氮化硅纳米孔对λ-DNA过孔信号的检测.docVIP

  Detection of λ-DNA through silicon nitride nanopores# SI Wei, SHA Jingjie, LIU Lei, QIU Yinghua, CHEN Yunfei** (Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, 5 10 15 20 25 30 35 40 Southeast University, Nanjing, 210096) Abstract: In this paper, the transport dynamics of λ-DNA through silicon nitride nanopores are studied. By fitting the distributions of current blockage by the Multi peak Gaussian distribution function, there are two obvious Gaussian peaks for both the 20 nm and 35 nm nanopores applied in our experiments. The first and second peak blockade currents are induced by the linear and double folded translocation of λ-DNA, respectively. Interestingly, there is only one gaussian peak found in the distribution of the dwell time fo each nanopore experiment though linear and double folded transport events are observed. It is because the linear transport events are much more than the double folded transport events, the dwell time for the double folded tranlocation events may be covered by that for the linerar transport events. It is also found that the linear transport time of λ-DNA is almost the same as λ-DNA translocates through the 20 nm and 35 nm nanopores. That is because the interaction between the nanopore and DNA becomes weak as the pore diameter is much larger than the diameter of single-stranded DNA. We hope the results reported in this paper can provide some helpful suggestions for the development of nanopore technology in DNA sequencing. Key words: Silicon nitride; DNA; nanopore 0 Introduction Nanopore sensors have been developed for the past decade since Kasianowicz et al. [1-4] first showed that an electric field could drive single-stranded DNA (ssDNA) and RNA molecules through α-hemolysin nanopore in a lipid bilayer membrane[1]. They demonstrate the capability of sensing single biomolecules which has inspired extensive interest in third-generation DNA sequencing technology based on nanopore sensors.