Wang Jiayi, Chen Qian, Jin Yongpeng, Zhang Xinpei, He Lidong, Zhang Wanjun, Chen Yiqiang
State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China.
Department of Cancer Genetics and Epigenetics, City of Hope National Medical Center, 1500 East Duarte Road, Duarte, CA, 91010, USA.
Anal Chim Acta. 2020 Sep 1;1128:184-192. doi: 10.1016/j.aca.2020.06.076. Epub 2020 Jul 17.
Aflatoxin M (AFM) is generally used as a biomarker in urine for the assessment of aflatoxin exposure in humans and animals. However, there is no approach for the rapid and on-site monitoring of AFM level in urine. Here, we report a surface enhanced Raman scattering (SERS)-based lateral flow immunosensor built for such a purpose. Raman molecule 5,5-dithiobis-2-nitrobenzoic acid and anti-AFM monoclonal antibody were conjugated with Au (core)@Ag (shell) nanoparticle to serve as SERS nanoprobe. AFM-bovine serum albumin was conjugated with gold nanoparticle and then applied onto nitrocellulose membrane as a visible "GOLD" test line. Quantitation of AFM was performed by the readout of Raman signal from the SERS nanoprobes captured on the test line. After optimizing experimental parameters, the detection limit of this immunosensor can achieve as low as 1.7 pg/mL of AFM in urine, which is far below the recommended tolerable level (30 pg/mL) of AFM in urine. The spiking experiment yielded 93.8%-111.3% recovery with coefficients of variation below 17% demonstrating high assay accuracy and precision. Moreover, this immunosensing assay is fast with an assay time below 20 min. Therefore, the developed immunosensor is a promising tool for the rapid assessment of aflatoxin exposure in the field.
黄曲霉毒素M（AFM）通常用作尿液中的生物标志物，用于评估人类和动物的黄曲霉毒素暴露情况。然而，目前尚无对尿液中AFM水平进行快速现场监测的方法。在此，我们报道了一种基于表面增强拉曼散射（SERS）的侧向流动免疫传感器，其正是为此目的而构建。拉曼分子5,5-二硫代双-2-硝基苯甲酸和抗AFM单克隆抗体与金（核）@银（壳）纳米颗粒偶联，用作SERS纳米探针。AFM-牛血清白蛋白与金纳米颗粒偶联，然后作为可见的“金”检测线应用于硝酸纤维素膜上。通过读取检测线上捕获的SERS纳米探针的拉曼信号对AFM进行定量。优化实验参数后，该免疫传感器对尿液中AFM的检测限可低至1.7 pg/mL，远低于尿液中AFM的推荐耐受水平（30 pg/mL）。加标实验的回收率为93.8%-111.3%，变异系数低于17%，表明检测具有较高的准确性和精密度。此外，这种免疫传感检测速度快，检测时间不到20分钟。因此，所开发的免疫传感器是一种用于现场快速评估黄曲霉毒素暴露情况的有前途的工具。
