An electrochemical biosensor for ultratrace terbium based on Tb3+ promoted conformational change of human telomeric G-quadruplex

作者：Zhang Jing; Chen JingHua; Chen RongChun; Chen GuoNan; Fu FengFu^*

来源：Biosensors and Bioelectronics, 2009, 25(2): 378-382.

DOI：10.1016/j.bios.2009.07.029

• Electrochemical biosensor
• Reversible switch
• Terbium
• G-quadruplex
• Human telomeric

A new electrochemical biosensor for the monitoring of ultratrace terbium based on the conformational change of DNA containing a single guanine (G)-rich stretch was described here. The biosensor was fabricated by immobilizing a thiolated DNA containing a single G-rich stretch on the gold surface as probe surface. The G-rich DNA probe was found to be capable of changing its configuration from flexible single-stranded structures to rigid tetramolecular G-quadruplex in the presence of terbium III, which provided a switchable charge transport path for the oxidation of [Fe(CN)(6)](4-). The switchable surface provided a sensing platform for the single-step and reagentless detection of Tb3+. Using this reusable electrochemical sensing platform, a simple, rapid, and selective biosensor for the determination of ultratrace terbium ions with a detection limit of 6.0 x 10(-11) M has been developed. The success in the present biosensor served as a significant step toward the development of monitoring ultratrace Tb3+ in river water or seawater.

• 出版日期2009-10-15
• 单位福州大学; 福建医科大学