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⁻¹ to 300 ng mL⁻¹, 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⁻¹. The detection of AFB1 in peanut samples shows that the new FRET system can successfully be applied in the future to agricultural products.

中文翻译：

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基于ZnS量子点和Ag纳米立方体之间新型的供体-受体对的FRET适体传感器，用于黄曲霉毒素B1的灵敏检测

黄曲霉毒素B1（AFB1）是最致癌的化学物质之一。提出了一种基于适体识别技术的新型荧光共振能量转移（FRET）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，用于灵敏花生中AFB1的灵敏检测。与基于Au猝灭剂的传统FRET系统相比，Ag纳米立方体不仅可以猝灭适体修饰的ZnS QD的荧光，而且价格便宜。此外，与重金属量子点相比，ZnS量子点对环境友好，具有出色的光化学性能，是理想的能量供体。没有Ag纳米立方体，适体修饰的ZnS QD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满足FRET的要求，实现了ZnS量子点的荧光猝灭。然而，利用AFB1，适体和互补链的特异性结合使得ZnS QDs从Ag纳米立方体脱离，这导致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^-1至300 ng mL ^-1，与其他相似的真菌毒素没有明显反应。根据S / N ＝ 3，AFB1的检测极限为2.67pgmL ^-1。对花生样品中AFB1的检测表明，新的FRET系统可以在将来成功应用于农产品。