Interference-Free Detection of Genetic Biomarkers Using Synthetic Dipole-Facilitated Nanopore Dielectrophoresis.
Interference-Free Detection of Genetic Biomarkers Using Synthetic Dipole-Facilitated Nanopore Dielectrophoresis.
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DOI：
10.1021/acsnano.6b07570
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发表时间：
2017-02-28
期刊：
影响因子：
17.1
通讯作者：
Gu LQ
中科院分区：
文献类型：
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作者：
Tian K;Decker K;Aksimentiev A;Gu LQ
可极化粒子在非均匀电场中的运动，介电电泳已广泛用于从癌细胞和病毒到生物分子如DNA和蛋白质的生物颗粒的浓缩、分离、分选和运输。然而，目前的介电电泳操作方法不够灵敏，无法选择性地靶向单个分子种类。在这里，我们描述了介电泳原理的应用，用于使用工程生物纳米孔选择性检测DNA和RNA分子。我们方法的关键要素是合成的聚阳离子纳米载体，其选择性地结合到目标生物分子，显著增加它们对纳米孔产生的电场梯度的介电泳响应。纳米载体-靶复合物的介电泳捕获被检测为纳米孔离子电流的瞬时阻断，而任何非靶核酸通过电泳被从纳米孔排斥，因此不干扰由靶捕获产生的信号。引人注目的是，我们表明，即使是适度带电的纳米载体也可以用于捕获任何长度或二级结构的DNA或RNA分子，并同时检测几个分子靶标。这种选择性的多重分子检测技术对于复杂临床样品的实时分析将是高度期望的。
The motion of polarizable particles in a non-uniform electric field, i.e., dielectrophoresis, has been extensively used for concentration, separation, sorting, and transport of biological particles, from cancer cells and viruses to biomolecules such as DNAs and proteins. However, current approaches to dielectrophoretic manipulation are not sensitive enough to selectively target individual molecular species. Here we describe the application of the dielectrophoretic principle for selective detection of DNA and RNA molecules using an engineered biological nanopore. The key element of our approach is a synthetic polycationic nanocarrier that selectively binds to the target biomolecules, dramatically increasing their dielectrophoretic response to the electric field gradient generated by the nanopore. The dielectrophoretic capture of the nanocarrier-target complexes is detected as a transient blockade of the nanopore ionic current while any non-target nucleic acids are repelled from the nanopore by electrophoresis and thus do not interfere with the signal produced by the target’s capture. Strikingly, we show that even modestly charged nanocarriers can be used to capture DNA or RNA molecules of any length or secondary structure and simultaneously detect several molecular targets. Such selective, multiplex molecular detection technology would be highly desirable for real-time analysis of complex clinical samples.