Faculty of Pharmaceutical Sciences, Centre of Excellence in Mycotoxicology and Public Health, Ghent University, Ottergemsesteenweg 460, Ghent 9000, Belgium.
Physical Chemistry, Technische Universität Dresden, Bergstr. 66b, Dresden 01062, Germany.
ACS Appl Mater Interfaces. 2020 Jun 3;12(22):24575-24584. doi: 10.1021/acsami.0c05099. Epub 2020 May 18.
A critical point for the successful development of a fluorescent quantum dot (QD)-based immunoassay is maintaining the high fluorescence quantum yield of QDs during hydrophilization and bioconjugation. In this paper, we carefully designed CdSe/CdS and CdSe/CdS/ZnS core-shell heterostructures and extended them with silica coating of different surface composition allowing preservation of fluorescence quantum yield as high as 70% in aqueous media. The silanized QDs containing epoxy and carboxy surface groups were bioconjugated with monoclonal antibodies. The synthesized fluorescent conjugates were used in a multicolor lateral flow immunoassay for simultaneous determination of two mycotoxins. Zearalenone and deoxynivalenol were chosen as a proof of concept. Cutoff levels for the zearalenone and deoxynivalenol detection were adjusted to be at 40 and 400 μg kg, respectively, complying with the European Commission regulation. Validation of the developed test was performed by analysis of 34 naturally contaminated maize and wheat samples; as a confirmatory method, LC-MS/MS was used.
成功开发基于荧光量子点（QD）的免疫分析的一个关键点是在亲水化和生物偶联过程中保持 QD 的高荧光量子产率。在本文中，我们精心设计了 CdSe/CdS 和 CdSe/CdS/ZnS 核壳异质结构，并对其进行了不同表面组成的硅烷化涂层扩展，从而在水介质中保持高达 70%的荧光量子产率。含有环氧和羧基表面基团的硅烷化 QD 与单克隆抗体进行了生物偶联。合成的荧光缀合物用于多色侧向流动免疫分析，以同时测定两种霉菌毒素。玉米赤霉烯酮和脱氧雪腐镰刀菌烯醇被选为概念验证。玉米赤霉烯酮和脱氧雪腐镰刀菌烯醇检测的截止值分别调整为 40 和 400 μg kg，符合欧盟委员会的规定。通过对 34 个受自然污染的玉米和小麦样本进行分析，对开发的测试进行了验证；LC-MS/MS 被用作确证方法。
