Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China.
Talanta. 2012 May 15;93:433-8. doi: 10.1016/j.talanta.2012.02.047. Epub 2012 Mar 1.
An electrochemical immunosensor for detection of neuron specific enolase (NSE) was designed by immobilizing NSE covalently functionalized single-walled carbon nanotubes (NSE-SWNTs) on a glassy carbon electrode. The NSE-SWNTs not only enhanced electrochemical signal but also presented abundant antigen domains for competitive immunological recognition to anti-NSE primary antibody and then gold nanoprobes labeled with alkaline phosphatase conjugated secondary antibody (AP-anti-IgG/AuNPs). The AP-anti-IgG/AuNPs exhibited highly catalytic activity toward enzyme substrate and significantly amplified the amperometric signal for target molecule detection. Based on the dual signal amplification of SWNTs and gold nanoprobe, the immunosensor could response down to 0.033 ng mL(-1) NSE with a linear range from 0.1 ng mL(-1) to 2 μg mL(-1), and showed acceptable precision and reproducibility. The designed immunosensor was amenable to direct quantification of target protein with a wide range of concentration in complex clinical serum specimens. The assay results were in a good agreement with the reference values. The proposed electrochemical immunosensor provided a pragmatic platform for convenient detection of tumor markers in clinical diagnosis.
一种用于检测神经元特异性烯醇化酶 (NSE) 的电化学免疫传感器是通过将共价功能化的单壁碳纳米管 (NSE-SWNTs) 固定在玻碳电极上来设计的。NSE-SWNTs 不仅增强了电化学信号，还提供了丰富的抗原结构域，用于与抗 NSE 一抗进行竞争性免疫识别，然后与碱性磷酸酶缀合的二抗标记的金纳米探针 (AP-抗-IgG/AuNPs) 进行识别。AP-anti-IgG/AuNPs 对酶底物表现出高度的催化活性，并显著放大了目标分子检测的安培信号。基于 SWNTs 和金纳米探针的双重信号放大，该免疫传感器可以响应低至 0.033ng mL(-1) 的 NSE，线性范围从 0.1ng mL(-1) 到 2μg mL(-1)，具有可接受的精度和重现性。设计的免疫传感器适用于在复杂的临床血清标本中直接定量分析具有广泛浓度范围的目标蛋白。测定结果与参考值吻合良好。该电化学免疫传感器为临床诊断中肿瘤标志物的便捷检测提供了实用的平台。
