A novel Tb3+-promoted G-quadruplex-hemin DNAzyme for the development of label-free visual biosensors

作者：Zhang, Jing; Gao, QingLan; Chen, PingPing; Chen, JingHua; Chen, GuoNan; Fu, FengFu^*

来源：Biosensors and Bioelectronics, 2011, 26(10): 4053-4057.

DOI：10.1016/j.bios.2011.03.029

• G-quadruplex
• DNAzyme
• Tb3+
• G-quadruplex-hemin DNAzyme
• Biosensors

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 x 10(-7) M of Tb3+ by the naked eyes observation and 9.0 x 10(-9) M 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.

• 出版日期2011-6-15
• 单位福州大学; 福建医科大学