浓度梯度对生物分子通过纳米孔的影响研究

论文总字数：25272字

摘 要

本实验采用固态纳米孔，首先为确保纳米孔是导通的，先测量没有浓度梯度时的IV曲线。之后改变正极处盐溶液的浓度大小并在负极加入DNA分子，测量过孔信号。当获得同一个纳米孔一系列浓度梯度的过孔信号后，此时可以换一个孔径大小的纳米孔重复上述的实验操作步骤。当获得足够多的过孔信号后就可以使用相应软件进行数据处理，获得DNA过孔信号的散点图和柱状图。之后就可以根据数据图表总结规律得出相应结论。

通常情况下DNA分子产生向下的过孔信号，但是当cis端浓度为0.1mol/L时，过孔信号发生反转现象，会有向上的过孔信号产生。对于同一个纳米孔且cis端为低浓度（lt;1mol/L）的情况下，随着浓度梯度的增加，DNA分子过孔的总滞留时间会增加，脉冲电流的平均阻塞幅值不会改变，并且cis端浓度越大，迁移率越高。而对于不同孔径的纳米孔，在相同浓度梯度的情况下，随着纳米孔孔径的增加，DNA分子过孔的总滞留时间会减少，迁移率变高，也就越容易发生过孔现象。但是对于脉冲电流的平均阻塞幅值，无论孔径大小，都没有明显的变化。

关键词：基因测序；浓度梯度；DNA；固态纳米孔

The influence of concentration gradient on biological molecules through the nanopores

02011123 Li Mengzhi

Supervised by Sha Jingjie

Abstract： Nowdays, the nanopore sequencing technology is the main method among the fourth generation of gene sequencing technologies, which can directly read DNA sequence by physical method. But the technology also exists an obvious obstacle: the speed of DNA through nanopores is so fast, which is beyond the scope of the current testing instrument detection greatly. In order to strengthen the understanding of nanopores, the experiment is in the case of changing concentration gradient of salt solution to study the electrical signal changes. At the same time comparison in the use of different aperture of nanopores, studying the probability of biological molecules (DNA) through the pore and the performance of the electrical characteristics.

This experiment adopts solid-state nanopores. First of all is measuring the I-V curve without concentration gradient to ensure the pore is conductive. Then changing the concentration of salt solution in the positive and put the DNA molecule into the negative to measure signals. When get a series of concentration gradient signal, at this time can change the size of aperture nanopores and repeat the experiment steps. The next is using the corresponding software to process data, get the DNA via signal scatterplot and histogram. Finally, drawing conclusions according to the charts.

Usually the signal of DNA molecules via solid-state nanopores is downward. But when the concentration of cis is 0.1 mol/L, the signal changes and generates upward signal. When the concentration of cis is low(lt; 1 mol/L), with the increase of concentration gradient, the time of DNA molecules via solid-state nanopores increases and the average block pulse current amplitude keeps unchanged. Also the mobility of DNA molecules is faster when the concentration of cis increases. For the different diameter of nanopores, under the condition of the same concentration gradient, with the increase of the pore aperture, DNA molecules via the total residence time decreases and the mobility of DNA molecules increases. But for the average block amplitude of pulse current, regardless of the aperture size, it has no obvious change.

Key words: gene sequencing; concentration gradient; DNA; solid-state nanopores

目 录

1绪论………………………………………………………………………………………………1

1.1 引言……………………………………………………………………………………………1

1.2 研究现状………………………………………………………………………………………1

1.3 研究意义……………………………………………………………………………………3

2 实验原理及方案………………………………………………………………………………4

2.1 DNA通过固态纳米孔的实验原理及方案……………………………………………………4

2.1.1固态纳米孔的电导率…………………………………………………………………4

2.1.2 DNA通过固态纳米孔的易位现象…………………………………………………………4

2.1.3 DNA通过固态纳米孔的方案概述…………………………………………………………5

2.2 浓度梯度实验原理及方案……………………………………………………………………6

2.3 实验仪器简介…………………………………………………………………………………6

3 实验过程及分析………………………………………………………………………………10

3.1 实验过程………………………………………………………………………………………10

3.1.1实验前准备事项……………………………………………………………………………10

3.1.2实验进行中的操作…………………………………………………………………………10

3.1.3测IV曲线……………………………………………………………………………………12

3.1.4 测DNA过孔信号…………………………………………………………………………13

3.1.5 实验后的数据处理…………………………………………………………………………13

3.2 实验结果及分析………………………………………………………………………………13

3.2.1 实验一………………………………………………………………………………………13

3.2.2 实验二………………………………………………………………………………………17

3.2.3 实验三………………………………………………………………………………………21

3.2.4 实验四………………………………………………………………………………………22

4 结论……………………………………………………………………………………………26

5 总结与改进……………………………………………………………………………………27

5.1 实验总结………………………………………………………………………………………27

5.1.1实验前总结…………………………………………………………………………………27

5.1.2实验操作总结………………………………………………………………………………27

5.1.3实验数据处理总结…………………………………………………………………………28

5.2 实验改进………………………………………………………………………………………28

5.2.1干扰信号……………………………………………………………………………28

5.2.2进一步实验研究……………………………………………………………………………29

致谢……………………………………………………………………………………………30

参考文献………………………………………………………………………………………31

浓度梯度对生物分子通过纳米孔的影响研究

1、 绪论

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