Let-7a, a type of low-expressed microRNAs in cancer cells,hasbeen investigated as a promising biomarker and therapeutic targetfor tumor suppression. Developing simple and sensitive detection methodsfor let-7a is important for cancer diagnosis and treatment. In thiswork, the hybridization chain reaction (HCR) was initiated by let-7avia two hairpin primers (H1 and H2). After the HCR, the remaininghairpin H1 was further detected by lateral flow assay (LFA) and electrochemicalimpedance spectroscopy. For LFA, biotin-modified H1-(bio-H1) and freeH2 were used for HCR. With the decrease of let-7a concentration, thecolor of T line gradually increased. As for electrochemical methods,the H1 '-AuNP-modified electrode was used for detection of bio-H1based on the difference of impedance (Delta R (ct)) detected without and with different concentrations of let-7aparticipating in the HCR. This method could detect let-7a in the rangeof 10.0 fM and 1.0 nM with detection limits of 4.2 fM.
展开▼
