = 0. 998 4） between ECL intensity and concentration of abrin in the range of 0. 2 - 1 500 μg/L was obtained, and the detection limit was 0.2 μg/L. Compared with the biotin - avidin immobilization method, this new approach possesses more considerable sensitivity, wider linear range, more simpli- fied steps and holds a great promise in the sensitive detection of target proteins in various fields such as clinical diagnosis, environmental monitoring and biodefense