Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, Engineering Research Center of Materials-Oriented Chemical Engineering of Xinjiang Production and Construction Corps, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, PR China.
Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, Engineering Research Center of Materials-Oriented Chemical Engineering of Xinjiang Production and Construction Corps, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, PR China.
Bioelectrochemistry. 2021 Dec;142:107931. doi: 10.1016/j.bioelechem.2021.107931. Epub 2021 Aug 16.
Effective signal amplification is a prerequisite for electrochemical immunosensors to achieve ultra-sensitive detection. In this work, we prepared a sandwich-type electrochemical immunosensor for the quantitative detection of carcinoembryonic antigen (CEA). As a base platform, Ag NPs modified aminated two-dimensional nitrogen carbide nanosheets (Ag/g-CN) have good biocompatibility and conductivity. In addition, with the layered structure of Au@SiO/CuO as the signal label, the response current value of HO was monitored by the Amperometric i-t Curve (i-t), so as to realize the accurate measurement of CEA. The presence of SiO nanoframes not only reduces the agglomeration of Au NPs and CuO but also provides good biocompatibility to facilitate the connection of secondary antibodies. Finally, we also verified the signal amplification mechanism of the immunosensor through XPS and other means, and calculated the kinetic parameters of the signal tag, which proved the good peroxidase-like activity of Au@SiO/CuO. Under the best test conditions, the prepared immunosensor has a detection range from 0.01 pg/mL to 80 ng/mL, and the detection limit is as low as 0.0038 pg/mL. The results show that the immunosensor has good analytical performance and it can provide a new method for the clinical diagnosis of CEA.
有效信号放大是电化学免疫传感器实现超灵敏检测的前提。在这项工作中，我们制备了一种用于癌胚抗原（CEA）定量检测的三明治型电化学免疫传感器。作为基底平台，Ag NPs 修饰的氨基二维碳化氮纳米片（Ag/g-CN）具有良好的生物相容性和导电性。此外，以 Au@SiO/CuO 为信号标记的层状结构为基础，通过安培电流曲线（i-t）监测 HO 的响应电流值，从而实现 CEA 的准确测量。SiO 纳米框架的存在不仅减少了 Au NPs 和 CuO 的团聚，还提供了良好的生物相容性，有利于连接二抗。最后，我们还通过 XPS 等手段验证了免疫传感器的信号放大机制，并计算了信号标记的动力学参数，证明了 Au@SiO/CuO 具有良好的过氧化物酶样活性。在最佳测试条件下，制备的免疫传感器的检测范围为 0.01 pg/mL 至 80 ng/mL，检测限低至 0.0038 pg/mL。结果表明，该免疫传感器具有良好的分析性能，可为 CEA 的临床诊断提供新方法。
