Sensitive and label-free electrochemical lead ion biosensor based on a DNAzyme triggered G-quadruplex/hemin conformation
Sensitive and label-free electrochemical lead ion biosensor based on a DNAzyme triggered G-quadruplex/hemin conformation
复制标题
基于 DNAzyme 触发的 G-四联体/氯化血红素构象的灵敏且无标记的电化学铅离子生物传感器
DOI：
10.1016/j.bios.2018.04.054
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发表时间：
2018
影响因子：
12.6
通讯作者：
Liu G
中科院分区：
文献类型：
--
作者：
Wang LeLe;Wen Yanli;Li Lanying;Yang Xue;Li Wen;Meng Jiaoran;Duan Manlei;Sun Xiaoguang;Liu Gang;Yang Xue;Jia Nengqin;Liu G
铅离子（Pb2+）是一种常见的环境污染物，在人体中具有严重的生物蓄积性和毒性。在这项工作中，我们利用DNA四面体探针上的特异性DNAzyme开发了一种新的Pb2+电化学生物传感器，在Pb2+存在的情况下，底物链被切割成两部分，释放出“富g”寡核苷酸，随后形成g -四plex/hemin复合物，在H2O2的辅助下产生可检测的催化电流信号。三维DNA四面体调节探针的密度和取向，从而提高了DNAzyme反应，促进了复杂DNA在电极表面界面的密闭空间内的构象变化。最后，我们的生物传感器的LOD为0.008 nM (3σ)，比EPA的安全限值（15 μg/L或72 nM）低9000倍，比IARC的安全限值（10 μg/L或48.26 nM）低6000倍。所提出的生物传感器的特异性和可重复性得到了很好的证明。
Lead ion (Pb2+) is a common environmental contaminant, which causes serious bioaccumulation and toxicity in human body. In this work, we developed a novel Pb2+electrochemical biosensor using the specific DNAzyme on a DNA tetrahedron probe, in the presence of Pb2+, the substrate strand was cleaved into two parts and released a “G-rich” oligo which subsequently formed a G-quadruplex/hemin complex, generating a detectable catalysis current signal with the assistant of H2O2. The 3-D DNA tetrahedron regulated the density and orientation of the probe and thus improved the DNAzyme reaction, and facilitated the complex DNA conformational change in the confined space of the interface on the electrode surface, Finally, the LOD of our biosensor was proved to be 0.008 nM (3σ), which is 9000 times lower than the safety limit of EPA (15 μg/L or 72 nM), and 6000 times lower than IARC (10 μg/L or 48.26 nM), and more importantly, the specificity and reproducibility of the proposed biosensor was well demonstrated.