Department of Analytical Chemistry, Faculty of Chemistry, University Complutense of Madrid, 28040 Madrid, Spain.
Department of Analytical Chemistry, Faculty of Chemistry, University Complutense of Madrid, 28040 Madrid, Spain.
Biosens Bioelectron. 2012 May 15;35(1):82-86. doi: 10.1016/j.bios.2012.02.015. Epub 2012 Feb 17.
This work reports for the first time an electrochemical immunosensor for the determination of adrenocorticotropin hormone (ACTH). The immunoelectrode design involves the use of amino phenylboronic acid for the oriented immobilization of anti-ACTH antibodies onto screen-printed carbon modified electrode surfaces. A competitive immunoassay between the antigen and the biotinylated hormone for the binding sites of the immobilized antibody was performed. The electroanalytical response was generated by using alkaline phosphatase-labelled streptavidin and 1-naphtyl phosphate as the enzyme substrate. The electrochemical oxidation of the enzyme reaction product, 1-naphtol, measured by differential pulse voltammetry was employed to monitor the affinity reaction. Under the optimized working conditions, an extremely low detection limit of 18 pg/L was obtained. Cross-reactivity was evaluated against other hormones (cortisol, estradiol, testosterone, progesterone, hGH and prolactin) and the obtained results demonstrated an excellent selectivity. The developed immunosensor was applied to a human serum sample containing a certified amount of ACTH with good results.
本工作首次报道了一种用于测定促肾上腺皮质激素（ACTH）的电化学免疫传感器。免疫电极的设计涉及使用氨基苯硼酸将抗-ACTH 抗体定向固定在丝网印刷碳修饰电极表面上。在固定化抗体的结合位点上进行抗原和生物素化激素之间的竞争性免疫分析。通过使用碱性磷酸酶标记的链霉亲和素和 1-萘基磷酸作为酶底物来产生电分析响应。通过差分脉冲伏安法测量酶反应产物 1-萘酚的电化学氧化来监测亲和反应。在优化的工作条件下，获得了低至 18 pg/L 的极低检测限。对其他激素（皮质醇、雌二醇、睾酮、孕酮、hGH 和催乳素）进行了交叉反应性评估，所得结果表明具有极好的选择性。该开发的免疫传感器已应用于含有认证量 ACTH 的人血清样品，结果良好。
