Format

Send to

Choose Destination
See comment in PubMed Commons below
Analyst. 2014 Jun 7;139(11):2884-9. doi: 10.1039/c4an00389f.

A cascade signal amplification strategy for sensitive and label-free DNA detection based on Exo III-catalyzed recycling coupled with rolling circle amplification.

Author information

1
Key Laboratory for Colloid and Interface Chemistry of Education Ministry, Department of Chemistry, Shandong University, Jinan, 250100, P. R. China. wjiang@sdu.edu.cn.

Abstract

A sensitive and label-free fluorescence assay for DNA detection has been developed based on cascade signal amplification combining exonuclease III (Exo III)-catalyzed recycling with rolling circle amplification. In this assay, probe DNA hybridized with template DNA was coupled onto magnetic nanoparticles to prepare a magnetic bead-probe (MNB-probe)-template complex. The complex could hybridize with the target DNA, which transformed the protruding 3' terminus of template DNA into a blunt end. Exo III could then digest template DNA, liberating the MNB-probe and target DNA. The intact target DNA then hybridized with other templates and released more MNB-probes. The liberated MNB-probe captured the primer, circular DNA and then initiated the rolling circle amplification (RCA) reaction, realizing a cascade signal amplification. Using this cascade amplification strategy, a sensitive DNA detection method was developed which was superior to many existing Exo III-based signal amplification methods. Moreover, N-methyl mesoporphyrin IX, which had a pronounced structural selectivity for the G-quadruplex, was used to combine with the G-quadruplex RCA products and generate a fluorescence signal, avoiding the need for any fluorophore-label probes. The spike and recovery experiments in a human serum sample indicated that our assay also had great potential for DNA detection in real biological samples.

PMID:
24752174
DOI:
10.1039/c4an00389f
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Royal Society of Chemistry
    Loading ...
    Support Center