Carcinoembryonic antigen (CEA) is a member of a family of cell surface glycoproteins. Recognition of CEA is needed to monitor the physiological status of the patient for treatment and also it is important to assess the severity of the disease. In this work, we reported a novel sandwich‐type electrochemical immunosensor based on gold nanoparticles functionalized cysteamine‐glutaraldehyde (AuNPs‐CysA‐GA) and it successfully designed to detection of the CEA biomarker in a human plasma sample. The AuNPs‐CysA‐GA provides a large surface area for the effective immobilization of CEA antibody, as well as it ascertains the bioactivity and stability of immobilized CEA antigens. Biotinylated‐anti‐CEA antibody (Ab1) was immobilized on the surface of glassy carbon electrode (GCE) modified AuNPs‐CysA‐GA. Also, secondary antibody (HRP‐Ab2) was costed immobilized to complete the sandwich part of immunosensor. Field emission scanning electron microscope (FE‐SEM and EDS), was employed to monitor the sensor fabrication procedure. The immunosensor was used for the detection of CEA using differential pulse voltammetry (DPVs) technique. The proposed interface led to enhancement of accessible surface area for immobilizing high amount of anti‐CEA antibody, increasing electrical conductivity, boosting stability, and biocompatibility. Finally, the low limit of quantitation (LLOQ) of the proposed immunosensor was obtained as 7 ng/mL with the linear range of 0.001‐5 μg/L. The proposed immunoassay was successfully applied for the monitoring of the CEA in unprocessed human plasma samples. Obtained results paved that the proposed bioassay can be used as a novel bioassay for the clinical diagnosis of cancer based on CEA monitoring.

中文翻译：

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一种使用聚合物界面和免疫传感方法监测人体生物体液中癌胚抗原的新型生物测定法。

癌胚抗原 (CEA) 是细胞表面糖蛋白家族的成员。需要识别 CEA 以监测患者的生理状态以进行治疗，并且评估疾病的严重程度也很重要。在这项工作中，我们报道了一种基于金纳米颗粒功能化半胱胺-戊二醛（AuNPs-CysA-GA）的新型夹心型电化学免疫传感器，它成功地设计用于检测人血浆样品中的 CEA 生物标志物。AuNPs-CysA-GA为CEA抗体的有效固定提供了大的表面积，并确定了固定的CEA抗原的生物活性和稳定性。生物素化抗 CEA 抗体 (Ab1) 固定在玻碳电极 (GCE) 修饰的 AuNPs-CysA-GA 表面。还，二抗（HRP-Ab2）被固定以完成免疫传感器的夹心部分。场发射扫描电子显微镜（FE-SEM 和 EDS）用于监测传感器制造过程。该免疫传感器用于使用差分脉冲伏安法 (DPV) 技术检测 CEA。所提出的界面增加了用于固定大量抗 CEA 抗体的可接触表面积，增加了电导率，提高了稳定性和生物相容性。最后，所提出的免疫传感器的定量下限 (LLOQ) 为 7 ng/mL，线性范围为 0.001-5 μg/L。所提出的免疫测定已成功应用于监测未加工人血浆样品中的 CEA。