AbstractThe authors describe an aptamer based assay for the mycotoxin T-2. The method is making use of exponential isothermal amplification reaction (EXPAR) and fluorescent silver nanoclusters (AgNCs). Free T-2 and cDNA (which is a DNA that is partially complementary to the aptamer) compete for binding to aptamer-modified magnetic beads. The cDNA collected by magnetic separation can be used as a primer to trigger EXPAR to obtain ssDNA. The C-base-rich ssDNA binds and reduces Ag(I) ion to form fluorescent AgNCs. Fluorescence is measured at excitation/emission wavelengths of 480/525 nm. T-2 can be detected by fluorometry with a detection limit as low as 30 fg·mL−1. The method was applied to analyse spiked oat and corn, and the average recoveries ranged from 97.3 to 102.3% and from 95.9 to 107.5%, respectively. The results were in good agreement with data of the commercial ELISA kit. The assay is highly sensitive, has a wide analytical range, good specificity and reliable operation. It provides a promising alternative for the standard method for quantitative detection of T-2. Graphical abstractSchematic presentation of fluorometric assay for T-2 based on aptamer-functionalized magnetic beads exponential, isothermal amplification reaction (EXPAR) and fluorescent silver nanoclusters (AgNCs).

中文翻译：

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使用 DNA 修饰的银纳米团簇、适体修饰的磁珠和指数等温扩增对食物毒素 T-2 进行竞争性荧光测定

摘要作者描述了一种基于适体的真菌毒素 T-2 检测。该方法利用指数等温扩增反应（EXPAR）和荧光银纳米团簇（AgNCs）。游离 T-2 和 cDNA（这是一种与适配体部分互补的 DNA）竞争结合适配体修饰的磁珠。磁分离收集的cDNA可作为引物触发EXPAR获得ssDNA。富含 C 碱基的 ssDNA 结合并还原 Ag(I) 离子以形成荧光 AgNCs。在 480/525 nm 的激发/发射波长下测量荧光。T-2 可通过荧光法检测，检测限低至 30 fg·mL-1。该方法用于分析加标燕麦和玉米，平均回收率分别为 97.3% 至 102.3% 和 95.9% 至 107.5%。结果与商业ELISA试剂盒的数据非常一致。该测定法灵敏度高，分析范围广，特异性好，操作可靠。它为定量检测 T-2 的标准方法提供了一种有前景的替代方法。图形摘要基于适体功能化磁珠指数、等温扩增反应 (EXPAR) 和荧光银纳米团簇 (AgNC) 的 T-2 荧光测定的示意图。