Abstract：
A CHA-based fluorescent DNA tetrahedral probe (FDTp) has been designed to detect the microRNAs miR-21 and miR-155 sensitively and specifically in living cells. The design consisted of functional elements (H1, H2, and Protector) connected to a DNA tetrahedron modified with two pairs of fluorophores and quenching groups. In the presence of miR-21, the chain displacement effect was triggered and Cy3 fluorescence was emitted. In the presence of miR-155, the signal of the catalytic hairpin assembly (CHA) between H1 and H2 on FDTp was amplified, making the fluorescence of FAM sensitive to miR-155. Using this method, the detection limit for miR-155 was 5 pM. The FDTp successfully imaged miR-21 and miR-155 in living cells and distinguished a variety of cell lines based on their expression levels of miR-21 and miR-155. The detection and imaging of dual targets in this design ensured the accuracy of tumor diagnosis and provided a new method for early tumor diagnosis.
摘要：
基于CHA的荧光DNA四面体探针（FDTp）已被设计用于在活细胞中敏感且特异性地检测miR-21和miR-155的微小RNA。该设计由功能元件（H1，H2和Protector）组成，该元件与用两对荧光团和猝灭基团修饰的DNA四面体相连。在miR-21的存在下,链置换效应被触发并发射Cy3荧光。在miR-155的存在下，在FDTp上H1和H2之间的催化发夹组装（CHA）的信号被扩增，使FAM的荧光对miR-155敏感。使用此方法，miR-155的检测限为5pM.FDTp成功成像了活细胞中的miR-21和miR-155，并根据miR-21和miR-155的表达水平区分了多种细胞系。该设计对双目标的检测和成像保证了肿瘤诊断的准确性，为肿瘤的早期诊断提供了一种新的方法。
