石墨烯纳米孔的制备及λ-DNA穿孔初步研究  

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

作　　者：王跃[1] 余旭丰 刘芸芸[3] 谢骁[4] 程秀兰[2] 黄少铭[3] 王志民[1] 

机构地区：[1]上海交通大学农业与生物学院,上海200240 [2]上海交通大学微电子学院,上海200240 [3]温州大学化学与材料工程学院,温州325027 [4]东南大学-FEI纳皮米中心,南京210096

出　　处：《化学学报》2014年第3期378-381,共4页Acta Chimica Sinica

基　　金：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);上海市重点学科建设基金(No.B209)资助~~

摘　　要：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.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.

关 键 词：石墨烯 纳米孔 测序 聚焦离子束 聚焦电子束 

分 类 号：TB383.1[一般工业技术—材料科学与工程]