pH和钙离子协同控制的纳米流体门控器件  

pH and Calcium Cooperative Regulation Nanofluidic Gating Device

作　　者：许阳蕾 孟哲一[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》2016年第6期538-544,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)(No.2012CB720904);国家自然科学基金(No.21271016);'北京航空航天大学基本科研业务费-博士研究生创新基金'资助~~

摘　　要：生命体内的钙离子通道在各种生物功能调节过程及生命活动中起着至关重要的作用.模仿生物体中钙离子通道的各种功能性,构建人工智能通道,并研究通道中的钙离子输运性能成为一项非常重要的研究课题.通过重粒子轰击技术及径迹刻蚀方法在高分子聚合物薄膜上设计并制备了一种非对称的锥形多孔纳米通道.并且通过在锥形纳米通道内壁修饰功能分子O-磷酸基L-络氨酸(OPLT)使纳米通道具有p H与钙离子协同响应的功能.此体系模仿了生物体中钙离子响应的离子通道的离子输运行为,及类似二极管的离子整流特性,并表现出了稳定的离子门控特性及可逆性.当p H为5时,通道内壁修饰的OPLT中的氨基使通道内壁显正电性,通道表现为选择阴离子,而排斥阳离子的离子选择输运性能,加入钙离子后离子电流并无明显变化,此时纳米通道不具有钙离子响应性质;当p H为9时,OPLT中的磷酸根基团使通道内壁呈现负电性,通道表现出选择阳离子,而排斥阴离子的离子选择输运性能,此时向纳米系统中加入钙离子,钙离子与磷酸根离子络合,离子电流改变.即OPLT修饰的纳米通道具有p H与钙离子协同响应的性能.In living body, Ca2＋-responsive ion channels play crucial roles in many biological activities. Inspired by nature, the design and fabrication of artificial smart nanochannels system become a very significant research subject, mimicking the biological Ca^2＋-responsive signals in ion channels. In this article, by using track-etched artificial polyethylene terephthalate （PET） multiporous membrane materials and modifying intelligent molecules O-Phospho-L-tyrosine （OPLT） through chemical modification method, we demonstrate a new biomimetic artificial smart responslve ion channel system, which presents the cooperative response to pH and calcium. The nanosystem shows ion selective transport, ion gating and ion rectification property, which is similar to the property of biological Ca2＋-responsive ion channels. And the cooperative responsive property of pH and calcium in OPLT modified nanochannels was also investigated by measuring the current-voltage （I-V） curves. At a low pH value, the surface charge of the nanochannels walls is positive as a result of the amino group （NH3＋ ） of OPLT, the nanosystem attracts the anions and inhibits the cations due to electrostatic interactions between the anions passing through the nanochannels and the nanochannels cations walls, resulting in ion current rectification property. Meanwhile, aRer adding calcium to the nanosystem, no significant changes of ion current are found. The system presents no calcium responsive property. At a high pH value, the surface charge of the nanochannels walls is negative due to the phosphate group （ HPO4^2- ） of OPLT, the nanosystem shows cations-selective. ARer adding calcium to the solution, the bonding of phosphate group （ HPO4^2- ） with calcium （Ca^2＋） results in the neutralization of the surface charge in the nanochannels. This nanochannels switch the polarity of ion transport from cation-selective to non-selective, and turn from the highly conductive state to the low conductive state. The significant decline of t

关 键 词：钙离子门控 离子通道 整流性 PH响应 纳米流体 

分 类 号：TB383.1[一般工业技术—材料科学与工程]