A label-free genosensor for BRCA1 related sequence based on impedance spectroscopy
A label-free genosensor for BRCA1 related sequence based on impedance spectroscopy
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DOI：
10.1039/c0an00258e
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发表时间：
2010-01-01
期刊：
影响因子：
4.2
通讯作者：
Prakash, Rajiv
中科院分区：
文献类型：
--
作者：
Mohan, Swati;Nigam, Preeti;Prakash, Rajiv
报道了一种基于电化学阻抗谱的乳腺癌DNA杂交传感器的简单方法，将BRCA1相关的19聚寡核苷酸单链DNA序列固定在聚5-羧基吲哚导电聚合物修饰的玻碳电极上。用差示脉冲伏安法、紫外可见光谱、傅里叶变换红外光谱和交流阻抗谱研究了5-羧基吲哚的电聚合、单链DNA的化学固定以及电极表面的杂化事件。在最佳条件下，单链DNA与靶探针杂交前后的阻抗谱发生了显著变化。上述技术被发现足够有效地检测目标DNA序列中的单个碱基不匹配。所有实验均在20 mm Tris-HCl缓冲液(pH 6.5)中进行。在最佳杂交时间内，检测下限为1×10(-17)M，线性范围为1×10(-8)~1×10(-18)。该方法操作简单，不需要任何氧化还原指示剂和标志物，具有较高的灵敏度和选择性。这项技术被成功地用于检测BRCA1相关序列中的单碱基突变。
A simple approach based on electrochemical impedance spectroscopy of a DNA hybridization sensor for breast cancer is reported by immobilizing a BRCA1 related 19 mer oligonucleotides ssDNA sequence on a glassy carbon electrode modified with a poly 5-carboxyindole conducting polymer. Differential pulse voltammetry, UV-vis spectrophotometry, FT-IR and impedance spectroscopy are performed for the study of electropolymerization of 5-carboxyindole, chemical immobilization of ssDNA and the hybridization event at the electrode surface. A significant change is observed in the impedance spectra before and after hybridization of ssDNA with the target probe under optimum conditions. The above described technique is found to be efficient enough to detect a single base mismatch in a target DNA sequence. All the experiments are performed in Tris-HCl buffer 20 mM( pH 6.5). A detection limit of 1 x 10(-17) M with a linear range from 1 x 10(-8) to 1 x 10(-18) is obtained after hybridization for the optimum time period. The proposed method is simple, free from any redox indicator/marker and possesses high sensitivity and selectivity. This technique is successfully demonstrated for detection of a single base mutation in a BRCA1 related sequence.