四羧基酞菁钴Ⅲ/Fe_3O_4/金胶共固定修饰免疫传感器检测尿样中核基质蛋白22

Electrochemical Immuno-Biosensor for Nuclear Matrix Protein 22 in Urine Samples by CoⅢ Phthlocyanine/Fe _3O_4/Au Collide Coimmobilized Electrode

同时固定四羧基酞菁钻（Ⅲ）（CoPc）和HRP标记核基质蛋白22抗体（HRP-Ab-NMP22）于自组装在金电极表面的Fe3O4／Au胶上，构建了一种快速测定膀胱肿瘤患者尿液中NMP22抗原（NMP22）含量的安培免疫传感器。CoPc可被用作电檄表面HRP的电子传递媒介体。当该传感器在含NMP22尿样的溶液中温育后，NMP22与HRP-Ab-NMP22免疫结合导致HRP的活性中心与CoPc之间的电子传递部分阻碍，使HRP对H202电催化还原电流Io，降低。△Io与NMP22浓度在1．2～200μg／L呈线性关系；检出限为0．5μg／L。该传感器对NMP22响应灵敏，较ELISA法提高了检测速度，有望用于膀胱肿瘤的体外诊断。

A novel immunosensor was proposed for the rapid determination without separation of nuclear matrix protein 22 （NMP22） antigen in human urine . The immunosensor was prepared by co-immobilizing hoseradish peroxidase （HRP）-NMP22 antibody, Co（Ⅲ） phthalocyanine （CoPc） on a Fe3O4/Au collide -modified gold electrode （HRP-Ab-NMP22/ Fe3O4/Au colloid/CoPc CME） using the self-assembly technique in which CoPc was as electron immediate. The modified electrode shows an excellent electrocatalytic activity for NMP22 antigen in phosphate buffer solution （ pH 7.0）. After the immunosensor is incubated with NMP22 antigen solution at 37℃ for 20 min, the access of activity center of the HRP to electrode is partly inhibited, which leads to a linear decrease of the catalytic efficiency of the HRP to the reduction of immobilized CoPc by H2O2 at -50 mV in NMP22 antigen concentration ranges from 1.2 to 200 μg/L. The detection limit was 0.5 μg/L. The immunosensor was successfully utilized for the determination of NMP22 antigen in urine samples of bladder patients, which shows a good accuracy, precision and reproducibility. This method decreases the detection cost and shortens the analytical time, thus would be valuable for clinical immunoassay for bladder cancer.