摘要
本文基于G-四链体结构和DNA长距自组装技术,构建一种非标记型电化学交流阻抗方法用于铽离子的痕量检测。首先,根据Tb^(3+)诱导单链DNA折叠成G-四链体的性质,设计一组捕获探针(Cp)和信号探针(Tp)序列,组装到电极表面,当Tb^(3+)存在时,诱导Tp从双链结构中解离并折叠成G-四链体,导致电极表面的Cp裸露,进而与辅助探针Ap1、Ap2进行级联式杂交,在电极表面形成长距"三明治"DNA结构,通过电化学交流阻抗技术检测Tb^(3+)加入前后Ret值的变化,实现对Tb^(3+)的超高灵敏检测。在1.0×10^(-15)M^1.0×10^(-12)M范围内,?Ret与Tb^(3+)浓度的对数呈良好的线性关系,方法检测限为3.4×10^(-16)M。将其应用于实际样品中铽离子的痕量检测,结果令人满意。
In this paper, a label free electrochemical impedance spectroscopy （Ret） method was developed based on G-quadrupole structure and DNA long-distance self-assembly technique for Tb3＋ trace detection. First, a set of capture probes （Cp） and signal probe （Tp） sequences were designed and assembled to the electrode surface. In the presence of Tb3＋, it was folded with Tp to form G-quadruplex, resulting in exposing Cp to the surface of the electrode so to be hybridized with the auxiliary probes Apl and Ap2, which formed a long distance ＂sandwich＂ DNA structure. Using this strategy, the Ret changed linearly along with the concentrations of Tb3＋. The linear range was 1.0× 10-15 to 1.0× 10-12 M with a detection limit of 3.4×10-16 M.
作者
陈强
Chen Qiang(Environmental Monitoring Center of Fujian province, Fuzhou, Fujian 350003, Chin)
出处
《福建分析测试》
CAS
2018年第2期19-24,共6页
Fujian Analysis & Testing
关键词
G-四链体
铽离子
长距自组装
G-quadruplex, terbium ion, long-distance self-assembly
