Guangdong Key Laboratory of Biomedical Measurements and Ultrasound Imaging, Department of Biomedical Engineering, School of Medicine , Shenzhen University , Shenzhen 518060 , China.
State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering , Southeast University , Nanjing 210096 , China.
Anal Chem. 2020 Feb 18;92(4):2891-2895. doi: 10.1021/acs.analchem.9b05213. Epub 2020 Feb 7.
Multiplexed quantification of mycotoxins is of great significance in food safety. Here, novel photonic crystal (PhC) barcodes with G-quadruplex aptamer encapsulated for label-free multiplex mycotoxins quantification are developed. The probes are immobilized on PhC barcodes to form a molecular beacon (MB), which contains the sequences of mycotoxin aptamers and a G-quadruplex. In the presence of the target, the hairpin structure of MB would open and the region of the G-quadruplex is exposed, which subsequently combines with Thioflavin T (ThT) to produce fluorescence. The relative fluorescence intensity increased as the mycotoxins concentration increased in a linear range from 1.0 pg/mL to 100 ng/mL. Moreover, the multiplexed mycotoxins quantification could be achieved by tuning the structural color of the PhC barcodes. We demonstrate that this method with high accuracy and specificity for multiplexed detection of mycotoxins, with the sensitivity of the detection as low as 0.70 pg/mL. Our results show that G-quadruplex-encapsulated PhC barcodes offer a novel simple and label-free pathway toward the multiplex screen assay of mycotoxins for food safety.
多毒素的多重定量分析在食品安全中具有重要意义。本研究开发了一种新型的光子晶体（PhC）条码，其内部包裹有 G-四链体适体，可用于无标记的多重霉菌毒素定量分析。这些探针被固定在 PhC 条码上，形成分子信标（MB），其中包含霉菌毒素适体和 G-四链体的序列。在目标存在的情况下，MB 的发夹结构会打开，暴露 G-四链体区域，随后与硫黄素 T（ThT）结合产生荧光。相对荧光强度随毒素浓度在 1.0 pg/mL 至 100 ng/mL 的线性范围内增加。此外，通过调整 PhC 条码的结构颜色可以实现多重霉菌毒素的定量分析。我们证明了该方法具有高准确性和特异性，可用于多重检测霉菌毒素，检测灵敏度低至 0.70 pg/mL。我们的结果表明，G-四链体包裹的 PhC 条码为食品安全中霉菌毒素的多重筛选分析提供了一种新颖的简单无标记方法。
