Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China.
Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China; Molecular Oncology and Epigenetics Laboratory, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
Anal Chim Acta. 2015 May 18;874:59-65. doi: 10.1016/j.aca.2015.03.021. Epub 2015 Apr 2.
MicroRNAs (miRNAs) play an important regulatory role in cells and dysregulation of miRNA has been associated with a variety of diseases, making them a promising biomarker. In this work, a novel biosensing strategy has been developed for label-free detection of miRNA using surface plasmon resonance (SPR) coupled with DNA super-sandwich assemblies and biotin-strepavidin based amplification. The target miRNA is selectively captured by surface-bound DNA probes. After hybridization, streptavidin is employed for signal amplification via binding with biotin on the long DNA super-sandwich assemblies, resulting in a large increase of the SPR signal. The method shows very high sensitivity, capable of detecting miRNA at the concentration down to 9 pM with a wide dynamic range of 6 orders of magnitude (from 1 × 10(-11) M to 1 × 10(-6) M) in 30 min, and excellent specificity with discriminating a single base mismatched miRNA sequence. This biosensor exhibits good reproducibility and precision, and has been successfully applied to the detection of miRNA in total RNA samples extracted from human breast adenocarcinoma MCF-7 cells. It, therefore, offers a highly effective alternative approach for miRNA detection in biomedical research and clinical diagnosis.
微小 RNA（miRNA）在细胞中发挥着重要的调节作用，miRNA 的失调与多种疾病有关，使其成为有前途的生物标志物。在这项工作中，开发了一种新的生物传感策略，用于使用表面等离子体共振（SPR）结合 DNA 超三明治组装和基于生物素-链霉亲和素的扩增进行无标记 miRNA 的检测。目标 miRNA 被表面结合的 DNA 探针选择性捕获。杂交后，链霉亲和素通过与长 DNA 超三明治组装上的生物素结合进行信号放大，导致 SPR 信号的大幅增加。该方法具有非常高的灵敏度，能够在 30 分钟内检测到低至 9 pM 的 miRNA，动态范围为 6 个数量级（从 1×10^(-11) M 到 1×10^(-6) M），并且具有优异的特异性，能够区分单个碱基错配的 miRNA 序列。该生物传感器具有良好的重现性和精度，并已成功应用于从人乳腺癌 MCF-7 细胞中提取的总 RNA 样本中的 miRNA 检测。因此，它为生物医学研究和临床诊断中的 miRNA 检测提供了一种非常有效的替代方法。
