Enzyme-free signal amplification in the DNAzyme sensor via target-catalyzed hairpin assembly

Abstract

A simple, highly sensitive and enzyme-free DNAzyme sensor based on target-catalyzed hairpin assembly is developed, which permits detection of 0.1 pM target DNA. Furthermore, this DNAzyme sensor is capable of detecting target DNA in real samples because of its high selectivity.

Real-Time Detection of Isothermal Amplification Reactions with Thermostable Catalytic Hairpin Assembly

“…In light of these and others’ results, CHA can now be seen to have a number of advantages as a transducer for amplification reactions, including not only its adaptability to temperature and buffer conditions, but also to different detection modalities 28,30 and the incorporation of programmable molecular logic circuits into analytical readouts. 26,27,29 …”

DNA Nanotechnology: From Biology and Beyond

“…The uncatalyzed background signal of the CHA reaction was almost undetectable (less than 0.5 M À1 s À1 ) within 1 day, and the signal amplification was about 100-fold within a few hours. A CHA circuit has been combined with a G-quadruplex DNAzyme to make a sensor with a detection limit as low as 0.1 pM (Zheng et al 2012). CHA reactions can be easily coupled to different analytical methods, such as fluorescence, electrochemistry, colorimetry, and chemiluminescence, with detection limits ranging from 0.1 pM to 1 nM (Li et al 2011b;Zheng et al 2012).…”

“…A CHA circuit has been combined with a G-quadruplex DNAzyme to make a sensor with a detection limit as low as 0.1 pM (Zheng et al 2012). CHA reactions can be easily coupled to different analytical methods, such as fluorescence, electrochemistry, colorimetry, and chemiluminescence, with detection limits ranging from 0.1 pM to 1 nM (Li et al 2011b;Zheng et al 2012). By combining nonenzymatic transducers such as CHA ) with conventional enzyme amplification methods such as the somewhat noise-prone loop-mediated isothermal amplification (LAMP), a sensitive enzymatic, isothermal amplification method (Notomi et al 2000), it has proven possible to generate paperfluidic diagnostic devices (Allen et al 2012) that may prove both cheap and easy to use in point-of-care settings.…”

Label-free fluorescence dual-amplified detection of adenosine based on exonuclease III-assisted DNA cycling and hybridization chain reaction

“…In past decade, many signal amplification strategies have been developed as effective tools to increase the sensitivity of target analysis (Peng et al, 2014;Liu et al, 2013;Ma et al, 2014;Zheng et al, 2012). Exo III-assisted DNA cycling method is one of the commonly used strategies.…”