红细胞标记抗体的电化学免疫分析

Electrochemical Immunoassay With Erythrocyte Labled Antibody

研究了红细胞标记抗体的电化学免疫分析法。用乙型肝炎单克隆抗体致敏的红细胞作双抗夹心免疫分析的酶标二抗替代物。在免疫反应完成后，结合抗原－抗体免疫复合物上的敏化红细胞在低渗溶液中溶血，释放出血红蛋白（Ｈｂ）。Ｈｂ催化底物邻苯二胺的氧化反应，产生有电活性的产物２，３－二氨基吩嗪（ＤＡＰ）。用单扫描示波极谱法检测ＤＡＰ。ＤＡＰ的极谱还原电流与被测乙型肝炎表面抗原（ＨＢｓＡｇ）浓度线性相关。本方法可检出０．５μｇ／ＬＨＢｓＡｇ，比酶联免疫吸附法（ＥＬＩＳＡ）灵敏度高１０倍。

An elctrochemical immunoassay with erythrocyte labled antibody was studied. The erythrocyte sensitized by monoclonal anti-hepatitis B surface antibody was utilized as an alternative of the second enzyme-labled antibody in double antibody sandwich immunoassay. After the sandwich immunoreaction, the sensitized erythrocyte, which combined with im- mune complex, suffers hemolysis in low osmotic solution and releases hemoglobin (Hb). Hb catalyzes the oxidation of substrate o-phenylenediamine (OPD) to generate an electroactive product 2, 3-diaminophenazine (DAP). The amount of DAP was determined by linear-sweep polarography. The polarographic reduction current of DAP was linearly related with the con- centration of hepatitis B surface antigen (HBsAg ). The assay can detect 0. 5 μg/L of HBsAg. The sensitivity of the proposed assay was 10 times higher than that of ELISA.