MicroRNA Detection through DNAzyme-Mediated Disintegration of Magnetic Nanoparticle Assemblies

Bo Tian*, Yuanyuan Han, Erik Wetterskog, Marco Donolato, Mikkel Fougt Hansen, Peter Svedlindh, Mattias Strömberg

*Corresponding author for this work

    Research output: Contribution to journalJournal articleResearchpeer-review

    312 Downloads (Pure)


    DNA-assembled nanoparticle superstructures offer numerous bioresponsive properties that can be utilized for point-of-care diagnostics. Functional DNA sequences such as deoxyribozymes (DNAzymes) provide novel bioresponsive strategies and further extend the application of DNA-assembled nanoparticle superstructures. In this work, we describe a microRNA detection biosensor that combines magnetic nanoparticle (MNP) assemblies with DNAzyme-assisted target recycling. The DNA scaffolds of the MNP assemblies contain substrate sequences for DNAzyme and can form cleavage catalytic structures in the presence of target DNA or RNA sequences, leading to rupture of the scaffolds and disintegration of the MNP assemblies. The target sequences are preserved during the cleavage reaction and release into the suspension to trigger the digestion of multiple DNA scaffolds. The high local concentration of substrate sequences in the MNP assemblies reduces the diffusion time for target recycling. The concentration of released MNPs, which is proportional to the concentration of the target, can be quantified by a 405 nm laser-based optomagnetic sensor. For the detection of let-7b in 10% serum, after 1 h of isothermal reaction at 50 °C, we found a linear detection range between 10 pM and 100 nM with a limit of detection of 6 pM. For the quantification of DNA target in buffer solution, a limit of detection of 1.5 pM was achieved. Compared to protein enzyme-based microRNA detection methods, the proposed DNAzyme-based biosensor has an increased stability, a reduced cost and a possibility to be used in living cells, all of which are valuable features for biosensing applications.
    Original languageEnglish
    JournalACS Sensors
    Issue number9
    Pages (from-to)1884-1891
    Number of pages8
    Publication statusPublished - 2018

    Bibliographical note

    This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes.


    • MicroRNA detection
    • DNAzyme
    • Magnetic nanoparticles
    • DNA-assembled superstructures
    • Optomagnetic bioassay


    Dive into the research topics of 'MicroRNA Detection through DNAzyme-Mediated Disintegration of Magnetic Nanoparticle Assemblies'. Together they form a unique fingerprint.

    Cite this