化学学报 ›› 2014, Vol. 72 ›› Issue (3): 378-381.DOI: 10.6023/A13121208 上一篇    下一篇

所属专题: 石墨烯

研究通讯

石墨烯纳米孔的制备及λ-DNA穿孔初步研究

王跃a, 余旭丰b, 刘芸芸c, 谢骁d, 程秀兰b, 黄少铭c, 王志民a   

  1. a 上海交通大学农业与生物学院 上海 200240;
    b 上海交通大学微电子学院 上海 200240;
    c 温州大学化学与材料工程学院 温州 325027;
    d 东南大学-FEI纳皮米中心 南京 210096
  • 收稿日期:2013-12-03 出版日期:2014-03-14 发布日期:2014-02-11
  • 通讯作者: 王志民,E-mail:zmwang@sjtu.edu.cn E-mail:zmwang@sjtu.edu.cn
  • 基金资助:

    项目受国家“863”计划(No. 2012AA02A104);自然科学基金(No. 51302037);上海交通大学重大项目及创新团队培育基金(No. X198775)和上海市重点学科建设基金(No. B209)资助.

Fabrication of Graphene Nanopores and a Preliminary Study on λ-DNA Translocation

Wang Yuea, Yu Xufengb, Liu Yunyunc, Xie Xiaod, Cheng Xiulanb, Huang Shaomingc, Wang Zhimina   

  1. a School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai 200240;
    b School of Microelectronics, Shanghai Jiaotong University, Shanghai 200240;
    c College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325027;
    d SEU-FEI Nano-Pico Center, Southeast University, Nanjing 210096
  • Received:2013-12-03 Online:2014-03-14 Published:2014-02-11
  • Supported by:

    Project supported by the National High Technology Research and Development Program of China (No. 2012AA02A104), the National Natural Science Foundation of China (No. 51302037), the Innovative Research Team fund of Shanghai Jiaotong University (No. X198775) and the Shanghai Key Discipline fund (No. B209).

纳米孔测序是有可能实现“$1,000 Genome”目标的技术之一. 近年来,研究较多的纳米孔有蛋白质纳米孔和硅基材料的固态纳米孔. 蛋白孔寿命比较短,而基于硅基底的固态纳米孔深度显著超过单链DNA相邻碱基的间距,所以,无法实现DNA的单个碱基的分辨. 作者用聚焦离子束先制造氮化硅基底,并在该基底上铺设石墨烯,再用聚焦电子束刻蚀石墨烯,获得直径10 nm以下的纳米孔,初步分析了DNA穿越纳米孔时产生的电信号及穿孔噪音,向单层石墨烯纳米孔测序DNA迈出了一步.

关键词: 石墨烯, 纳米孔, 测序, 聚焦离子束, 聚焦电子束

Nanopore sequencing is among the most promising technologies to achieve the goals of the "$1,000 Genome". Two major types of nanopores have been extensively investigated, protein and silicon-based solid-state nanopores. However, protein pores are short-lived and the length of solid-state nanopores is much larger than the distance between adjacent bases, resulting in incapability to discriminate individual bases along the single-stranded DNA molecules. In this paper, we report λ-DNA translocations through graphene nanopore. A large nanopore with diameter of about 30 nm on silicon nitride substrates were first fabricated using focused ion beam (FIB) system under the beam current of 2 pA, accelerating voltage of 30 kV and sculpting time of 1 s. Individual graphene membranes were suspended onto the substrates to cover the large pore, and nanopores with a diameter less than 10 nm are sculpted in the graphene sheet by focused electron beam (FEB) from a transmission electron microscope (TEM) under a 400 kx magnification times and 300 kV accelerating voltage at 1×105~5×105 A/m2 current density for 2~3 min. The edges of these graphene nanopores became smoother and sharper when the temperature was increased to about 450 ℃, which might help to lower interactions between graphene nanopores and the analytes. The signals of DNA translocation through graphene nanopores had been recorded using a patch clamp amplifier at 10 kHz sampling frequency filtered at 5 kHz via an integrated four-pole low-pass Bessel filter. Analyses of the DNA translocation current traces indicated that different conformations of DNA molecules may exist during entrance into nanopores. In addition, our overall detection platform had a low noise amplitude of around 10 pA, which allowed more sensitive signal detection. Taken together, our observations demonstrate that graphene nanopores are feasible for DNA sensing, leading a forward step towards single-molecule DNA sequencing using monolayered graphene nanopores.

Key words: graphene, nanopore, sequencing, focused ion beam, focused electron beam