[e-mail].3 nanoaccordion for electrochemical determination of miRNA-21

• Published in: Mikrochimica acta (1966) 2023-02, Vol.190 (2)
• Main Authors: Ouyang, Ruizhuo, Jiang, Lan, Xie, Xianjin, Yuan, Ping, Zhao, Yuefeng, Li, Yuhao, Tamayo, Abel Ibrahim Balbín
• Format: Article
• Language: English
• Subjects: Detectors; Electric properties; Electron transport; Ethylenediaminetetraacetic acid; MicroRNA
• ISSN: 0026-3672
• DOI: 10.1007/s00604-022-05624-8

Based on a dual signal amplification strategy of novel accordion-like Bi.sub.2O.sub.3-decorated Ti.sub.3C.sub.2 ([e-mail].3) nanocomposites and hybridization chain reaction (HCR), an ultra-sensitive electrochemical biosensor was constructed for miRNA-21 detection. By etching Ti.sub.3AlC.sub.2 with HF, Ti.sub.3C.sub.2 with an accordion-like structure was first obtained and subsequently covered by Bi.sub.2O.sub.3 nanoparticles (NPs), forming [e-mail].3. A layer of Au NPs was electrodeposited on the glassy carbon electrode coated with [e-mail].3, which not only significantly improved the electron transport capacity of the electrode but also greatly increased its surface active area. Upon the immobilization of the thiolated capture probe (SH-CP) on the electrode, the target miRNA-21 specifically hybridized with SH-CP and thus opened its hairpin structure, triggering HCR to form a long double strand with the primers H1 and H2. A large number of the electrochemical indicator molecules were thus embedded inside the long double strands to produce the desirable electrochemical signal at a potential of - 0.19 V (vs. Ag/AgCl). Such dual signal amplification strategy successfully endowed the biosensor with ultra-high sensitivity for miRNA-21 detection in a wide linear range from 1 fM to 100 pM with a detection limit as low as 0.16 fM. The excellent detection of miRNA-21 in human blood plasma displayed a broad prospect in clinical diagnosis. Graphical An ultra-sensitive electrochemical biosensor was successfully constructed for miRNA-21 detection in human blood plasma based on the dual signal amplification strategy of novel accordion-like Bi.sub.2O.sub.3 decorated Ti.sub.3C.sub.2 ([e-mail].3) nanocomposites and hybridization chain reaction.