Research Center for Bioengineering and Sensing Technology, University of Science & Technology Beijing, Beijing 100083, China.
Institute of Biomedical and Health Science, School of Life and Health Science, Anhui Science and Technology University, Fengyang 233100, China.
Molecules. 2019 Jul 30;24(15):2759. doi: 10.3390/molecules24152759.
The authors describe a magnetized carbon nanotube (MCNT) based lateral flow immunoassay (LFI) for visual detection of complement factor B (CFB) in blood. MCNT was prepared by decorating magnetic FeO nanoparticles on multi-walled CNT surface and used as a colored tag for LFI. Monoclonal antibody (mAb, Ab) of CFB was covalently immobilized on the MCNT surface via diimide-activated conjugation between the carboxyl groups on the MCNT surface and amino groups of antibodies. Polyclonal antibody of CFB (Ab) and the secondary antibody were used to prepare the lateral flow test strips. The assay involved: (1) the capture of CFB in blood with the mAb-functionalized MCNT; (2) magnetic separation of the formed CFB-mAb-MCNT and excess of mAb-MCNT from the blood with an external magnet; (3) lateral flow test to capture the CFB-mAb-MCNT complex on the test zone and the excess of mAb-MCNT on the control zone; (4) Recording the intensities of the produced the characteristic brown bands with a portable strip reader and quantitating the concentration of CFB. The proof-of-concept was demonstrated by testing CFB in the buffer, and the detection limit was 5 ng mL under the optimized analytical parameters. CFB in 1 μL of human blood was detected successfully in 30 min with this LFI and the results had a high correlation with commercial ELISA kit. Thence, the MCNT-based LFI offers a rapid and low-cost tool for detecting CFB in human blood directly.
作者描述了一种基于磁性碳纳米管（MCNT）的侧向流动免疫分析（LFI），用于目视检测血液中的补体因子 B（CFB）。MCNT 通过在多壁 CNT 表面上修饰磁性 FeO 纳米颗粒来制备，并用作 LFI 的显色标记。CFB 的单克隆抗体（mAb，Ab）通过 MCNT 表面上的羧基与抗体上的氨基之间的二酰亚胺活化偶联共价固定在 MCNT 表面上。CFB 的多克隆抗体（Ab）和二级抗体用于制备侧向流动测试条。该测定包括：（1）用 mAb 功能化的 MCNT 捕获血液中的 CFB；（2）用外部磁铁从血液中分离形成的 CFB-mAb-MCNT 和过量的 mAb-MCNT；（3）侧向流动测试以捕获测试区上的 CFB-mAb-MCNT 复合物和对照区上的过量 mAb-MCNT；（4）用便携式条带读取器记录产生的特征棕色条带的强度，并定量 CFB 的浓度。通过在缓冲液中测试 CFB 验证了概念验证，在优化的分析参数下，检测限为 5ng/mL。使用这种 LFI，成功地在 30 分钟内检测到 1μL 人血中的 CFB，并且结果与商业 ELISA 试剂盒具有高度相关性。因此，基于 MCNT 的 LFI 提供了一种快速且低成本的工具，可直接用于检测人血中的 CFB。
