Sequence-specific detection of nucleic acids utilizing isothermal enrichment of G-quadruplex DNAzymes

详细信息	查看全文 | 推荐本文 |

• 作者：Hao-Jie Xiao^a ; Ho Chol Hak^a ; ^b ; De-Ming Kong^a ; ^{kongdem@nankai.edu.cn} ; Han-Xi Shen^a
• 关键词：Nucleic acid detection ; Isothermal enrichment ; G-quadruplex ; DNAzyme ; Colorimetric
• 刊名：Analytica Chimica Acta
• 出版年：2012
• 期刊代码：2_00032670
• 类别：ch
• 出版时间：4 June, 2012
• 卷：729
• 期：Complete
• 页码：67-72
• 文件大小：562 K

摘要

G-quadruplex DNAzymes are peroxidase-like complexes formed by nucleic acid G-quadruplexes and hemin. Various chemical sensors and biosensors have been developed, based on such DNAzymes. Here we report a novel, specific nucleic acid detection method utilizing the isothermal amplification strategy of G-quadruplex DNAzymes. In this method, an unlabeled oligonucleotide probe was used. The probing sequence of the oligonucleotide was in the form of a stem-loop structure. A G-rich sequence, containing three GGG repeats, was linked to the 5鈥?end of the stem-loop structure. In the presence of target, the probing sequence hybridized to the target, and a G_n (n 鈮?#xA0;2) repeat was extended from its 3鈥?end. This G_n repeat, together with the three GGG repeats at the 5鈥?end, folded into a G-quadruplex, and displayed enhanced peroxidase acitivity upon hemin binding. Utilizing the dynamic binding interaction between the probe and its target, the enrichment of G-quadruplex DNAzymes was achieved. Using this method, simple, rapid and cost-effective nucleic acid detection could be achieved. This method displayed high target-length tolerance and good detection specificity; one-base mismatch could be judged easily, even by visual inspection. This method may be used as an auxiliary tool for amplified detection of specific DNA targets in some situations, in which isothermal detection is desirable.