Herein we report a label-free amperometric immunosensor based on reduced graphene oxide-tetraethylene pentamine (rGO-TEPA) hybrid material co-modified by gold and iron-oxide magnetic nanoparticles (Au/MNPs-rGO-TEPA) for detection of carcinoembryonic antigen (CEA). The Au/MNPs-rGO-TEPA nanomaterials were prepared and coated on the working electrode as a sensing platform for antibody (anti-CEA) immobilization and signal amplification. This nanomaterial exhibited some excellent functionalities, such as magnetic and enhanced electrical properties due to its large specific surface area and favorable conductivity. Thionine (Thi) molecule was attached onto rGO-TEPA via π-π stacking and was used as an electrochemically active substance. The immunosensor was developed based on the increase in quantity of CEA captured, proportional to the decrease in peak currents of Thi. Under optimal conditions, the Au/MNPs-rGO-TEPA/Thi-based immunosensor showed impressive linear range from 0.1 pg/mL to 150 ng/mL. In addition, the proposed method had excellent linearity, high sensitivity, and relatively good stability, thereby offering a good platform for early clinical analysis.

A novel label-free binary nanoparticle-decorated reduced graphene oxide-tetraethylene pentamine-based electrochemical immunosensor was developed. Au/MNPs-rGO-TEPA/Thi was used as electrochemical sensitive platform for quantitative detection of CEA.

本文中，我们报告了一种基于金和氧化铁磁性纳米粒子（Au / MNPs-rGO-TEPA）共修饰的还原型氧化石墨烯-四亚乙基五胺（rGO-TEPA）杂化材料的无标记安培免疫传感器，用于检测癌胚抗原（ CEA）。制备了Au / MNPs-rGO-TEPA纳米材料，并将其涂覆在工作电极上，作为固定抗体（抗CEA）和信号放大的传感平台。该纳米材料由于其大的比表面积和有利的导电性而表现出一些优异的功能，例如磁性和增强的电性能。硫氨酸（Thi）分子通过π-π堆积连接到rGO-TEPA上，并用作电化学活性物质。免疫传感器是根据捕获的CEA数量的增加而开发的，与Thi峰值电流的下降成正比。在最佳条件下，基于Au / MNPs-rGO-TEPA / Thi的免疫传感器显示出令人印象深刻的线性范围，从0.1 pg / mL到150 ng / mL。另外，该方法线性度好，灵敏度高，稳定性好，为早期临床分析提供了良好的平台。

开发了一种新型的无标记的二元纳米粒子修饰的还原氧化石墨烯-四亚乙基五胺基电化学免疫传感器。Au / MNPs-rGO-TEPA / Thi被用作电化学检测CEA的定量平台。