A simple and low-cost fluorescence aptasensor was developed for rapid and sensitive signal amplification detection of T-2 mycotoxin (T-2). Dual-terminal-fluorescein amidite (FAM)–labeled aptamer (D-aptamer) acted as a recognition element and signal indicator. The metal organic frameworks (MOFs) of N, N′-bis(2-hydroxyethyl)dithiooxamidato copper (II) (H₂dtoaCu) were as the quencher. The D-aptamer was initially adsorbed to the surface of H₂dtoaCu, leading to efficient quenching of the aptasensor. Upon addition of T-2, the D-aptamer underwent a conformation change to form the T-2/T-2 aptamer complex, which induced the signaling probe to be released from the H₂dtoaCu surface. Thus, the fluorescence intensity (FL) of the D-aptamer was recovered. Versus the single-terminal-FAM-labeled aptamer (S-aptamer), the D-aptamer showed a lower detection limit of 0.39 ng/mL. The aptasensor was also successfully applied to detect T-2 in corn and wheat samples with good recoveries.

Graphical abstract

中文翻译：

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基于金属有机骨架的可切换和信号放大适体传感器作为淬灭剂，用于开启检测 T-2 霉菌毒素

开发了一种简单且低成本的荧光适体传感器，用于快速灵敏地检测 T-2 霉菌毒素 (T-2)。双末端荧光素酰胺 (FAM) 标记的适体 (D-适体) 作为识别元件和信号指示剂。N , N '-双（2-羟乙基）二硫代草酰氨基铜（II）（H ₂ dtoaCu）的金属有机骨架（MOFs）作为猝灭剂。D-适配体最初被吸附到 H ₂ dtoaCu的表面，导致适配体传感器的有效淬灭。添加 T-2 后，D-适配体发生构象变化，形成 T-2/T-2 适配体复合物，诱导信号探针从 H _{2 中}释放dtoaCu 表面。因此，恢复了 D-适体的荧光强度 (FL)。与单末端 FAM 标记的适体（S-适体）相比，D-适体的检测下限为 0.39 ng/mL。适体传感器还成功应用于检测玉米和小麦样品中的 T-2，回收率良好。

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