pH-温度协同响应的纳米门控器件  

pH-Temperature Cooperative Dual-Responsive Nanogating Device

作　　者：周迪[1] 孟哲一[1] 张明辉[1] 翟锦[1] 

机构地区：[1]北京航空航天大学化学与环境学院仿生智能科学与技术教育部重点实验室,北京100191

出　　处：《化学学报》2015年第7期716-722,共7页Acta Chimica Sinica

基　　金：国家重点基础研究发展规划项目(973项目)(Nos.2011CB935704;2012CB720904);国家自然科学基金(Nos.21271016;91333120)的资助~~

摘　　要：自然界中的生物孔道在生命过程中具有重要的意义,在人工制备的仿生纳米器件上模仿生物孔道的离子输运性质是一项具有挑战性的课题.我们制备了一种基于人工聚合物薄膜的纳米门控器件,这种纳米门控器件的离子输运性质可以通过调节体系的pH和温度来调控.通过在人工聚合物薄膜上修饰功能分子聚赖氨酸(poly-L-Lysine)得到的门控器件能够模拟生物体中生物孔道的典型离子输运行为,其离子输运性能受体系pH的控制,可以通过调节体系的pH而限制纳米门控器件的导通方向.同时,在一定pH条件下调整体系温度也能够对离子输运性能产生影响,而在其他pH条件下,温度则不会对体系的离子输运性能产生明显的影响,即这种基于人工聚合物薄膜的纳米门控器件具有对pH和温度的协同响应性能.Inspired by natural biological ion channels, artificial nartochannels that can respond to external stimuli have been attracting much interests in recent years. However, design of the artificial nanochannel mimicking the organism functions and sensitive to complex signals remains one large challenge for current technique. In this work, we experimentally demonstrate a novel biomimetic nanogating device which displays advanced features of dual-stimuli cooperative respond. This feature originates from the combination of fixed charge and the cooperative configuration change of the immobilized functionaliza- tion molecule. The mentioned nanogating device is designed based on artificial polyethylene terephthalate （PET） membrane. We utilize the well-developed ion track-etching technique to produce conical nanocharmel, which is an important component of the gating device. After soaking in water overnight, the asymmetrical nanochannel distributed between membrane surfaces is modified with poly-L-lysine through two-steps chemical modification method. The immobilized amphoteric chains can exert influence on the inner surface charges due to the pH-sensitive moieties. At low pH values, the amino groups are posi- tively charged as a result of protonation. Changing the experimental pH from acidic to alkaline values, a significant decrease in positive charges and the deprotonated carboxyl group with negative charges can be observed. The ion transportation prop- erties of the nanochannels can be investigated by measuring the current-voltage （/-I1） characteristics. This phenomenon al- lows for switching the polarity of ion transport from anion-selective to cation-selective by controlling solution pH. The di- ode-like behavior is quantified by measuring the current rectification ratios. A definite plus is the existence of different con- figurations of the polymer chains. Poly-L-lysine adopts different conformation when the external pH and temperature change. At pH lower than pKa of poly-L-lysine, the polymer chain mainly ado

关 键 词：纳米门控 纳米通道 离子通道 整流性 纳流体二极管 

分 类 号：O631.3[理学—高分子化学] TB383.1[理学—化学]