AbstractThe authors describe a fluorometric assay for ochratoxin A (OTA) that is based on the use of graphene oxide and RNase H-aided amplification. On addition of OTA, cAPT is replaced from the APT/cAPT hybridization complex and then hybridizes with RNA labeled with a fluorophore at the 5′-end. Eventually, the fluorophore is released by RNase H cleavage. As the concentration of OTA increases, more cAPTs are displaced, this leading to fluorescence enhancement (best measured at excitation/emission wavelengths of 495/515 nm). This RNase H-assisted cycle response results in strong signal amplification. The limit of detection, calculated on the basis of a signal to noise ratio of 3, is 0.08 ng·mL−1. Response is linear in the 0.08–200 ng·mL−1 OTA concentration range. The method is highly selective for OTA over ochratoxin B and aflatoxin B1. It was applied to the determination of OTA in red wine samples spiked at levels of 1, 7, and 50 ng·mL−1, and the recoveries ranged from 90.9 to 112%. Graphical abstractSchematic of a novel fluorometric aptasensor for ochratoxin A based on the use of graphene oxide and RNase H-aided amplification.

中文翻译：

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基于使用氧化石墨烯和 RNase H 辅助扩增的赭曲霉毒素 A 的荧光适配体测定

摘要作者描述了一种基于使用氧化石墨烯和 RNase H 辅助扩增的赭曲霉毒素 A (OTA) 荧光测定。添加 OTA 后，cAPT 被 APT/cAPT 杂交复合物取代，然后与在 5' 端用荧光团标记的 RNA 杂交。最终，荧光团由 RNase H 裂解释放。随着 OTA 浓度的增加，更多的 cAPT 被置换，这导致荧光增强（最好在 495/515 nm 的激发/发射波长下测量）。这种 RNase H 辅助的循环响应导致强烈的信号放大。在信噪比为 3 的基础上计算的检测限为 0.08 ng·mL-1。响应在 0.08–200 ng·mL-1 OTA 浓度范围内呈线性。该方法对 OTA 的选择性高于赭曲霉毒素 B 和黄曲霉毒素 B1。它用于测定加标浓度为 1、7 和 50 ng·mL−1 的红酒样品中的 OTA，回收率范围为 90.9% 至 112%。基于使用氧化石墨烯和 RNase H 辅助扩增的赭曲霉毒素 A 新型荧光适体传感器示意图。