Highly effective colorimetric and visual detection of nucleic acids using an asymmetrically split peroxidase DNAzyme
Highly effective colorimetric and visual detection of nucleic acids using an asymmetrically split peroxidase DNAzyme
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DOI：
10.1021/ja803507d
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发表时间：
2008-10-01
影响因子：
15
通讯作者：
Zhou, Xiang
中科院分区：
文献类型：
--
作者：
Deng, Minggang;Zhang, Dan;Zhou, Xiang
g -四重体含过氧化物酶DNAzyme是一种由血红素和富含鸟嘌呤的单链DNA（血红素结合DNA适体）组成的复合物，近年来作为一种有吸引力的生物传感催化标记物被广泛应用。其中，结合血红蛋白的DNA适体包含4个GGG重复序列，并可折叠成g -四重体结构。在本文中，我们开发了一种新的分裂模式，将结合血红蛋白的DNA适体分成两部分：一部分具有3个GGG重复序列，另一部分具有1个GGG重复序列，即3:1分裂模式。g -四重体与血红蛋白结合的组合可以作为一种敏感的探针，通过在室温下发出肉眼可见的颜色信号来鉴定单核苷酸多态性。含有过氧化物酶DNAzyme的g -四重体采用3:1分裂模式，当探针匹配长度足够短时，可直接用于snp的鉴定，检测限在nM范围内。当探针的匹配长度较长时，另一种在探针中加入竞争序列的方法也可以有效地进行SNIPS的识别。结果还表明，当突变样本仅占目标DNA总数的5%时，我们可以通过竞争策略检测到信号。
G-quadruplex containing peroxidase DNAzyme is a complex of hemin and a single-stranded guanine-rich DNA (hemin-binding DNA aptamer), which is used as an attractive catalytic label for biosensing recently. Therein, the hemin-binding DNA aptamer contains four GGG repeats and can fold into a G-quadruplex structure. In this paper, we have developed a new split mode to divide the hemin-binding DNA aptamer into two parts: one possesses three GGG repeats, and another part possesses one GGG repeat, namely, the 3:1 split mode. The combination of G-quadruplex and hemin binding could be used as a sensitive probe for the identification of single nucleotide polymorphisms by giving a color signal, visible to the naked eye at room temperature. The G-quadruplex containing peroxidase DNAzyme utilizes the 3:1 split mode and can be directly used for the identification of SNPs with a detection limit in the nM range when the matching length of the probe is short enough. When the matching length of the probe is relatively long, another method adding competition sequences to the probe could also operate effectively for the identification of SNIPS. The results also suggested that we could detect the signal when the mutation sample was only 5% in the total target DNA with a competition strategy.