使用原子力显微镜观察DNA与PEI的层层自组装过程  

AFM Observation of the Change of Surface Morphology during Layer-by-layer Self-assembly of DNA and PEI

作　　者：田艳芝[1] 李艳丽[1] 姜勇[1] 

机构地区：[1]东南大学化学化工学院,南京211189

出　　处：《高分子学报》2014年第4期447-454,共8页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号21174029);教育部留学回国人员科研启动基金资助项目

摘　　要：选择了DNA与聚乙烯亚胺(PEI)进行相互作用,使用AFM直观地观察DNA与PEI层层自组装时其分子形貌的变化过程,总结了自组装过程中薄膜表面粗糙度的变化规律.同时详细地分析了离子浓度、DNA浓度、基底和固定方法对层层自组装膜的影响,以此来探讨DNA与PEI之间的相互作用机理.研究结果表明上述因素都会对膜的形貌产生影响,其中以云母作为基底,PEI处理基底表面后,再进行交替组装时,膜的表面粗糙度变化呈现出锯齿状的增长趋势,而用其他方法会影响膜的形貌以及粗糙度的变化规律.Negatively-charged DNA and positively-charged polyethylenimine （PEI） were selected to form layer-by-layer self-assembly films on different substrates. The changes of film morphologies and surface roughness during the assembly processes were observed and measured in detail by AFM at a molecule level. The influences of DNA concentration, ion concentration, substrate and modification method on the self-assembly films were analyzed in detail in order to understand the interaction between DNA and PEI. The results show that all the above factors affect the surface morphologies and roughness of the DNA/PEI films. It was found when the DNA/PEI film was self-assembled on mica surface modified by PEI,the increase of surface roughness followed a zigzag pattern with increasing the number of layers. The study may help us understand the molecular mechanism of layer-by-layer self-assembly.

关 键 词：脱氧核糖核酸(DNA) 聚乙烯亚胺(PEI) 层层自组装 原子力显微镜(AFM) 

分 类 号：O641.3[理学—物理化学]