An electrochemical DNA biosensor analytic technique for identifying DNA methylation specific sites and quantify DNA methylation level
An electrochemical DNA biosensor analytic technique for identifying DNA methylation specific sites and quantify DNA methylation level
复制标题
电化学 DNA 生物传感器分析技术，用于识别 DNA 甲基化特定位点并量化 DNA 甲基化水平
DOI：
10.1016/j.bios.2018.12.022
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发表时间：
2019-02-15
影响因子：
12.6
通讯作者：
Zheng, Junsong
中科院分区：
文献类型：
--
作者：
Huang, Jian;Zhang, Shu;Zheng, Junsong
We herein developed a novel electrochemical biosensor to detect DNA methylation level, and to quantitatively analyze multiple methylated sites. Graphene oxide was modified with anti-5-methylcytosine antibody to specifically bind CpG methylation sites, and horseradish peroxidase (HRP)-labeled IgG secondary antibody was bound to the former antibody. In buffer containing H2O2 and hydroquinone, HRP-IgG catalyzed the oxidation of hydroquinone into benzoquinone over H2O2, thereby generating electrochemical reduction signals. The number of 5-methylcytosine was directly proportional to current signal, thereby allowing accurate quantification of methylation level. We also analyzed monomethylated target sequences with different sites, After different methylated sites were captured by the probe, the steric hindrance differences between -CH3 hydrophobic sphere and the electrode surface were induced. The peak current decreased with reducing distance from the electrode surface, so DNA methylation sites were identified by measuring corresponding peak current responses. With a low detection limit (1 fM), this DNA biosensor was suitable for ultrasensitive DNA methylation detection. The linear detection range was 10(-15) M to 10(-8) M. Meanwhile, this method had high specificity, stability and repeatability, thus being widely applicable to the clinical detection of DNA methylation.
