Unlabeled hairpin-DNA probe for the detection of single-nucleotide mismatches by electrochemical impedance spectroscopy.
Unlabeled hairpin-DNA probe for the detection of single-nucleotide mismatches by electrochemical impedance spectroscopy.
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DOI：
10.1021/ac7024688
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发表时间：
2008-02
影响因子：
7.4
通讯作者：
Ying Wang;Congjuan Li;Xiaohong Li;Yongfang Li;H. Kraatz
中科院分区：
文献类型：
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作者：
Ying Wang;Congjuan Li;Xiaohong Li;Yongfang Li;H. Kraatz
使用未标记的发夹 DNA 探针通过电化学阻抗谱 (EIS) 检测八个单核苷酸错配。目标链与发夹 DNA 探针杂交后，茎环结构打开并形成双链 DNA。因此，膜厚度增加，这引起杂交前后膜的电性能的差异。采用兰德尔斯等效电路来评估 EIS 结果。发夹DNA（杂交前）和双链体DNA（杂交后）之间电荷转移电阻DeltaR(CT)的差异显示了从发夹到双链体的大结构重排的结果。如果双链体中心存在单核苷酸错配，则在不存在和存在 Zn(2+) 的情况下，B-DNA 之间的电荷转移电阻 DeltaR(CT) 差异可以明确检测所有八个单核苷酸错配。测量了检测限，DeltaR(CT) 可以用低至 10 pM 的目标链浓度来区分单核苷酸错配。
An unlabeled hairpin-DNA probe was used for the detection of eight single-nucleotide mismatches by electrochemical impedance spectroscopy (EIS). Upon hybridization of the target strand with the hairpin DNA probe, the stem-loop structure is opened and forms a duplex DNA. Accordingly, the film thickness is increased, which causes differences in the electrical properties of the film before and after hybridization. Randles equivalent circuits were employed to evaluate the EIS result. The differences in the charge-transfer resistance DeltaR(CT) between hairpin DNA (before hybridization) and duplex DNA (after hybridization) shows the consequence of a large structural rearrangement from hairpin to duplex. If a single-nucleotide mismatch is present in the center of the duplex, the difference in charge-transfer resistance DeltaR(CT) between B-DNA in the absence and presence of Zn(2+) allows the unequivocal detection of all eight single-nucleotide mismatches. The detection limit was measured, and DeltaR(CT) allows the discrimination of a single-nucleotide mismatch with the concentration of the target strand as low as 10 pM.