Acta Chimica Sinica ›› 2014, Vol. 72 ›› Issue (3): 378-381.DOI: 10.6023/A13121208 Previous Articles     Next Articles

Special Issue: 石墨烯



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
  • 投稿日期:2013-12-03 发布日期:2014-02-11
  • 通讯作者: 王志民,
  • 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 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).

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