Institute of Hydrochemistry, Technische Universität München, Marchioninistrasse 17, D-81377 München, Germany.
Analyst. 2010 Oct;135(10):2661-7. doi: 10.1039/c0an00221f. Epub 2010 Aug 27.
A simple and sensitive fluorescence immunoassay for the detection of aflatoxin B(1) (AFB(1), as a model compound) in food was developed using AFB(1)-bovine serum albumin conjugate (AFB(1)-BSA)-functionalized magnetic beads as immunosensing probes. The recognition elements were prepared by doping of rhodamine B (RB) fluorophore into silica nanoparticles followed by immobilization of monoclonal anti-AFB(1) antibodies on the silica shell. Based on a competitive-type immunoassay format, the assay was performed both in low-binding polypropylene 96-well microtiter plates (MTPs) and in an automated sequential injection (SI) format. Similar detection limit (LOD) of 0.2 ng mL(-1)vs. 0.1 ng mL(-1) but narrower dynamic working linear range of 0.5-7 ng mL(-1)vs. 0.5-30 ng mL(-1) was obtained toward AFB(1) standards with the flow setup compared to the MTP format. Intra-batch assay precision was substantially improved (≤5.3% vs.≤8.7%) by resorting to the SI manifold. The proposed method features unbiased identification of negative (blank) and positive samples. No significant differences at the 95% confidence level were encountered in the analysis of naturally contaminated peanut samples between the proposed immunoassay and liquid chromatography for determination of AFB(1).
建立了一种基于 AFB1-牛血清白蛋白（AFB1-BSA）偶联物功能化的磁性微球作为免疫传感探针，用于检测食品中黄曲霉毒素 B1（AFB1，作为模型化合物）的简单、灵敏的荧光免疫分析方法。识别元件是通过将罗丹明 B（RB）荧光团掺杂到硅纳米粒子中，然后将单克隆抗 AFB1 抗体固定在硅壳上来制备的。基于竞争型免疫分析模式，在低结合性聚丙烯 96 孔微量滴定板（MTP）和自动化顺序注射（SI）格式中进行了检测。与 MTP 格式相比，该流动装置获得了与 AFB1 标准品相似的检测限（LOD）为 0.2 ng mL-1（VS. 0.1 ng mL-1），但动态工作线性范围更窄，为 0.5-7 ng mL-1（VS. 0.5-30 ng mL-1）。通过采用 SI 歧管，批内测定精密度得到了显著提高（≤5.3% VS. ≤8.7%）。该方法具有对阴性（空白）和阳性样品进行无偏识别的特点。在自然污染花生样品的分析中，所提出的免疫测定法与液相色谱法测定 AFB1 之间没有遇到 95%置信水平的显著差异。
