A switchable and signal-amplified aptasensor based on metal organic frameworks as the quencher for turn-on detection of T-2 mycotoxin

• DOI: 10.1007/s00216-021-03625-9
• Publication Date: 2021-08-24T23:06:36Z
• Authors: Xinliu Tan; Weidao Yu; Yuwen Wang; Ping Song; Qing Xu; Dengming Ming; Yaqiong Yang
• Keywords: Limit of Detection; Biosensing Techniques; Aptamers, Nucleotide; Mycotoxins; Zea mays; 01 natural sciences; Copper; Fluorescence; Metal-Organic Frameworks; Triticum; 0104 chemical sciences

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.