School of Life Sciences, Central South University, Changsha 410013, Hunan, China.
Toxins (Basel). 2018 May 12;10(5):198. doi: 10.3390/toxins10050198.
Ochratoxin A (OTA) is one of the most common mycotoxins contaminating feed and foodstuffs. Therefore, a great deal of concern is associated with AFB1 toxicity. In this work, a fast and sensitive fluorescence aptamer biosensor has been proposed for the OTA assay. In the absence of OTA, the OTA aptamer can form a G-quadruplex structure with thioflavin T (ThT) dye, which results in increased fluorescence. After joining OTA, OTA aptamer combines with OTA and the G-quadruplex can be formed. Only faint fluorescence was finally observed when ThT weakly reacts with the quadruplex. Through this test method, the entire reaction and analysis process of OTA can be completed in 10 min. Under optimal experimental conditions (600 nM OTA-APT, 7 μM ThT, and 3 min incubation time), this proposed assay has a good limit of detection (LOD) of 0.4 ng/mL and shows a good linear relationship within the range of 1.2⁻200 ng/mL under the best experimental conditions. This method has a high specificity for OTA relative to Ochratoxin B (23%) and Aflatoxin B₁ (13%). In addition, the quantitative determination of this method in real samples has been validated using a sample of red wine supplemented with a range of OTA concentrations (1.2 ng/mL, 12 ng/mL, and 40 ng/mL) with recoveries of 96.5% to 107%.
赭曲霉毒素 A（OTA）是污染饲料和食品的最常见霉菌毒素之一。因此，人们非常关注 AFB1 的毒性。在这项工作中，提出了一种快速灵敏的荧光适体生物传感器用于检测 OTA。在没有 OTA 的情况下，OTA 适体能与硫堇（ThT）染料形成 G-四链体结构，导致荧光增强。加入 OTA 后，OTA 适体与 OTA 结合，形成 G-四链体。当 ThT 与四链体弱反应时，最终只能观察到微弱的荧光。通过这种测试方法，可以在 10 分钟内完成 OTA 的整个反应和分析过程。在最佳实验条件下（600 nM OTA-APT、7 μM ThT 和 3 分钟孵育时间），该方法的检测限（LOD）为 0.4 ng/mL，在最佳实验条件下，在 1.2⁻200 ng/mL 范围内呈现良好的线性关系。与赭曲霉毒素 B（23%）和黄曲霉毒素 B₁（13%）相比，该方法对 OTA 具有较高的特异性。此外，使用添加了一系列 OTA 浓度（1.2 ng/mL、12 ng/mL 和 40 ng/mL）的红葡萄酒样品验证了该方法对实际样品的定量测定，回收率为 96.5%至 107%。
