Bi Xiaoya, Luo Lijun, Li Libo, Liu Xiaohong, Chen Bainian, You Tianyan
Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, School of Agricultural Equipment Engineering, Institute of Agricultural Engineering, Jiangsu University, Zhenjiang, Jiangsu, 212013, China.
Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, School of Agricultural Equipment Engineering, Institute of Agricultural Engineering, Jiangsu University, Zhenjiang, Jiangsu, 212013, China; Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, 19104, United States.
Talanta. 2020 Oct 1;218:121159. doi: 10.1016/j.talanta.2020.121159. Epub 2020 May 23.
A new fluorescence aptasensor for Ochratoxin A (OTA) analysis in corn and barley flour was developed owing to the favourable quenching function of cobalt oxyhydroxide (CoOOH) nanosheets. The first combination of graphitic carbon nitride quantum dots (g-CNQDs) and CoOOH nanosheets as efficient energy donor-acceptor pair was reported, and the quenching mechanism was proved by investigating the fluorescence lifetime of g-CNQDs. The aptamer-modified g-CNQDs (g-CNQDs-apt) were adsorbed onto CoOOH nanosheets surface by van der Waals force. Consequently, the Förster resonance energy transfer (FRET) from g-CNQDs-apt to CoOOH nanosheets was initiated, leading to quenched fluorescence. With the addition of OTA, the linear aptamer specifically bound with OTA to form G-quadruplex, which had relatively weak interaction with the CoOOH nanosheets and separated from the nanosheets surface. Thus, the FRET process between g-CNQDs-apt and CoOOH nanosheets was hindered, leading to the fluorescence of g-CNQDs-apt recovered clearly. The developed aptasensor exhibited acceptable detection limit with 0.5 nM and desirable linear relationship from 1 nM to 140 nM. Meanwhile, the aptasensor possessed multiple advantages, including easy operation, rapid detection and high selectivity. Moreover, the aptamer sensing platform was favorably applied for OTA determination in cereal (barley and corn flour), in which the recoveries varied from 94.5% to 101% with the relative standard deviation under 2.24%.
由于氢氧化钴（CoOOH）纳米片具有良好的猝灭功能，开发了一种用于玉米和大麦粉中赭曲霉毒素A（OTA）分析的新型荧光适配体传感器。首次报道了将石墨相氮化碳量子点（g-CNQDs）与CoOOH纳米片组合作为高效的能量供体-受体对，并通过研究g-CNQDs的荧光寿命证明了猝灭机制。适配体修饰的g-CNQDs（g-CNQDs-apt）通过范德华力吸附在CoOOH纳米片表面。因此，引发了从g-CNQDs-apt到CoOOH纳米片的荧光共振能量转移（FRET），导致荧光猝灭。加入OTA后，线性适配体与OTA特异性结合形成G-四链体，其与CoOOH纳米片的相互作用相对较弱，并从纳米片表面分离。因此，g-CNQDs-apt与CoOOH纳米片之间的FRET过程受到阻碍，导致g-CNQDs-apt的荧光明显恢复。所开发的适配体传感器具有0.5 nM的可接受检测限和1 nM至140 nM的良好线性关系。同时，该适配体传感器具有多种优点，包括操作简便、检测快速和选择性高。此外，该适配体传感平台成功应用于谷物（大麦和玉米粉）中OTA的测定，回收率在94.5%至101%之间，相对标准偏差低于2.24%。
