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Fluorescent miRNA analysis enhanced by mesopore effects of polydopamine nanoquenchers


The combination of fluorophore-labelled single-strand DNA probes and nanomaterial quenchers has shown great potential in miRNA detection. The development of advanced detection systems by understanding and controlling the fluorescence quenching/recovery via nanoquenchers’ microstructures and local morphologies is an attractive area warranting further investigations. Inspired by nanopore sequencing, we presents a novel miRNA sensing strategy composed of fluorophore-labeled DNA as probes, and a type of large-pore-sized mesoporous polydopamine nanoparticles (MPDA-L, 70 nm in diameter) as fluorescence quenchers. It is revealed that the quenching efficiency of MPDA-L toward the fluorophore labelled on the probe, reached to more than 99% at a relatively low particle concentration. Moreover, the mesopores effectively protect the probe DNA from the cleavage by DNase I which was used for signal amplification. Sensitive detection of miRNA with low detection limit of 32-40 pM, as well as a linear detection range up to 5 nM, was realized by the mesopore effects via greatly improved differential affinity of ssDNA and the probe-miRNA heteroduplex toward nanoquenchers’ surface. Interestingly, enhanced DLVO (Derjaguin-Landau-Verwey-Overbeek) repulsion inside the pore surface generated by the negative surface-curvature effect, correlates with the improved duplex detachment and fluorescence recovery. The developed strategy can be successfully applied to quantify down-regulated let-7a and up-regulated miRNA-21 in different type of cancer cells by using total RNA samples from cell lysate. These findings are expected to inspire strategies and pave a way for utilizing porous nanomaterials for constructing miRNA detection systems.

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Publication details

The article was received on 28 Mar 2017, accepted on 13 Jun 2017 and first published on 13 Jun 2017

Article type: Paper
DOI: 10.1039/C7AN00528H
Citation: Analyst, 2017, Accepted Manuscript
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    Fluorescent miRNA analysis enhanced by mesopore effects of polydopamine nanoquenchers

    Z. Wang, J. Zhang, F. Chen and K. Cai, Analyst, 2017, Accepted Manuscript , DOI: 10.1039/C7AN00528H

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