The sandwich-type electrochemiluminescence immunosensor for α-fetoprotein based on enrichment by Fe3O4-Au magnetic nano probes and signal amplification by CdS-Au composite nanoparticles labeled anti-AFP.
The sandwich-type electrochemiluminescence immunosensor for α-fetoprotein based on enrichment by Fe3O4-Au magnetic nano probes and signal amplification by CdS-Au composite nanoparticles labeled anti-AFP.
复制标题
DOI：
10.1016/j.aca.2012.08.036
复制
发表时间：
2012-10
影响因子：
6.2
通讯作者：
Hankun Zhou;Ning Gan;Tianhua Li;Yuting Cao;Saolin Zeng;Lei Zheng;Zhiyong Guo
中科院分区：
文献类型：
--
作者：
Hankun Zhou;Ning Gan;Tianhua Li;Yuting Cao;Saolin Zeng;Lei Zheng;Zhiyong Guo
以磁性捕获探针和Au壳量子点（CdS-Au）为信号标记物，采用夹心免疫反应策略，在玻碳电极上制备了一种新型、灵敏的超痕量甲胎蛋白（AFP）电化学发光（ECL）免疫传感器。将甲胎蛋白（AFP）一抗（Ab 1）固定在核/壳型Fe 3 O 4-Au纳米粒子上，制备了捕获探针，并将其用于捕获血清中的AFP抗原，孵育后形成Fe 3 O 4-Au/Ab 1/AFP复合物。产物可通过磁分离与背景溶液分离。以CdS-Au标记的二抗（Ab 2）为信号标记物（CdS-Au/Ab 2），与Fe_3 O_4-Au/Ab 1/AFP复合物成功偶联，形成了一种新型的免疫复合物（Fe_3 O_4-Au/Ab 1/AFP/Ab 2/CdS-Au）。该信号与用于定量的AFP的一定浓度范围成比例。因此，一个易于使用的免疫传感器与磁性探针和量子点信号标签。该免疫传感器具有高灵敏度和宽浓度范围，AFP在0.0005至5.0ngmL− 1之间，检测限为0.2pgmL−1。将磁探针的使用与血清中痕量水平的肿瘤标志物的预浓缩和分离相结合。由于信号标签的放大，免疫传感器具有高度的灵敏度，这可以为临床应用提供快速，简单，选择性和成本效益的检测有效的生物监测提供了很大的希望。
A novel and sensitive sandwich-type electrochemiluminescence (ECL) immunosensor was fabricated on a glassy carbon electrode (GCE) for ultra trace levels of α-fetoprotein (AFP) based on sandwich immunoreaction strategy by enrichment using magnetic capture probes and quantum dots coated with Au shell (CdS-Au) as the signal tag. The capture probe was prepared by immobilizing the primary antibody of AFP (Ab1) on the core/shell Fe3O4-Au nanoparticles, which was first employed to capture AFP antigens to form Fe3O4-Au/Ab1/AFP complex from the serum after incubation. The product can be separated from the background solution through the magnetic separation. Then the CdS-Au labeled secondary antibody (Ab2) as signal tag (CdS-Au/Ab2) was conjugated successfully with Fe3O4-Au/Ab1/AFP complex to form a sandwich-type immunocomplex (Fe3O4-Au/Ab1/AFP/Ab2/CdS-Au), which can be further separated by an external magnetic field and produce ECL signals at a fixed voltage. The signal was proportional to a certain concentration range of AFP for quantification. Thus, an easy-to-use immunosensor with magnetic probes and a quantum dots signal tag was obtained. The immunosensor performed at a level of high sensitivity and a broad concentration range for AFP between 0.0005 and 5.0ngmL−1with a detection limit of 0.2pgmL−1. The use of magnetic probes was combined with pre-concentration and separation for trace levels of tumor markers in the serum. Due to the amplification of the signal tag, the immunosensor is highly sensitive, which can offer great promise for rapid, simple, selective and cost-effective detection of effective biomonitoring for clinical application.