Facile and Label-Free Electrochemical Biosensors for MicroRNA Detection Based on DNA Origami Nanostructures
Facile and Label-Free Electrochemical Biosensors for MicroRNA Detection Based on DNA Origami Nanostructures
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DOI：
10.1021/acsomega.9b01166
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发表时间：
2019-06-01
期刊：
影响因子：
4.1
通讯作者：
Wang, Risheng
中科院分区：
文献类型：
--
作者：
Han, Shuo;Liu, Wenyan;Wang, Risheng
MicroRNAs （miRNAs）已成为早期诊断和增强对癌症和某些疾病的分子发病机制的理解的有前途的分子生物标志物。本文首次利用亚甲基蓝（MB）作为杂交氧化还原指示剂，开发了一种简便、无标记、无扩增的电化学生物传感器，利用DNA折纸纳米结构支撑的DNA探针检测miRNA。具体来说，使用含有多个单链DNA探针的十字形DNA折纸纳米结构可以提高探针的可及性和识别效率（由于合理控制DNA探针的密度）。通过电化学阻抗谱和循环伏安法证实了DNA折纸探针的成功固定及其与靶向miRNA-21分子的杂交。采用差分脉冲伏安法记录靶杂交前后MB的氧化峰电流。该传感器的线性检测范围为0.1 pM ~ 10.0 nM，最低检测限为79.8 fM。通过观察单碱基错配序列的识别能力，研究了miRNA生物传感器的选择性。由于DNA折纸纳米结构具有更大的表面积和前所未有的可定制性，该策略在转化生物医学研究和临床应用中具有灵敏、选择性和无标记的miRNA测定的巨大潜力。
MicroRNAs (miRNAs) have emerged as the promising molecular biomarkers for early diagnosis and enhanced understanding of the molecular pathogenesis of cancers as well as certain diseases. Here, a facile, label-free, and amplification-free electrochemical biosensor was developed to detect miRNA by using DNA origami nanostructure-supported DNA probes, with methylene blue (MB) serving as the hybridization redox indicator, for the first time. Specifically, the use of cross-shaped DNA origami nanostructures containing multiple single-stranded DNA probes at preselected locations on each DNA nanostructure could increase the accessibility and the recognition efficiency of the probes (due to the rational controlled density of DNA probes). The successful immobilization of DNA origami probes and their hybridization with targeted miRNA-21 molecules was confirmed by electrochemical impedance spectroscopy and cyclic voltammetry methods. A differential pulse voltammetry technique was employed to record the oxidation peak current of MB before and after target hybridization. The linear detection range of this biosensor was from 0.1 pM to 10.0 nM, with a lower detection limit of 79.8 fM. The selectivity of the miRNA biosensor was also studied by observing the discrimination ability of single-base mismatched sequences. Because of the larger surface area and unprecedented customizability of DNA origami nanostructures, this strategy demonstrated great potential for sensitive, selective, and label-free determination of miRNA for translational biomedical research and clinical applications.