Yan Ziyi, Zhu Ping, Zhou Chaoyi, Kong Dezhao, Ye Hua
School of Grain Science and Technology, Jiangsu University of Science and Technology, Zhenjiang 212003, China.
Jiangsu Provincial Engineering Research Center of Grain Bioprocessing, Jiangsu University of Science and Technology, Zhenjiang 212003, China.
Molecules. 2025 Jul 4;30(13):2853. doi: 10.3390/molecules30132853.
T-2 toxin, a type A trichothecene mycotoxin produced by species, is widely present in cereals and their processed products, posing a significant contaminant in food safety. To address the food safety challenges caused by this toxin, we established a dual signal enhancement by magnetic separation and split aptamer for ultrasensitive T-2 toxin detection. In this method, the introduction of magnetic graphene oxide (MGO) enhanced signal and increased sensitivity by reducing background interference. The shortened split aptamer reduces non-specific binding to MGO via decreased steric hindrance, thereby facilitating rapid target-induced dissociation and signal generation. A FAM fluorophore-labeled split aptamer probe FAM-SpA1-1 was quenched by MGO. While the fluorescence intensity remained nearly unchanged when the unlabeled split aptamer probe SpA1-2 was introduced alone, a significant fluorescence recovery was observed upon simultaneous addition of SpA1-2 and T-2 toxin. This recovery resulted from the cooperative binding of SpA1-1 and SpA1-2 to T-2 toxin, which distanced the FAM-SpA1-1 probe from MGO. Therefore, the proposed biosensor demonstrated excellent stability, reproducibility, and specificity, with a linear response range of 10-500 pM and a limit of detection (LOD) of 0.83 pM. Satisfactory recovery rates were achieved in spiked wheat (86.0-114.2%) and beer (112.0-129.6%) samples, highlighting the biosensor's potential for practical applications in real-sample detection. This study establishes the T-2 toxin split aptamer and demonstrates a novel dual-signal enhancement paradigm that pushes the sensitivity frontier of aptamer-based mycotoxin sensors.
T-2毒素是由某些物种产生的一种A型单端孢霉烯族霉菌毒素，广泛存在于谷物及其加工产品中，是食品安全中的一种重要污染物。为应对这种毒素带来的食品安全挑战，我们建立了一种基于磁分离和分裂适体的双信号增强方法，用于超灵敏检测T-2毒素。在该方法中，磁性氧化石墨烯（MGO）的引入通过减少背景干扰增强了信号并提高了灵敏度。缩短的分裂适体通过减少空间位阻降低了与MGO的非特异性结合，从而促进了靶标诱导的快速解离和信号产生。一种FAM荧光团标记的分裂适体探针FAM-SpA1-1被MGO淬灭。当单独引入未标记的分裂适体探针SpA1-2时，荧光强度几乎保持不变，但同时加入SpA1-2和T-2毒素时，观察到显著的荧光恢复。这种恢复是由于SpA1-1和SpA1-2与T-2毒素的协同结合，使FAM-SpA1-1探针与MGO分离。因此，所提出的生物传感器表现出优异的稳定性、重现性和特异性，线性响应范围为10-500 pM，检测限（LOD）为0.83 pM。在加标的小麦（86.0-114.2%）和啤酒（112.0-129.6%）样品中实现了令人满意的回收率，突出了该生物传感器在实际样品检测中的应用潜力。本研究建立了T-2毒素分裂适体，并展示了一种新型的双信号增强模式，推动了基于适体的霉菌毒素传感器的灵敏度前沿。
