College of Chemistry and Chemical Engineering, Gannan Normal University, Ganzhou 341000, P. R. China.
Analyst. 2019 Aug 16;144(17):5201-5206. doi: 10.1039/c9an01075k.
High sequence homology among miRNA members challenges miRNA analysis. In this paper, we developed a simple and highly selective method based on a novel G-triplex molecular beacon (MBG3) and duplex-specific nuclease signal amplification (DSNSA) for miRNA detection. Herein, this MBG3 is a label-free molecular beacon with a special G-triplex probe. The excellent controllablity of the G-triplex probe allowed our MBG3 to have a short stem, which protected it from DSN digestion. Therefore, DSN cleavage induced false positive signals in most DSN signal amplification strategies have been minimised efficiently without special modifications. Importantly, the improved recognition ability of MBG3, together with the sensitive substrate selectivity of DSN, makes our novel method suitable for miRNA detection with high selectivity. The signal response of similar miRNA sequences with one-base difference has been reduced from 37% to 8% compared to the traditional linear ssDNA probe-DSN-based method.
miRNA 成员之间的高度序列同源性给 miRNA 分析带来了挑战。在本文中，我们开发了一种基于新型 G-三链体分子信标 (MBG3) 和双链特异性核酸酶信号扩增 (DSNSA) 的简单且高度选择性的 miRNA 检测方法。在此，这种 MBG3 是一种无标记的分子信标，具有特殊的 G-三链体探针。G-三链体探针的出色可控性使我们的 MBG3 具有短茎，从而使其免受 DSN 消化。因此，在大多数 DSN 信号放大策略中，DSN 切割引起的假阳性信号已被有效最小化，而无需特殊修改。重要的是，MBG3 的改进识别能力以及 DSN 的敏感底物选择性使我们的新方法适用于具有高选择性的 miRNA 检测。与传统的线性 ssDNA 探针-DSN 相比，具有一个碱基差异的类似 miRNA 序列的信号响应已从 37%降低到 8%。基于方法。
