Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, college of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou, Fujian 350108, China.
Biosens Bioelectron. 2013 Mar 15;41:397-402. doi: 10.1016/j.bios.2012.08.056. Epub 2012 Sep 5.
A novel three-way junction DNAzyme based probe has been designed for the colorimetric sensing of target DNA. Specifically, a DNAzyme-linked hairpin DNA is used as a signal probe. In the presence of target DNA, the signal probe, assistant probe and target DNA can hybridize with each other, resulting in the formation of a three-way junction DNA. At the same time, the signal probe is opened and the DNAzyme sequence in the signal probe is dehybridized. Subsequently, in the presence of hemin, the DNAzyme sequence forms a G-quadruplex-hemin complex, which catalyzes oxidation of 2, 2'-azinobis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) by H(2)O(2) to the colored ABTS(.-)radical. The significant color changes can be distinguished visually. By the combination of the hairpin probe and the three-way junction DNA probe, the proposed sensor exhibits high recognition property for single-nucleotide polymorphisms (SNPs). This sensor allows the detection of target DNA at a concentration as low as 0.25 nmol L(-1). The proposed sensor is easy to fabricate, which avoids the tedious and expensive labeling procedures, and exhibits high selectivity against single-base mismatched DNA.
一种基于三链杂交 DNA 酶的新型探针已被设计用于目标 DNA 的比色传感。具体来说，使用连接 DNA 酶的发夹 DNA 作为信号探针。在存在目标 DNA 的情况下，信号探针、辅助探针和目标 DNA 可以相互杂交，形成三链杂交 DNA。同时，信号探针被打开，信号探针中的 DNA 酶序列解杂交。随后，在血红素存在下，DNA 酶序列形成 G-四链体-血红素复合物，该复合物通过 H(2)O(2)催化 2,2'-联氮双(3-乙基苯并噻唑啉-6-磺酸)(ABTS)的氧化，生成有色 ABTS(.-)自由基。可以通过肉眼观察到明显的颜色变化。通过发夹探针和三链杂交 DNA 探针的组合，该传感器对单核苷酸多态性(SNPs)具有高识别性能。该传感器可以在低至 0.25 nmol L(-1)的浓度下检测到目标 DNA。该传感器易于制备，避免了繁琐和昂贵的标记程序，并且对单碱基错配 DNA 具有高选择性。
