Zhang Xinlei, Peng Yubo, Yao Li, Shang Huijie, Zheng Zhi, Chen Wei, Xu Jianguo
Engineering Research Center of Bio-Process, Ministry of Education, School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, China.
Key Laboratory for Agricultural Products Processing of Anhui Province, Hefei University of Technology, Hefei 230009, China.
Anal Chem. 2023 Jan 31;95(4):2570-2578. doi: 10.1021/acs.analchem.2c05448. Epub 2023 Jan 18.
Pathogenic bacteria are pathogens widely spread that are capable of causing mild to life-threatening diseases in human beings or other organisms. Rationally organizing the simple helical motif of double-stranded DNA (dsDNA) tiles into designed ensemble structures with architecturally defined collective properties could lead to promising biosensing applications for pathogen detection. In this work, we facilely engineered ultivalent airpin ptamer robe-tethered DNA monolayers (MHAP-DNA monolayers) and applied them to build a fluorescence polarization-responsive ircular isothermal trand isplacement mplification (FP-CSDA) for assay. In this system, the MHAP-DNA monolayers were constructed based on a dsDNA tile-directed self-assembly. A -labeled eporting robe (RP) with an inherent low FP signal serves as the signaling unit. The presence of target leads to the trapping of F RP into the super DNA monolayers via a target-triggered CSDA to peel off the tethered airpin-structured ptamer robes (HAPs) responsible for the binding of RP. As a result, the FP signal of the FAM fluorophore can be remarkably amplified due to the recycling of target and the capacity of structural DNA materials to strongly restrict the free rotation of the FAM fluorophore but without a fluorescence quenching effect. Experimental results demonstrate that the FP assay is able to detect with a low limit of detection (LOD) of 7.2 × 10 CFU/mL and high specificity. As a proof-of-concept study, we envision our study using DNA nanoarchitecture as the foundation to modulate CSDA-based FP assays, promising to open up a new avenue for disease diagnosis, food safety detection, and biochemical studies.
致病细菌是广泛传播的病原体，能够在人类或其他生物体中引起从轻度到危及生命的疾病。将双链DNA（dsDNA）瓦片的简单螺旋基序合理组织成具有明确结构集体性质的设计集合结构，可能会为病原体检测带来有前景的生物传感应用。在这项工作中，我们轻松构建了多价气针适配体袍系链DNA单层（MHAP-DNA单层），并将其应用于构建用于检测的荧光偏振响应环等温链置换扩增（FP-CSDA）。在这个系统中，MHAP-DNA单层是基于dsDNA瓦片定向自组装构建的。一个带有固有低FP信号的荧光素标记报告袍（RP）作为信号单元。靶标的存在会通过靶标触发的CSDA将荧光素标记的RP捕获到超级DNA单层中，从而剥离负责结合RP的系链气针结构适配体袍（HAPs）。结果，由于靶标的循环利用以及结构DNA材料强烈限制荧光素标记物自由旋转的能力，而没有荧光猝灭效应，荧光素标记物的FP信号可以显著放大。实验结果表明，FP检测能够以7.2×10 CFU/mL的低检测限（LOD）和高特异性检测靶标。作为一项概念验证研究，我们设想以DNA纳米结构为基础来调节基于CSDA的FP检测，有望为疾病诊断、食品安全检测和生化研究开辟一条新途径。
