AbstractA lateral flow immunoassay (LFIA) was developed for the determination of fumonisin mycotoxins. The fluorescence of CdSe/ZnS quantum dots (QDs), observed at excitation/emission wavelengths of 365/525 nm, is suppressed by the addition of silver nanoparticles (SNPs) or gold nanoparticles (GNPs) because SNPs overlap the excitation bands of the QDs, and GNPs overlap the emission bands. The fluorescence of the QDs is recovered upon addition of fumonisins, allowing for the sensitive detection in “positive mode” of the target mycotoxin by monitoring the changes of the QDs fluorescence intensity. The SNPs are found to be the most effective quenchers, while the use of GNPs allows for an efficient recovery of fluorescence and can be employed in the LFIA. The method was successfully applied to the fluorometric determination of fumonisins in spiked maize flour samples. The visual detection limit is at the ng·mL−1 level. This is four times lower compared to the colorimetric LFIA based on the use of the conventional gold NPs. Graphical abstractSchematic of the fluorescence quenching lateral flow immunoassay that uses fluorescent quantum dots (QD) and metal nanoparticles (NP) as the quencher: the binding of NP-labelled antibody to the antigen (purple triangle) modulates QD luminescence at the Test line, allowing for ‘positive mode’ detection of fumonisins. The NP accumulation at Control line assures validity of the test.

中文翻译：

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基于金和银纳米粒子对 CdSe/ZnS 量子点荧光的猝灭，用于直接测定伏马菌素真菌毒素的横向流动免疫分析

摘要 开发了一种用于测定伏马菌素真菌毒素的侧向流动免疫分析法 (LFIA)。在 365/525 nm 激发/发射波长下观察到的 CdSe/ZnS 量子点 (QD) 的荧光被添加银纳米颗粒 (SNP) 或金纳米颗粒 (GNP) 抑制，因为 SNP 与 QD 的激发带重叠和 GNP 与发射带重叠。添加伏马菌素后，QD 的荧光会恢复，从而通过监测 QD 荧光强度的变化，以“阳性模式”对目标真菌毒素进行灵敏检测。SNP 被发现是最有效的淬灭剂，而 GNP 的使用允许有效恢复荧光，并可用于 LFIA。该方法已成功应用于加标玉米粉样品中伏马菌素的荧光测定。视觉检测限在ng·mL-1水平。与基于使用传统金 NP 的比色 LFIA 相比，这要低四倍。图解摘要使用荧光量子点 (QD) 和金属纳米粒子 (NP) 作为淬灭剂的荧光猝灭侧流免疫测定的示意图：NP 标记的抗体与抗原（紫色三角形）的结合在测试线调节 QD 发光，允许用于伏马菌素的“阳性模式”检测。控制线上的 NP 积累确保了测试的有效性。图解摘要使用荧光量子点 (QD) 和金属纳米粒子 (NP) 作为淬灭剂的荧光猝灭侧流免疫测定的示意图：NP 标记的抗体与抗原（紫色三角形）的结合在测试线调节 QD 发光，允许用于伏马菌素的“阳性模式”检测。控制线上的 NP 积累确保了测试的有效性。图解摘要使用荧光量子点 (QD) 和金属纳米粒子 (NP) 作为淬灭剂的荧光猝灭侧流免疫测定的示意图：NP 标记的抗体与抗原（紫色三角形）的结合在测试线调节 QD 发光，允许用于伏马菌素的“阳性模式”检测。控制线上的 NP 积累确保了测试的有效性。