Chem. J. Chinese Universities ›› 2014, Vol. 35 ›› Issue (8): 1646.doi: 10.7503/cjcu20140321

• Analytical Chemistry • Previous Articles     Next Articles

Label-free Fluorescence Signal Amplifying Detection of DNA Based on Hairpin Probe and Exo Ⅲ

GUO Qiuping1,2,4, ZHAO Xiayu1,2,4, XIE Qin1,2,4, WANG Kemin1,2,3,4,*(), WAN Jun1,2,4, YUAN Baoyin2,3,4, TAN Yuyu2,3,4   

  1. 1. College of Biology
    2. State Key Laboratory of Chemo/Biosensing and Chemometrics
    3. College of Chemistry and Chemical Engineering
    4. Key Laboratory for Bio-Nanotechnology and Molecule Engineering of Hunan Province, Hunan University, Changsha 410082, China
  • Received:2014-04-04 Online:2014-08-10 Published:2014-06-23
  • Contact: WANG Kemin E-mail:kmwang@hnu.cn
  • Supported by:
    Supported by the Major Program of the National Natural Science Foundation of China(No.21190044), the National Natural Science Foundation of China(No.21175035), the National Basic Research Program of China(No.2011CB911002), the International Science & Technology Cooperation Program of China(No.2010DFB30300) and Hunan Provincial Science and Technology Project of China(No.2013FJ4042)

Abstract:

A novel label-free fluorescence signal amplifying method for DNA detection was developed with high specificity and sensitivity based on a long arm hairpin nucleic acid probe and exonuclease Ⅲ(Exo Ⅲ). Without the target DNA, the SYBR Green Ⅰ dye could be embedded into the stem of hairpin nucleic acid probe to generate strong fluorescence. While in the presence of target DNA, Exo Ⅲ could catalyze the stepwise removal of mononucleotides from 3'-OH termini of double-stranded DNA with the degradation of the hairpin probe. After that, the target DNA was released, triggering the next cycle of exonuclease digestion reaction. Then the SYBR Green Ⅰ was continuously released, resulting in fluorescence intensity decreased. It rea-lized the label-free signal amplifying detection of DNA. The detection limit of this method was as low as 320 fmol/L. It can be expected to provide a novel, simple, label-free and rapid tool for DNA detection.

Key words: Hairpin probe, Exo Ⅲ, Label-free, Signal amplification, DNA detection

CLC Number: 

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