Nanochannel-nanopore based DNA sequencing with DNA motion control and reduced entropic noise

项目摘要 为了改进DNA测序和开发实用的RNA测序方法，NHGRI 第一阶段项目的重点是使用固态纳米孔传感器， 通道嵌入氮化硅，电子工作在10 MHz带宽的DNA 测序和直接RNA测序。基本概念涉及使用施加的电压， 驱动单链DNA分子通过一个狭窄的纳米孔， 电解质溶液该电压还驱动电解质离子流过孔，测量 就像电流一样。当分子通过纳米孔时，它们改变了离子的流动， 和结构信息可以通过分析的持续时间和幅度的 导致电流减少。所提出的纳米通道系统解决了与DNA有关的两个问题 用固态纳米孔测序：1）将长链DNA进料至传感元件， 单链构象; 2）通过以下方式减少DNA易位信号中发现的变异性： 减少纳米孔内部DNA的构象变化。具体来说，我们寻求 为了使基于固态离子电流的纳米孔测序成为可能， 重要组件：具有足够紧密尺寸的纳米通道，以允许长链的 DNA以理想构象进入传感纳米孔，超薄纳米孔增加 信噪比和减少孔隙内部的碱基数量，并且最佳地快速 通过低噪声、高带宽的电子设备测量通过这些孔的移位。 我们的方法旨在消除对任何酶的需要，并使DNA分子能够 当它们被引导到纳米孔时受到几何约束和控制。

Project Summary To improve DNA sequencing and to develop practical methods of RNA sequencing, this NHGRI Phase I project focuses on using solid-state nanopore sensors coupled with sub-30nm wide channels embedded into silicon nitride, with electronics operating at 10 MHz bandwidth for DNA sequencing and direct RNA sequencing. The basic concept involves using an applied voltage to drive single-stranded DNA molecules through a narrow nanopore, which separates chambers of electrolyte solution. This voltage also drives a flow of electrolyte ions through the pore, measured as an electric current. When molecules pass through the nanopore they modify the flow of ions, and structural information can be extracted by analysis of the duration and magnitude of the resulting current reductions. The proposed nanochannel system solves two issues relating to DNA sequencing with solid-state nanopores: 1) feeding long strands of DNA to the sensing element in a single-stranded conformation; 2) reducing the variability found in DNA translocation signals by decreasing the conformation variance of DNA within the nanopore interior. Specifically, we seek to make solid-state ionic-current based nanopore sequencing possible by combining three important components: a nanochannel with sufficiently tight dimensions to allow long strands of DNA to enter the sensing nanopore in an ideal conformation, ultra-thin nanopores to increase signal-to-noise and reduce the number of bases within the pore interior, and optimally fast measurement of translocation through these pores with low-noise, high-bandwidth electronics. Our approach aims to eliminate the need for any enzymes and enables DNA molecules to be geometrically constrained and controlled as they are guided to the nanopores.