Impedimetric Immobilized DNA-Based Sensor for Simultaneous Detection of Pb2+, Ag+, and Hg2+
Impedimetric Immobilized DNA-Based Sensor for Simultaneous Detection of Pb2+, Ag+, and Hg2+
复制标题
用于同时检测 Pb2、Ag 和 Hg2 的阻抗固定化 DNA 传感器
DOI：
10.1021/ac2014096
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发表时间：
2011-09-01
影响因子：
7.4
通讯作者：
Kraatz, Heinz-Bernhard
中科院分区：
文献类型：
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作者：
Lin, Zhenzhen;Li, Xiaohong;Kraatz, Heinz-Bernhard
以[Fe(CN)(6)]（4-/3-）为氧化还原探针，采用电化学阻抗谱法（EIS）同时检测Fb（2+）、Ag+和Hg2+，该传感器由三个相互作用部分组成：Pb2+与富g DNA链相互作用形成g -四联体，Ag+与C-C错配相互作用形成C-Ag+- c络合物，Hg2+与T-T错配相互作用形成T-Hg2+- t络合物。圆二色性（CD）和UV-vis Tara表明DNA与Pb2+、Ag+或Hg2+发生了相互作用。DNA分别与Pb2+、Ag+和Hg2+相互作用后，电荷转移电阻（R-CT）降低。利用RcT差值（Delta R-CT）选择性检测Pb2+、Ag+和Hg2+，检测限分别为10 pM、10 nM和0.1 nM。为了同时（或平行）检测样品中共存的三种金属离子，EDTA通过屏蔽Pb2+和Hg2+来检测Ag+；用半胱氨酸掩膜Ag+和Hg2+检测Fb(2+)，用富g和富c DNA链混合掩膜Pb2+和Ag+检测Hg2+。最后，该传感器可成功用于犊牛血清和湖水中Pb2+ Ag+和Hg2+的同时检测。
An unlabeled immobilized DNA-based sensor was reported for simultaneous detection of Fb(2+), Ag+, and Hg2+ by electrochemical impedance spectroscopy (EIS) with [Fe(CN)(6)](4-/3-) as redox probe, which consisted of three interaction sections: Pb2+ interaction with G-rich DNA strands to form G-quadruplex, Ag+ interaction with C-C mismatch to form C-Ag+-C complex, and Hg2+ interaction with T-T mismatch to form T-Hg2+-T complex. Circular dichroism (CD) and UV-vis Tara indicated that the interactions between DNA and Pb2+, Ag+, or Hg2+ occurred. Upon DNA interaction with Pb2+, Ag+, and Hg2+, respectively, a decreased charge transfer resistance (R-CT) was obtained. Taking advantage of the RcT difference (Delta R-CT), Pb2+, Ag+, and Hg2+ were selectively detected with the detection limit of 10 pM, 10 nM, and 0.1 nM, respectively. To simultaneously (or parallel) detect the three metal ions coexisting in a sample, EDTA was applied to mask Pb2+ and Hg2+ for detecting Ag+; cysteine was applied to mask Ag+ and Hg2+ for detecting Fb(2+), and the mixture of G-rich and C-rich DNA strands were applied to mask Pb2+ and Ag+ for detecting Hg2+. Finally, the simple and cost-effective sensor could be successfully applied for simultaneously detecting Pb2+ Ag+, and Hg2+ in calf serum and lake water.