Three-Dimensional DNA Nanomachine Combined with Toehold-Mediated Strand Displacement Reaction for Sensitive Electrochemical Detection of MiRNA
Three-Dimensional DNA Nanomachine Combined with Toehold-Mediated Strand Displacement Reaction for Sensitive Electrochemical Detection of MiRNA
复制标题
三维DNA纳米机器结合立足点介导的链置换反应用于灵敏电化学检测miRNA
DOI：
10.1021/acs.langmuir.0c01415
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发表时间：
2020
期刊：
影响因子：
3.9
通讯作者：
Wang Jianxiu
中科院分区：
文献类型：
--
作者：
Lu Hanwen;Tang Hailin;Yi Xinyao;Wang Jianxiu
微小RNA（microRNA，miRNA）是诊断、预后和治疗多种人类癌症的理想生物标志物。在磁珠基体上构建了合理设计的三维DNA纳米机器，磁珠上高密度的金纳米颗粒（AuNPs）和进一步放大的AuNPs导致大量DNA步行者和信号探针锚定在AuNPs上。结合支点介导的链置换反应（SDR），进行miRNA的放大电化学检测。miRNA的存在触发了支点介导的SDR，释放的DNA步行者探针与二茂铁（Fc）标记的信号探针杂交。通过切口核酸内切酶切割双链体使信号探针与磁性纳米复合材料分离。发现Fc部分的氧化电流与miRNA-182在1.0 fM和2 pM之间的浓度成反比。该测定对于区分具有相似序列的miRNA具有高度选择性。该方法可灵敏检测不同时期胶质瘤患者血清中miRNA-182的表达水平。该传感方案对于具有异常miRNA表达的癌症病例的早期诊断和预后具有很大的希望。
MicroRNA (miRNA) serves as an ideal biomarker for diagnosis, prognosis, and therapy of various human cancers. The rationally designed three-dimensional (3D) DNA nanomachine was constructed on the matrixes of magnetic beads, and the high density of gold nanoparticles (AuNPs) on each magnetic bead and further enlargement of the AuNPs lead to the anchoring of numerous DNA walkers and signal probes on the AuNPs. With the combination of toehold-mediated strand displacement reaction (SDR), amplified electrochemical detection of miRNA is performed. The existence of miRNA triggers the toehold-mediated SDR and the released DNA walker probe is hybridized with the ferrocene (Fc)-tagged signal probe. The cleavage of the duplex by the nicking endonuclease detaches the signal probe from the magnetic nanocomposites. The oxidation current of Fc moieties was found to be inversely proportional to the concentrations of miRNA-182 between 1.0 fM and 2 pM. The assay is highly selective for discrimination of miRNAs with similar sequences. The feasibility of the method for sensitive detection of the expression levels of miRNA-182 from serum samples of glioma patients at different stages was demonstrated. The sensing protocol holds great promise for early diagnosis and prognosis of the cancer cases with abnormal miRNA expression.