G-quadruplex DNA biosensor for sensitive visible detection of genetically modified food

Talanta. 2014 Oct:128:445-9. doi: 10.1016/j.talanta.2014.05.002. Epub 2014 May 13.

Abstract

In this paper, a novel label-free G-quadruplex DNAzyme sensor has been proposed for colorimetric identification of GMO using CaMV 35S promoter sequence as the target. The binary probes can fold into G-quadruplex structure in the presence of DNA-T (Target DNA) and then combine with hemin to form a DNAzyme resembling horseradish peroxidase. The detection system consists of two G-rich probes with 2:2 split mode by using the absorbance and color of ABTS(2-) as signal reporter. Upon the addition of a target sequence, two probes both hybridize with target and then their G-rich sequences combine to form a G-quadruplex DNAzyme, and the DNAzyme can catalyze the reaction of ABTS(2-) with H2O2. Then the linear range is from 0.05 to 0.5 μM while detection limit is 5nM. These results demonstrate that the proposed G-quadruplex DNAzyme method could be used as a simple, sensitive and cost-effective approach for assays of GMO.

Keywords: Colorimetric; G-quadruplex; GMO.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzothiazoles / chemistry
  • Biosensing Techniques / methods*
  • Colorimetry / methods*
  • DNA / chemistry*
  • DNA / genetics
  • DNA, Catalytic / chemistry
  • Food Analysis / methods
  • Food, Genetically Modified*
  • G-Quadruplexes*
  • Glycine max / genetics
  • Guanine / chemistry
  • Hemin / chemistry
  • Reproducibility of Results
  • Sulfonic Acids / chemistry

Substances

  • Benzothiazoles
  • DNA, Catalytic
  • Sulfonic Acids
  • 2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid
  • Guanine
  • Hemin
  • DNA