A novel Tb(3+)-promoted G-quadruplex-hemin DNAzyme for the development of label-free visual biosensors.
A novel Tb(3+)-promoted G-quadruplex-hemin DNAzyme for the development of label-free visual biosensors.
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DOI：
10.1016/j.bios.2011.03.029
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发表时间：
2011-06
影响因子：
12.6
通讯作者：
Jing Zhang;Qin-Jun Gao;Pingping Chen;Jinghua Chen;Guonan Chen;Fengfu Fu
中科院分区：
文献类型：
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作者：
Jing Zhang;Qin-Jun Gao;Pingping Chen;Jinghua Chen;Guonan Chen;Fengfu Fu
本文首次报道了Tb ~（3+）促进的G-四链体氯化血红素DNA酶。我们证明微量Tb ~（3+）能诱导富含鸟嘌呤的DNA（5′-TGGGTAGGGCGGGTTGGGAAA-3′）折叠成紧密的反平行G-四链体结构，从而允许G-四链体-氯化血红素DNA酶的形成。该DNA酶能有效催化H2 O2氧化TMB（3，3 ′，5，5 ′-四甲基联苯胺硫酸盐），使TMB溶液由无色变为蓝色，为Tb 3+的无标记视觉检测提供了一个传感平台。利用该传感平台，建立了一种选择性高、灵敏度高的无标记视觉检测痕量Tb 3+的方法。该方法肉眼观察可检测低至1.13 × 10 - 7 M的Tb 3+，紫外可见分光光度法可检测低至9.0 × 10 - 9 M的Tb 3+，具有较好的稳定性和重现性。与K+促进的G-quadruplex-hemin DNAzyme相比，Tb 3+促进的G-quadruplex-hemin DNAzyme具有更高的过氧化物酶活性和更好的特异性，在光学、电化学和化学发光DNA酶生物传感器的开发中具有很大的潜力。
A Tb3+-promoted G-quadruplex-hemin DNAzyme was first reported in here. We demonstrated that trace Tb3+is able to induce guanine-rich DNA (5′-TGGGTAGGGCGGGTTGGGAAA-3′) folding into a compact antiparallel G-quadruplex structure and thus allows the formation of G-quadruplex-hemin DNAzyme. The proposed DNAzyme can effectively catalyze the H2O2-mediated oxidation of TMB (3,3′,5,5′-tetramethylbenzidine sulfate) and leads to a change from colorless to blue in solution color, which provides a sensing platform for the label-free visual detection of Tb3+. Using above sensing platform, a selective and sensitive label-free visual method for the detection of trace Tb3+was developed. The proposed method can be used to detect as low as 1.13 × 10−7M of Tb3+by the naked eyes observation and 9.0 × 10−9M of Tb3+by UV–vis spectrophotometry with a better stability and reproducibility. Compared with K+-promoted G-quadruplex-hemin DNAzyme reported in previous study, the novel Tb3+-promoted G-quadruplex-hemin DNAzyme has much higher peroxidase activity and better specificity, which lead to a great potential in the development of optical, electrochemical and chemiluminescence DNAzyme-based biosensors.