基于纳米通道的生物分子检测及影响因素研究

发布时间：2018-11-13 09:08

【摘要】：纳米通道是指直径在0.1-100nm的孔或管道状结构,在微尺度下其具有较为出色的结构稳定性、热稳定性、优异的化学及光学等性质,故其在各大科研领域具有潜在的应用价值。尤其是研究纳米通道技术在生物分子检测方面的应用意义重大,国内外利用纳米通道对特定蛋白质大分子进行分析检测的工作已经大量展开,但是实验环境条件对生物分子在纳通道内运动的影响仍然有较多的科研价值。因此,在不同温度及粘度的电解质溶液下,研究被测蛋白质分子在纳米通道中的迁移速度及通量,本文开展了以下几个方面的工作：1.利用被测蛋白质分子通道纳米通道时对电流的阻塞作用,设计并搭建生物分子检测装置,调试实验仪器及搭建实验平台,实现通过记录离子电流的变化来检测被测粒子的过孔情况,达到对蛋白质分子检测的目的。研究环境温度对羊抗人IgG粒子迁移过孔的影响,记录不同实验温度下IgG粒子引起的电流变化情况,发现实验温度影响离子电流的回升拐点值。建立一个合理的模型对实验现象进行定性的解释,通过编写程序模拟IgG粒子的过孔情况,初步验证了实验电流变化趋势。2.研究电解质溶液粘度和纳米孔两侧浓度梯度对羊抗人IgG和牛血清白蛋白BSA迁移过孔运动的影响。溶液的粘度影响被测粒子运动时所受的粘滞阻力,增大溶液粘度有效地延长其在溶液内的运动速度,从而减少单位时间内过孔的粒子数。由于IgG与BSA具有不同形态尺寸及表面电荷密度,所以溶液粘度对二者的影响效果不同。同时在纳米孔两侧建立浓度梯度,由于浓度梯度改变纳米孔内双向电渗流的作用结果及纳米孔附近电势,从而影响纳米孔对被测粒子的捕捉率及被测粒子在纳米通道内的迁移时间。3.制作一种基于氮化硅纳米孔与聚碳酸酯纳米孔阵列的复合芯片,被测生物分子过孔引起的离子电流改变将会被记录并分析,分别在多通道和混合通道下检测过孔粒子所引起的离子电流降幅。在混合通道下,生物分子的过孔信息可以通过分析电流降幅和阻塞信号的时间来获取,并且可以通过改变复合膜上有效纳米孔的个数来调控电流降幅的出现频率,而这一结果表明基于微孔径与纳米孔阵列的混合纳流体检测芯片在生物分子的检测方面有潜在的优势。综上所述,本文研究了实验温度、电解质溶液及复合纳米通道对生物分子迁移通过纳米孔的影响,从而为利用纳米通道实现对特定生物分子的检测奠定基础。
[Abstract]:Nanochannels refer to the pore or pipe-like structures with diameter in 0.1-100nm, which have excellent structural stability, thermal stability, excellent chemical and optical properties at microscale. Therefore, it has potential application value in various scientific research fields. Especially, the research on the application of nano-channel technology in biomolecules detection is of great significance. The work of analyzing and detecting specific protein macromolecules by using nano-channels at home and abroad has been carried out in a large number. However, the effects of experimental conditions on the movement of biomolecules in the nanochannels are still of great scientific value. Therefore, under different temperature and viscosity of electrolyte solution, the migration speed and flux of protein molecules in nanowires were studied. The following work was carried out in this paper: 1. Using the blocking effect of the protein molecular channel to the current, we design and build the biomolecular detection device, debug the experimental instrument and build the experimental platform. The change of ion current can be recorded to detect the pore crossing of the tested particles, and the detection of protein molecules can be achieved. The effect of ambient temperature on the migration of sheep anti-human IgG particles was studied. The changes of current induced by IgG particles were recorded at different experimental temperatures. It was found that the experimental temperature affected the recovery of ion current at the inflection point. A reasonable model is established to explain the experimental phenomena qualitatively. The experimental current variation trend is preliminarily verified by programming to simulate the IgG particle passing through the hole. 2. The effects of the viscosity of electrolyte solution and the gradient of concentration on the migration of sheep anti-human IgG and bovine serum albumin (BSA) BSA were studied. The viscosity of the solution affects the viscosity resistance of the measured particles, increases the viscosity of the solution and effectively prolongs its velocity in the solution, thus reducing the number of particles passing through the pore in a unit time. Because IgG and BSA have different shape size and surface charge density, the effect of solution viscosity on them is different. At the same time, the concentration gradient was established on both sides of the nano-pore. The effect of bidirectional electroosmotic flow in the nano-pore and the potential near the nano-pore were changed due to the change of the concentration gradient. Thus, the trapping rate of the measured particles and the migration time of the tested particles in the nanorods were affected by the nanoparticles' trapping rate and the migration time of the tested particles in the nanoparticles. A composite chip based on silicon nitride nano-pore array and polycarbonate nano-pore array is fabricated. The ion current changes caused by the pore crossing of the measured biomolecules will be recorded and analyzed. The ion current decreases caused by porous particles were detected in multichannel and mixed channels, respectively. In the mixed channel, the information about the pore passage of biomolecules can be obtained by analyzing the current drop and the time of blocking signal, and the frequency of the current drop can be controlled by changing the number of effective nano-pores on the composite film. The results show that the hybrid nano-fluid detection chip based on micropore and nano-pore array has potential advantages in the detection of biomolecules. To sum up, the effects of experimental temperature, electrolyte solution and composite nanochannels on the migration of biomolecules through nano-pores are studied in this paper, which lays a foundation for the detection of specific biomolecules by using nanochannels.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1

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