Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, 215163, People's Republic of China.
Suzhou Blood Center, Suzhou, 215006, People's Republic of China.
Anal Chim Acta. 2021 Jun 22;1165:338543. doi: 10.1016/j.aca.2021.338543. Epub 2021 Apr 22.
MicroRNAs (miRNAs) play key regulatory roles in a number of biological processes, which act as critical biomarkers for clinical diagnosis. There are urgent needs to develop advanced tools for accurate and convenient analysis of miRNA in biological circumstances. In this study, an ultrasensitive electrochemical biosensor for miRNA assay is fabricated. Tetrahedral DNA modified gold nanoparticles tags are applied with optimized orientation, which are able to recruit a large number of electrochemical species for remarkable signal responses. Benefiting from the excellent amplification efficiency of the association of strand displacement amplification and catalyzed hairpin assembly, the established method shows ultrahigh sensitivity with the limit of detection as low as 10 aM. A wide linear range from 10 to 10 M is achieved. In addition, this method is capable to specifically discriminate interfering miRNAs with slightly different sequences. The successful assessment of miRNA levels in human serum samples also demonstrates good practical utility. Therefore, the proposed method has great potential to the applications of miRNA expression profiling and biological studies.
微 RNA（miRNA）在许多生物过程中发挥着关键的调节作用，它们是临床诊断的重要生物标志物。因此，人们迫切需要开发先进的工具来准确、便捷地分析生物环境中的 miRNA。本研究构建了一种用于 miRNA 分析的超灵敏电化学生物传感器。采用优化的四面体 DNA 修饰金纳米粒子标签，以优化的方向定位，能够招募大量电化学物质，产生显著的信号响应。得益于链置换扩增和催化发夹组装的结合所带来的优异的放大效率，该方法具有超高的灵敏度，检测限低至 10 aM。同时，该方法实现了从 10 到 10 M 的宽线性范围。此外，该方法能够特异性区分具有略微不同序列的干扰 miRNA。在人血清样本中成功评估 miRNA 水平也证明了该方法具有很好的实际应用价值。因此，该方法在 miRNA 表达谱分析和生物学研究方面具有很大的应用潜力。
