基于类金刚石薄膜的纳米孔制造技术研究

Nanopore-based DNA sequencing technology suffers from some issues such as fragility of the membrane and relatively larger nanopore size. This project proposes to fabricate nanopore by a focused helium ion-beam drilling in a membrane material named diamond-like carbon (DLC), then directly constrict the nanopore to a designed size by ion-beam sculpting. Such nanopore can meet the requirements of DNA sequencing (sub 10nm or even smaller). Compared with the traditional material, Diamond-like carbon membrane not only has as high strength as diamond and graphite, but also shows great advantages in resistance of corrosion and friction. Furthermore, a focused helium ion beam does not require a large area exposure, and also it can fabricate nanopore in different thickness of membranes with a high resolution. This new technology has the possibility to prolong the lifetime of the whole nanopore testing system and solve the crucial problem of instability of nanopore diameter. It is considered to be a method for achieving paralled high-throughput DNA sequencing at a relatively low cost.

DNA纳米孔测序技术中面临纳米孔稳定性差、孔径过大等问题。本项目提出以类金刚石薄膜（DLC:Diamond-like Carbon）作为基材，利用聚焦氦离子束制备纳米孔然后直接进行离子束缩孔，可制备符合DNA测序要求的纳米孔（亚10nm甚至更小）。相比传统的纳米孔制备材料，类金刚石薄膜不仅具有金刚石和石墨高硬度的共同特性，而且具有耐腐蚀、抗摩擦的物理特性以及优良的光学特性。而聚焦氦离子束制备纳米孔不需要大面积曝光，并且分辨率高，可在不同厚度的薄膜上精确定点制备纳米孔。该技术可解决前期研究中纳米孔孔径不稳定以及系统寿命短等问题，并且可实现并行高通量测序，提高测序的准确性，有效降低DNA测序成本。

基于纳米孔的测序技术是下一代DNA测序技术的候选者，但是DNA纳米孔测序技术中面临纳米孔孔径稳定性差、孔径大等问题。本课题以类金刚石薄膜作为基材制备DNA固态纳米孔，类金刚石薄膜不仅具有金刚石和石墨的高硬度特性，而且具有耐腐蚀、抗摩擦等物理特性以及优良的化学特性，本项目可成功制备优良的类金刚石薄膜，并成功进行打孔。可解决纳米孔孔径不稳定以及系统寿命短的问题，提高了测序的准确性。另外，针对目前普遍存在的样品制备繁琐、操作复杂、加工设备昂贵等问题，本项目开发了一种高精度、低成本、大众化、高效快捷加工纳米孔（孔径预计2nm）的途径，提出了一种基于电介质击穿的固态纳米孔制备方法。通过在薄膜两端施加适当的电压或者电流脉冲，根据电介质击穿原理，绝缘薄膜在电场的持续作用下被击穿，最终形成纳米孔通道。