National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.
Toxicon. 2010 Jan;55(1):145-52. doi: 10.1016/j.toxicon.2009.07.015. Epub 2009 Jul 23.
We developed a novel silica coating magnetic nanoparticle-based silver enhancement immunoassay (SEIA) for ricin toxin (RT) rapid electrical detection using interdigitated array microelectrodes (IDAMs) as electrodes. This novel system was developed by taking advantage of the separation and enrichment properties of magnetic nanoparticles (MNPs) and the catalytic properties of gold nanoparticles (GNPs). In this system, MNPs labeled with anti-ricin A chain antibody 6A6 were used to capture ricin and GNPs labeled with anti-ricin B chain antibody 7G7 were used as detectors. To enhance the electrical signal, the catalytic properties of GNPs were used to promote silver reduction. In the presence of ricin, a sandwich structure was formed which could be separated by a magnetic field. The sandwich complex was then transferred to IDAMs. The silver particles bridged the IDAM gaps and gave rise to an enhancing electrical signal that was detected by conductivity measurements. The results showed that the sensitivity of the SEIA for ricin electrical detection was five times greater than that of conventional colorimetric sandwich ELISA. Once the antibody used for detection was coated on the plates or MNPs, our system was three times more rapid than colorimetric sandwich ELISA. This rapid and sensitive detection system provides promising new potential for ricin detection.
我们开发了一种新型的基于二氧化硅涂层磁性纳米颗粒的银增强免疫分析（SEIA），用于使用叉指式微电极（IDAMs）作为电极对蓖麻毒素（RT）进行快速电检测。该新型系统利用磁性纳米颗粒（MNPs）的分离和富集特性以及金纳米颗粒（GNPs）的催化特性来开发。在该系统中，用标记有抗蓖麻毒素 A 链抗体 6A6 的 MNPs 来捕获蓖麻毒素，并用标记有抗蓖麻毒素 B 链抗体 7G7 的 GNPs 作为探测器。为了增强电信号，利用 GNPs 的催化特性促进银的还原。在存在蓖麻毒素的情况下，形成三明治结构，可通过磁场分离。然后将三明治复合物转移到 IDAMs 上。银颗粒桥接 IDAM 间隙，产生增强的电信号，通过电导率测量进行检测。结果表明，SEIA 对蓖麻毒素电检测的灵敏度比传统的比色三明治 ELISA 高五倍。一旦用于检测的抗体被涂覆在平板或 MNPs 上，我们的系统比比色三明治 ELISA 快三倍。这种快速灵敏的检测系统为蓖麻毒素检测提供了有前途的新潜力。
