本文构建了一种基于酶聚合体信号放大的多通道电化学免疫传感体系，并用于肝癌肿瘤标记物甲胎蛋白（AFP）的定量检测. 该传感体系由固定了抗AFP鼠单克隆抗体的多通道丝网印刷电极组成，可捕获肿瘤标记物抗原AFP，进而与抗AFP兔多抗特异性结合形成夹心免疫复合物，然后利用辣根过氧化物酶聚合体偶联的羊抗兔二抗（IgG-polyHRP）与三明治夹心免疫复合物结合，实现电流信号放大. 该体系结合多通道丝网印刷电极及自主研发的多通道电化学检测仪，可同时满足多通道电流信号的检测. 在最优化条件下，该传感体系检测AFP浓度的动态范围为64 pg·mL-1 ~ 250 ng·mL-1，最低检测下限为56 pg·mL-1，具有检测灵敏度高、特异性强、操作简便以及仪器便携等优点.
We have developed a multi-channel electrochemical immunosensing system for the detection of α-fetoprotein (AFP). The sensing system consisted of carbon screen-printed electrode (SPCE) arrays and polyHRP-based signal amplification probes. AFP antigens could bind to both capture antibodies immobilized on electrode arrays ant detection antibodies (anti-AFP IgG developed in rabbit). The anti-rabbit IgG conjugated to poly-horseradish peroxidase were used as a signaling probe to bind to the immuno-complex. The current signals were harvested by a home-made multi-channels electrochemical detector. AFP could be detected in the concentration ranges of 64 pg·mL-1 ~ 250 ng·mL-1. The detection limit was as low as 56 pg·mL-1. The proposed immunosensing system provided a high sensitive, specific, simple and practical method for AFP detection.
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