Key Laboratory for Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) , Nanjing University of Posts and Telecommunications , Nanjing 210023 , China.
Division of Physical Biology and Bioimaging Center, Shanghai Synchrotron Radiation Facility, CAS Key Laboratory of Interfacial Physics and Technology , Shanghai Institute of Applied Physics, Chinese Academy of Sciences , Shanghai 201800 , China.
ACS Appl Mater Interfaces. 2019 Mar 27;11(12):11220-11226. doi: 10.1021/acsami.9b01653. Epub 2019 Mar 14.
Sensitive detection of gastric cancer-related biomarkers in human serum provides a promising means for early cancer diagnosis. Herein, we report the design of a nucleic acid circuit for gastric cancer-related microRNA-27a (miRNA-27a) detection based on dual toehold-mediated circular strand displacement amplification (CSDA). In the presence of miRNA-27a, the hybridization between miRNA-27a and probe DNA on magnetic beads through toehold 1 leads to the release of fluorescent DNA and the exposure of a new toehold 2 on linker DNA. After hybridization with catalytic DNA, CSDA is initiated and target miRNA-27a is released to participate in the next cyclic reaction; therefore, a greatly enhanced fluorescence signal is produced. The efficient magnetic separation makes the sensitive detection of miRNA-27a be accomplished within 45 min. With the efficient CSDA, the detection limit of the system (0.8 pM) is ∼100 folds lower than that of the system based on strand displacement without CSDA (79.3 pM). Furthermore, the system also showed good stability and sensitivity to discriminate single-base mismatch, which allows the detection of miRNA-27a in human serum samples. This study provides a novel platform and approach for the rapid quantitative determination of miRNA, which has great potential in clinical diagnosis and disease treatment.
灵敏检测人血清中的胃癌相关生物标志物为早期癌症诊断提供了一种很有前途的方法。在此，我们报告了一种基于双引发子介导的环形链置换扩增（CSDA）的用于检测胃癌相关 microRNA-27a（miRNA-27a）的核酸电路的设计。在存在 miRNA-27a 的情况下，通过引发子 1 使 miRNA-27a 与磁珠上的探针 DNA 杂交，导致荧光 DNA 的释放，并使连接 DNA 上的新引发子 2 暴露。与催化 DNA 杂交后，CSDA 被引发，目标 miRNA-27a 被释放以参与下一个循环反应；因此，产生了大大增强的荧光信号。高效的磁分离使得在 45 分钟内完成了对 miRNA-27a 的灵敏检测。通过高效的 CSDA，该系统的检测限（0.8 pM）比没有 CSDA 的基于链置换的系统（79.3 pM）低约 100 倍。此外，该系统还表现出良好的稳定性和区分单碱基错配的灵敏度，这允许在人血清样本中检测 miRNA-27a。这项研究为 miRNA 的快速定量测定提供了一个新的平台和方法，在临床诊断和疾病治疗方面具有很大的潜力。
