納尺度下生物溶液的流變行為的研究

田煜++葛世榮++羅勇++劉大猛

摘 要：基于納米孔的第三代基因測序儀或者相關的關鍵技術對于保護我國自己的基因資源具有戰略意義。要實現該類基因測序技術，目前存在的主要問題：一是DNA分子過孔速度的控制，生物分子在納流體環境下流動規律尚沒有建立—無法有效控制DNA過孔速度，目前過孔速度過快；一是四種堿基與生物納米孔壁相互作用機理尚不清晰—生物信息提取與辨識困難，也由于過孔速度過快，通過測試得到的過孔電流的特征來識別過孔的堿基還具有較大困難。圍繞項目的關鍵問題，在該課題中，擬通過深入探討DNA過納米孔的關鍵問題離子電流的形成與調控機理，DNA分子與壁面的特異性作用來促進項目目標的完成。本年度主要開展了：（1）DNA堿基的特異性作用的研究，包括銀納米粒子與DNA堿基間的相互作用研究，胞嘧啶（C，Cytosine）與鳥嘌呤（G，Guanine）之間的特異性作用；（2）納米孔離子電流形成機理的研究，包括納米孔離子電流的理論研究和納米孔離子電流的實驗研究；（3）納米力學測試方法的建立與探索，包括受限條件下的納米力學測試方法、不同材料在受限條件下的法向力-位移曲線、生物溶液環境下進行了納米壓痕儀的操作調試、基于金表面吸附DNA堿基的力-位移曲線的測量表征表面結合力和基于拉曼光譜和熒光譜（PL）研究DNA堿基在單層MoS2上的吸附。

關鍵詞：納米尺度 表面力 離子電流 流變

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