摘要
Based on the noncovalent functionalization of ferrocene-grafted polyethylenimine （PEI-Fc） and carbon nanotubes （CNTs）, CNT bundles are exfoliated by PEI-Fc solution and thus form stable compounds PEI-Fc@CNTs, which is used to construct the PEI-Fc@CNTs/DNA multilayers through layer-by-layer assembly. The multilayers show a highly uniform and homogeneous characteristic, which significantly improve the electrical property of the multilayers. Upon the oxidation electrical potential, the ferrocene groups are switched from reduction state （[Fe（C5H5）2]） to oxidation state （[Fe（C5H5）2]^＋）, leading to change of microenvironments＇ charge density, resulting in swelling of the multilayers and a final degree of swelling of 37 % and the decrease of multilayer stiffness. We maintain that electrochemical control over the swelling behavior of multilayers could have important implications for responsive coatings of nanoscale devices, including mechanically tunable surfaces which are used to modulate cellular activities and control drug delivery.
利用二茂铁分子修饰的聚乙烯亚胺(PEI-Fc)与碳纳米管(CNTs)之间的特殊非共价键作用,能够制备稳定的PEI-Fc@CNTs溶液,并由此与DNA进行层层静电组装.组装制备的(PEI-Fc@CNTs/DNA)多层膜结构均一,并显示出增强的电化学性能.在氧化电势下,二茂铁分子将从还原态([Fe(C5H5)2])转变为氧化态([Fe(C5H5)2]+),导致多层膜内电荷密度的改变.由此,多层膜能够达到37%的溶胀,硬度随之下降.通过电化学手段调控溶胀性能的多层膜能够应用于纳米器件涂层领域,实现对细胞行为的调控或药物的控释.
基金
supported by the National Natural Science Foundation of China(21174126,51333005,21374095)
the National Basic Research Program of China(2011CB606203)
Research Fund for the Doctoral Program of Higher Education of China(20110101110037,20120101130013)
the Qianjiang Excellence Project of Zhejiang Province(2013R10035)
International Science&Technology Cooperation Program of China(2014DFG52320)
