Sensitive and reliable analysis of endometrial cancer related microRNA using ternary hybridization hairpin probe

MicroRNA (miRNA), as a kind of small non-coding ribonucleic acid (RNA) that plays a crucial role in regulating transcriptional activities, is a potential biomarker for EC diagnosis. However, reliable detection of miRNA remains a huge challenge, especially for these methods that require multiple probes for signal amplifications, due to the detective deviation caused by variation of probe concentrations. Herein, we present a novel approach for miRNA-205 identification and quantification by employing simply a ternary hairpin probe (TH probe). The ternary hybridization of three sequences results in the construction of the TH probe, which combines high-efficient signal amplification and specific target recognition. A significant number of G-rich sequences have been produced as a result of the enzymes assisted signal amplification process. The G-rich sequences can fold into G-quadruplexes, which can then be detected in a label-free manner by a common fluorescent dye (thioflavin T). Eventually, the approach exhibits a low limit of detection of 278 aM with a wide detection range of 7 orders of magnitude. In summary, the proposed approach possesses a great potential for both clinical diagnosis of EC and fundamental biomedical researches.