纳尺度下生物溶液的流变行为的研究

田煜++葛世荣++罗勇++刘大猛

摘 要：基于納米孔的第三代基因测序仪或者相关的关键技术对于保护我国自己的基因资源具有战略意义。要实现该类基因测序技术，目前存在的主要问题：一是DNA分子过孔速度的控制，生物分子在纳流体环境下流动规律尚没有建立—无法有效控制DNA过孔速度，目前过孔速度过快；一是四种碱基与生物纳米孔壁相互作用机理尚不清晰—生物信息提取与辨识困难，也由于过孔速度过快，通过测试得到的过孔电流的特征来识别过孔的碱基还具有较大困难。围绕项目的关键问题，在该课题中，拟通过深入探讨DNA过纳米孔的关键问题离子电流的形成与调控机理，DNA分子与壁面的特异性作用来促进项目目标的完成。本年度主要开展了：（1）DNA碱基的特异性作用的研究，包括银纳米粒子与DNA碱基间的相互作用研究，胞嘧啶（C，Cytosine）与鸟嘌呤（G，Guanine）之间的特异性作用；（2）纳米孔离子电流形成机理的研究，包括纳米孔离子电流的理论研究和纳米孔离子电流的实验研究；（3）纳米力学测试方法的建立与探索，包括受限条件下的纳米力学测试方法、不同材料在受限条件下的法向力-位移曲线、生物溶液环境下进行了纳米压痕仪的操作调试、基于金表面吸附DNA碱基的力-位移曲线的测量表征表面结合力和基于拉曼光谱和荧光谱（PL）研究DNA碱基在单层MoS2上的吸附。

关键词：纳米尺度 表面力 离子电流 流变

Research on Rheological Properties of Bio-solutions at Nanoscale-annual Report

Tian Yu1 Ge Shirong2 Luo Yong2 Liu Dameng1

（1.Tsinghua University；2. China University of Mining and Technology）

Abstract：Nanopore based third-generation gene sequencing instrument and related key technologies is of strategic significance for the protection of genetic resources of China. To realize such gene sequencing technology， currently the main problems exist are as following. The speed control of DNA molecule through the nanopore， biological molecules in the fluid environment of salt solution has not been established yet. An effectively control of the speed of DNA has not been realized yet. The present speed is too fast. The interaction mechanism of four bases and nanopore wall is not clear， leading to difficulty in biological information extraction and identification. Aiming at the final goal of the whole project， in this project， formation and regulation study of ionic current during the DNA through the nanopore， and the specific interfaction between DNA molecules with the wall are studied to promote the project goals. This year， we have carried out studies of （1）DNA nucleotide specificity， including silver nanoparticles interaction with DNA bases ， cytosine （C， Cytosine） and guanine （G， Guanine） interactions； （2）Formation mechanism of ion current through nanopore， including theoretical and experimental researches； （3）The establishment of nanomechanical testing methods and exploration the mechanical performance， including confined nano-mechanical testing methods， biological solution effect on the operation of nanoindentation test， force - displacement curve measurement based on the gold surface adsorption of DNA bases， surface adhesion and Raman spectroscopy and fluorescence spectroscopy based （PL） studies of DNA bases in a single layer adsorption on MoS2.

Key Words：Nanoscale； Surface force； Ionic current； Rheology