The crucial role of miRNA in cell regulation and its connection with diverse human cancers as a tumor suppressor or an oncogenic fragment poses great demand for an accurate and rapid approach for highly efficient miRNA detection and imaging in live cells. However, the ability to selectively detect and image miRNA remains a significant challenge in biomedical fields. Herein, a sealed circular probe (CP) has been prepared with copper free click ligation. The big tension force of the ring structure greatly increases the sequence recognition specificity. Toehold initiated strand displacement of CP further amplify the selectivity for miRNA determination. Impressively, the different site of single base mismatch could even be discriminated. More importantly, CP was successfully applied for imaging endogenous miRNA expression in live cells. We believe that this new probe would find wide application in profiling of endogenous miRNA and be potential candidate method for helping us diagnosing miRNA related diseases.

中文翻译：

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张力促进型圆形探针，用于高度选择性的microRNA检测和成像

miRNA在细胞调节中的关键作用及其与多种人类癌症的关系（作为肿瘤抑制物或致癌片段）提出了对在活细胞中高效，高效地进行miRNA检测和成像的准确，快速方法的巨大需求。然而，在生物医学领域，选择性检测和成像miRNA的能力仍然是一项重大挑战。在此，已经制备了具有无铜点击结扎的密封圆形探针（CP）。环状结构的大拉力大大提高了序列识别的特异性。脚趾头引发的CP链置换进一步扩大了miRNA测定的选择性。令人印象深刻的是，甚至可以分辨出单个碱基错配的不同位点。更重要的是，CP已成功应用于成像活细胞中的内源性miRNA表达。