Jump to main content
Jump to site search

Issue 10, 2019
Previous Article Next Article

Primer remodeling amplification-activated multisite-catalytic hairpin assembly enabling the concurrent formation of Y-shaped DNA nanotorches for the fluorescence assay of ochratoxin A

Author affiliations

Abstract

DNA can be configured into unique high-order structures due to its significantly high programmability, such as a three-way junction-based structure (denoted Y-shaped DNA), for further applications. Herein, we report a label-free fluorescent signal-on biosensor based on the target-driven primer remodeling rolling circle amplification (RCA)-activated multisite-catalytic hairpin assembly (CHA) enabling the concurrent formation of Y-shaped DNA nanotorches (Y-DNTs) for ultrasensitive detection of ochratoxin A (OTA). Two kinds of masterfully-designed probes, termed Complex I and II, were pre-prepared by the combination of a circular template (CT) with an OTA aptamer (S1), a substrate probe (S2) and hairpin probe 1 (HP1), respectively. Target OTA specifically binds to Complex I, resulting in the release of the remnant element in S2 and successive remodeling into a mature primer for RCA by phi29 DNA polymerase, thus a usable primer-CT complex is produced, which actuates primary RCA. Then, numerous Complex II probes can anneal with the first-generation RCA product (RP) with multiple sites to activate the CHA process. With the participation of endonuclease IV (Endo IV) and phi29, HP1 as a pre-primer containing a tetrahydrofuran abasic site mimic (AP site) in Complex II is converted into a mature primer to initiate additional rounds of RCA. So, countless Y-DNTs are formed concurrently containing a G-quadruplex structure that enables the N-methylmesoporphyrin IX (NMM) to be embedded, generating remarkably strong fluorescence signals. The biosensor was demonstrated to enable rapid and accurate highly efficient and selective detection of OTA with an improved detection limit of as low as 0.0002 ng mL−1 and a widened dynamic range of over 4 orders of magnitude. Meanwhile, this method was proven to be capable of being used to analyze actual samples. Therefore, this proposed strategy may be established as a useful and practical platform for the ultrasensitive detection of mycotoxins in food safety testing.

Graphical abstract: Primer remodeling amplification-activated multisite-catalytic hairpin assembly enabling the concurrent formation of Y-shaped DNA nanotorches for the fluorescence assay of ochratoxin A

Back to tab navigation

Supplementary files

Article information


Submitted
16 Feb 2019
Accepted
28 Mar 2019
First published
01 Apr 2019

Analyst, 2019,144, 3389-3397
Article type
Paper

Primer remodeling amplification-activated multisite-catalytic hairpin assembly enabling the concurrent formation of Y-shaped DNA nanotorches for the fluorescence assay of ochratoxin A

J. Wang, Y. Wang, S. Liu, H. Wang, X. Zhang, X. Song, J. Yu and J. Huang, Analyst, 2019, 144, 3389
DOI: 10.1039/C9AN00316A

Social activity

Search articles by author

Spotlight

Advertisements