A Ratiometric Fluorescent Biosensor Based on Exonuclease ⅢAmplification Strategy for Pathogenic Bacterial Gene Detection
10.11895/j.issn.0253-3820.181091
- VernacularTitle:基于核酸外切酶Ⅲ信号放大的比率型荧光传感器检测致病菌基因
- Author:
Jian-Kang DENG
1
;
Xiao-Juan NIU
;
Ya-Qing LIU
;
Shuo WANG
Author Information
1. 省部共建食品营养与安全国家重点实验室
- Keywords:
Escherichia coli;
Pathogenic bacterial gene;
Fluorescence resonance energy transfer;
Exonuclease Ⅲ;
Ratiometric fluorescence biosensor
- From:
Chinese Journal of Analytical Chemistry
2018;46(5):743-749
- CountryChina
- Language:Chinese
-
Abstract:
Food-borne pathogenic bacteria seriously threaten public health. Based on the mechanism of fluorescence resonance energy transfer (FRET), a ratiometric fluorescence biosensor was constructed by integration of Exo III-based signal amplification strategy. The Cy3 labeled R1-DNA firstly hybridized with Cy5 labeled R2-DNA to form duplex of R1/R2. Cy3 showed a low fluorescence response while Cy5 showed a high fluorescence response. The addition of target pathogenic bacterial gene (Lac Z gene) could de-hybridize the R1/R2,resulting in the fluorescence decreasing of Cy5 and the fluorescence recovering of Cy3. Under the assistance of Exo III, the signal change was further amplified. The detection of limit reached as low as 5.29 pmol/L. The linear detection range was from 10 pmol/L to 2000 pmol/L. The developed ratiomtric detection strategy significantly reduced the possibility of false-positive and false-negative detection results.
