Highly Sensitive MicroRNA Detection by Coupling Nicking-Enhanced Rolling Circle Amplification with MoS2 Quantum Dots

In this work, a label-free and highly sensitive fluorescence assay was constructed for microRNA detection. Nicking-enhanced rolling circle amplification (RCA) induced by G-quadruplex formation is coupled with inner filter effect (IFE)-based quenching effects of MoS2 quantum dots (MoS2 QDs). The padl...

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Bibliographic Details
Published in:Analytical chemistry (Washington) 2020-10, Vol.92 (19), p.13588-13594
Main Authors: Ge, Jia, Hu, Yun, Deng, Ruijie, Li, Zhaohui, Zhang, Kaixiang, Shi, Muling, Yang, Dan, Cai, Ren, Tan, Weihong
Format: Article
Language:English
Subjects:
Amplification
Analytical chemistry
Chemistry
Fluorescence
Hemin
Hybridization
MicroRNAs
miRNA
Molybdenum disulfide
o-Phenylenediamine
Oxidation
Phenylenediamine
Quantum dots
Quenching
Ribonucleic acid
RNA
Selectivity
Target recognition
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Summary:In this work, a label-free and highly sensitive fluorescence assay was constructed for microRNA detection. Nicking-enhanced rolling circle amplification (RCA) induced by G-quadruplex formation is coupled with inner filter effect (IFE)-based quenching effects of MoS2 quantum dots (MoS2 QDs). The padlock probe contains a recognition sequence to target microRNA and an accessible nicking site. The padlock probe is cyclized upon hybridization with target microRNA. Sequentially, amplification initiates a production of a long-concatenated sequence of circular probes. Abundant G-quadruplex sequences are produced via the nicking process and then used as the trigger to initiate the next RCA. In the presence of hemin, numerous hemin/G-quadruplex DNAzymes are formed, which catalyze the oxidation of o-phenylenediamine (OPD) into the colored product 2,3-diaminophenazine, resulting in quenching of the fluorescence of MoS2 QDs. This sensing strategy enables detection of microRNA let-7a with high selectivity and a detection limit of 4.6 fM. The as-prepared sensor was applied for detecting microRNA let-7a in dilute human serum samples and achieved a satisfactory recovery rate, demonstrating its potential in clinic diagnosis of microRNA-associated disease and biochemical research.
ISSN:0003-2700
1520-6882
DOI:10.1021/acs.analchem.0c03405