Division of Chemistry and Ionizing Radiation Measurement Technology, Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, China.
Methods. 2013 Dec 15;64(3):276-82. doi: 10.1016/j.ymeth.2013.07.035. Epub 2013 Aug 2.
MicroRNAs (miRNAs) are key regulators of a wide range of cellular processes, and have been identified as promising cancer biomarkers due to their stable presence in serum. As an surface-based electrochemical biosensors which offer great opportunities for low-cost, point-of-care tests (POCTs) of disease-associated miRNAs. Nevertheless, the sensitivity of miRNA sensors is often limited by mass transport and the surface crowding effect at the water-electrode interface. Here, we present a protocol as well as guidelines for ultrasensitive detection of miRNA with DNA nanostructure-based electrochemical miRNA biosensor. By employing the three-dimensional DNA nanostructure-based interfacial engineering approach, we can directly detect as few as attomolar (<1000 copies) miRNAs with high single-base discrimination ability. Since this ultrasensitive electrochemical miRNA sensor (EMRS) is highly reproducible and essentially free of prior target labeling and PCR amplification, it can conveniently and reliably analyze miRNA expression levels in clinical samples from esophageal squamous cell carcinoma (ESCC) patients.
微 RNA（miRNA）是广泛细胞过程的关键调节剂，由于其在血清中的稳定存在，已被确定为有前途的癌症生物标志物。作为一种基于表面的电化学生物传感器，它为疾病相关 miRNA 的低成本、即时检测（POCT）提供了极好的机会。然而，miRNA 传感器的灵敏度通常受到质量传输和水-电极界面处的表面拥挤效应的限制。在这里，我们提出了一种使用基于 DNA 纳米结构的电化学 miRNA 生物传感器超灵敏检测 miRNA 的方案和指南。通过采用基于三维 DNA 纳米结构的界面工程方法，我们可以直接检测低至飞摩尔级（<1000 拷贝）的 miRNA，具有高单碱基分辨能力。由于这种超灵敏电化学 miRNA 传感器（EMRS）具有高度可重复性，并且基本上不需要事先进行靶标标记和 PCR 扩增，因此可以方便可靠地分析来自食管鳞状细胞癌（ESCC）患者的临床样本中的 miRNA 表达水平。
