A new strategy for methylated DNA detection based on photoelectrochemical immunosensor using Bi₂S₃ nanorods, methyl bonding domain protein and anti-his tag antibody

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• 作者：Huanshun Yin ; Bing Sun ; Yunlei Zhou ; Mo Wang ; Zhenning Xu ; Zhengliang Fu ; Shiyun Ai
• 关键词：DNA methylation ; Photoelectrochemical immunosensor ; Bi2S3 nanomaterial ; Methyl bonding domain protein ; Anti-his tag antibody
• 刊名：Biosensors and Bioelectronics
• 出版年：2014
• 出版时间：15 January, 2014
• 年：2014
• 卷：51
• 期：Complete
• 页码：103-108
• 全文大小：1078 K

文摘

In this work, we fabricated a novel photoelectrochemical immunosensor for assay of DNA methylation, where Bi₂S₃ nanorods were used as photoelectric conversion material, MBD1 protein (a kind of methyl bonding domain protein) was used as DNA methylation recognizing unit, anti-his tag antibody was used to further inhibit the photocurrent and increase the detection sensitivity. The results demonstrated that Bi₂S₃ possessed excellent photoelectron property. The detection conditions, such as Bi₂S₃ concentration, MBD1 protein concentration, incubation time of MBD1 protein, antibody concentration and antibody incubation time, were optimized. Under optimal experimental conditions, the photocurrent variation was proportional to the logarithm of methylated target DNA concentration from 10^?9 to 10^-13 M with detection limit of 3.5¡Á10^-14 M (S/N=3). Moreover, the immunosensor presented high detection specificity, even distinguishing single-base mismatched sequence.