School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China.
Anal Methods. 2021 Jan 28;13(4):462-468. doi: 10.1039/d0ay02017f. Epub 2021 Jan 13.
Aflatoxin B1 (AFB1) is one of the most carcinogenic chemicals. A novel fluorescence resonance energy transfer (FRET) sensor based on aptamer recognition technology is proposed for the sensitive detection of AFB1 in moldy peanuts using Ag nanocubes as energy acceptors and ZnS quantum dots (QDs) as energy donors. Compared to the traditional FRET system based on an Au quencher, Ag nanocubes can not only quench the fluorescence of aptamer modified ZnS QDs, but are also inexpensive. In addition, compared with heavy metal QDs, ZnS QDs are environmentally friendly, have excellent photochemical properties, and are ideal energy donors. Without Ag nanocubes, the aptamer modified ZnS QDs emits blue fluorescence under an ultraviolet lamp. Because the emission spectrum of ZnS and the absorption spectrum of Ag nanocubes meet the requirements of FRET, the fluorescence quenching of ZnS QDs is realized. Nevertheless, with AFB1, the specific binding of aptamer and complementary chain makes the ZnS QDs break away from the Ag nanocubes, which leads to the fluorescence recovery of the ZnS QDs. Under the optimized detection conditions, the linear range of AFB1 was 5 pg mL to 300 ng mL, and there was no obvious reaction with other similar mycotoxins. According to S/N = 3, the detection limit of AFB1 was 2.67 pg mL. The detection of AFB1 in peanut samples shows that the new FRET system can successfully be applied in the future to agricultural products.
黄曲霉毒素 B1（AFB1）是最具致癌性的化学物质之一。本研究提出了一种基于适配体识别技术的新型荧光共振能量转移（FRET）传感器，用于灵敏检测霉变花生中的 AFB1。该传感器以 Ag 纳米立方体作为能量受体，ZnS 量子点（QDs）作为能量供体。与传统基于 Au 猝灭剂的 FRET 系统相比，Ag 纳米立方体不仅可以猝灭修饰有适配体的 ZnS QDs 的荧光，而且价格低廉。此外，与重金属量子点相比，ZnS QDs 环保、具有优异的光化学性能，是理想的能量供体。没有 Ag 纳米立方体时，修饰有适配体的 ZnS QDs 在紫外灯下会发出蓝色荧光。由于 ZnS 的发射光谱和 Ag 纳米立方体的吸收光谱符合 FRET 的要求，因此实现了 ZnS QDs 的荧光猝灭。然而，当存在 AFB1 时，适配体与互补链的特异性结合使 ZnS QDs 脱离 Ag 纳米立方体，导致 ZnS QDs 的荧光恢复。在优化的检测条件下，AFB1 的线性范围为 5 pg mL 至 300 ng mL，与其他类似真菌毒素无明显反应。根据 S/N = 3，AFB1 的检测限为 2.67 pg mL。在花生样品中的 AFB1 检测表明，新的 FRET 系统未来可成功应用于农产品检测。
