Tang D, Sauceda J C, Lin Z, Ott S, Basova E, Goryacheva I, Biselli S, Lin J, Niessner R, Knopp D
Chair for Analytical Chemistry, Institute of Hydrochemistry, Technische Universität München, Marchioninistrasse 17, D-81377 München, Germany.
Biosens Bioelectron. 2009 Oct 15;25(2):514-8. doi: 10.1016/j.bios.2009.07.030. Epub 2009 Aug 4.
A novel membrane-based lateral-flow immunodipstick assay was developed for the fast screening of aflatoxin B(2) (AFB(2)) as a model compound in food samples. The detector reagent consisted of magnetic nanogold microspheres (MnGMs) with nano-Fe(2)O(3) particles as core and gold nanoparticles as shell, and bio-functionalized with monoclonal anti-AFB(2) antibodies. Manually spotted AFB(2)-bovine serum albumin conjugates (AFB(2)-BSA) and goat anti-mouse IgG on nitrocellulose membrane were used as test and control lines, respectively. As the major advantage, experimental results indicated that the visual detection limit (cutoff value) of the MnGM-based dipstick immunoassay with 0.9 ng/ml AFB(2) was about threefold lower compared to a conventional immunodipstick test using gold nanoparticles as detection reagent. Qualitative results (yes/no) could be obtained within 15 min without expensive equipment. The assay was evaluated with AFB(2) spiked or naturally contaminated samples (n=8), including peanuts, hazelnuts, pistacia and almonds, receiving excellent correspondance with results from high performance liquid chromatography (HPLC). Most importantly, the assay gave no false negative results. By controlling the target antibody this assay can be easily extended for use with other food relevant toxins and thus represents a versatile detection method.
开发了一种基于新型膜的侧向流动免疫试纸条检测方法，用于快速筛查食品样品中的黄曲霉毒素B(2)（AFB(2)）作为模型化合物。检测试剂由以纳米Fe(2)O(3)颗粒为核心、金纳米颗粒为外壳的磁性纳米金微球（MnGMs）组成，并用抗AFB(2)单克隆抗体进行生物功能化。在硝酸纤维素膜上手动点样的AFB(2)-牛血清白蛋白缀合物（AFB(2)-BSA）和山羊抗小鼠IgG分别用作检测线和对照线。作为主要优点，实验结果表明，与使用金纳米颗粒作为检测试剂的传统免疫试纸条检测相比，基于MnGM的试纸条免疫检测对AFB(2)的目视检测限（临界值）约低三倍。无需昂贵设备，15分钟内即可获得定性结果（是/否）。用添加了AFB(2)或天然污染的样品（n = 8）对该检测方法进行评估，这些样品包括花生、榛子、开心果和杏仁，与高效液相色谱（HPLC）结果具有良好的一致性。最重要的是，该检测方法没有假阴性结果。通过控制目标抗体，该检测方法可轻松扩展用于检测其他与食品相关的毒素，因此是一种通用的检测方法。
