School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China.
Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, United Kingdom.
Biosens Bioelectron. 2022 Oct 15;214:114526. doi: 10.1016/j.bios.2022.114526. Epub 2022 Jul 4.
We developed an aptamer recognition-trigged enzyme-free catalyzed hairpin assembly (CHA) assisted signal amplification homogeneous naked-eyes and surface-enhanced Raman scattering (SERS) dual-mode sensor for highly sensitive and portable detection of Aflatoxin B (AFB) in food samples. The recognition of AFB by aptamer induced the generation of HP1-AFB complexes, which hybridized with Ag-labeled hairpin DNA (HP2) and released Ag, subsequently initiating the enzyme-free CHA reaction by a designed helper DNA (HP3) to form double-stranded DNA (HP2-HP3) and accompanied by the release of HP1-AFB complexes. The released HP1-AFB complexes were recognized by HP2 and HP3 again to trigger cascade recycling amplification and resulted in the generation of a larger number of free Ag and dsDNA. Then, methylene blue as Raman tag to intercalate into dsDNA and generating strong SERS signal with the assistance of FeO@Au. Meanwhile, the free Ag induced the AuNPs aggregation and resulted in naked-eye distinguishable color transitions from red to black blue. Benefitting from the efficiently enzyme-free CHA assisted signal amplification and portably dual-mode detection system, this work successfully proposed a novel homogeneous biosensing strategy for highly sensitive and portable detection of AFB. The SERS intensity and visualization signals were linearly correlated with the concentration of AFB ranging from 0.0156 to 31.2 ng mL and 0.61-39 ng mL, and the limit of detections were 1.6 pg mL and 152 pg mL, respectively. This strategy was successfully applied to real samples and provided an alternative approach for the highly sensitive detection of mycotoxins.
我们开发了一种适体识别触发的无酶催化发夹组装（CHA）辅助信号放大均相裸眼和表面增强拉曼散射（SERS）双模传感器，用于食品样品中黄曲霉毒素 B（AFB）的高灵敏和便携式检测。适体与 AFB 的识别诱导 HP1-AFB 复合物的生成，该复合物与 Ag 标记的发夹 DNA（HP2）杂交并释放 Ag，随后通过设计的辅助 DNA（HP3）启动无酶 CHA 反应，形成双链 DNA（HP2-HP3），并伴随着 HP1-AFB 复合物的释放。释放的 HP1-AFB 复合物再次被 HP2 和 HP3 识别，引发级联循环放大，导致更多的游离 Ag 和 dsDNA 的产生。然后，亚甲基蓝作为拉曼标记物插入 dsDNA 中，并在 FeO@Au 的协助下产生强 SERS 信号。同时，游离的 Ag 诱导 AuNPs 聚集，导致裸眼可分辨的颜色从红色到蓝黑色的转变。受益于高效的无酶 CHA 辅助信号放大和便携式双模检测系统，该工作成功提出了一种用于高灵敏和便携式检测 AFB 的新型均相生物传感策略。SERS 强度和可视化信号与 AFB 的浓度呈线性相关，范围从 0.0156 到 31.2 ng mL 和 0.61-39 ng mL，检测限分别为 1.6 pg mL 和 152 pg mL。该策略已成功应用于实际样品，并为真菌毒素的高灵敏检测提供了一种替代方法。
