Abstract The attenuation or prevention of aflatoxins effect on agricultural products is still an unresolved problem due to the various influencing factors. Fluorescence fingerprint technique (such as excitation-emission matrix, EEM) has been developed for rapid detection of aflatoxins in liquid and solid samples. Unfortunately, the accuracy is seriously affected by background fluorescence compounds, such as kojic acid derivative (KAD). Therefore, development of more sensitive detection methods based on the enhancement of fluorescence signal is highly important. In this study, the EEM fluorescence technique was used to study the effects of α-, β-, and γ-cyclodextrins (CDs), and organic solvents on the fluorescence intensity of aflatoxin B1 (AFB1) and KAD, and molecular modeling study was also performed for the deeper understanding of these host-guest interactions. Results demonstrated that CDs and methanol could induce a higher fluorescence intensity of AFB1, while KAD presented a certain inhibitory effect on the enhancement of fluorescence signal of AFB1. Among the tested compounds β-CD formed the most stable conformation with AFB1 (the logarithm of binding constant values are approximately 2.22–2.49) and the clathrate compounds caused the highest fluorescence enhancement of AFB1 as well (the ratio of fluorescence intensity values (I/I0) for the presence and absence of CD at 430 nm are about 3.76–7.96). However, no obvious elevation for KAD fluorescence intensity caused by various CDs and organic solvents was observed at 493 nm. A significantly increase of fluorescence intensity was observed at the ratio of I430/I493 by CDs. This suggested that CDs could be used to decrease the interference of KAD, and to improve the accuracy and sensitivity for detection of AFB1, especially for the low concentration level.

中文翻译：

---

黄曲霉毒素 B 1 和相关次生代谢物与天然环糊精的相互作用及其潜在利用

摘要 黄曲霉毒素对农产品的影响受多种影响因素的影响，减弱或预防仍是一个悬而未决的问题。荧光指纹技术（如激发-发射矩阵，EEM）已被开发用于快速检测液体和固体样品中的黄曲霉毒素。不幸的是，准确性受到背景荧光化合物的严重影响，例如曲酸衍生物 (KAD)。因此，开发基于荧光信号增强的更灵敏的检测方法非常重要。本研究采用 EEM 荧光技术研究了 α-、β-和 γ-环糊精 (CDs) 以及有机溶剂对黄曲霉毒素 B1 (AFB1) 和 KAD 荧光强度的影响，还进行了分子建模研究，以更深入地了解这些主客交互。结果表明，CDs和甲醇可以诱导AFB1的荧光强度更高，而KAD对AFB1荧光信号的增强有一定的抑制作用。在测试的化合物中，β-CD 与 AFB1 形成最稳定的构象（结合常数值的对数约为 2.22-2.49），包合物也引起 AFB1 的最高荧光增强（荧光强度值的比值（I/ I0) 在 430 nm 处存在和不存在 CD 约为 3.76–7.96)。然而，在 493 nm 处没有观察到由各种 CD 和有机溶剂引起的 KAD 荧光强度的明显升高。在 I430/I493 的比率下，CDs 观察到荧光强度的显着增加。这表明CDs可用于降低KAD的干扰，提高检测AFB1的准确度和灵敏度，尤其是对低浓度水平的检测。