平行四面体纳米孔道中DNA超结构的组装和离子输运特性

<正>受生物膜离子通道结构和功能的启发,人工制备固体纳米孔道门控开关器件一直备受关注[1,2].基于仿生纳米孔道的非对称离子传输性质制备的离子二极管和场效应管装置对于构建离子电路和能量转换的纳米器件至关重要[3,4].然而,仿生制备的固体纳米孔道在离子传输过程中有漏电流的存在,严重影响了固体纳米孔道应用的灵敏度和信噪比[5].针对这一问题,研究者利用DNA分子的特殊识别和自组装的功能特性,相继构筑了基于DNA和纳米孔道的智能响应体系[6,7].但在之前的研究工作中,分[8]     

仿生离子通道研究进展:从一维到二维

在生物电体系中,细胞膜中层级排列的离子通道和离子泵构成集成化的纳米尺度的离子导体,它们成为生命体系能量转换的关键结构基础.从生物离子通道上获得相关启示,通过构筑一维、二维纳米孔道来模拟生物离子通道的结构和功能,实现了可控的离子传输和能量转换.本文总结了仿生离子通道从一维直通构型到二维层状构型的发展,各自的特点、材料的制备方法,以及在仿生能量转换方面的应用.二维仿生离子通道提供了一种大规模、低成本、更为高效的纳米孔道材料制造技术,向纳米孔道材料的实用化迈出了重要一步.本文还重点介绍了二维层状材料及其构筑的二维离子通道在超滤、能量转换与存储等方面的应用.     

基于仿生智能纳米孔道的先进能源转换体系

自然界中的生命体系经过40多亿年的进化,实现了对能源的高效转换、存储和利用.特别是生物膜上的各类孔道结构在其中起着重要作用.基于仿生智能纳米通道的先进能源转换体系从生物离子通道中获取与能量转换相关的启示(例如,电鳗放电、ATP合成、视网膜、紫膜等),从原理和结构上模仿生命体系中高效能量转换的某一个侧面,通过产能材料的设计和转换器件的组装,实现机械能到电能、光能到电能、光能到化学能等不同能量形式之间的转换.我们综述了目前应用人工合成的纳米尺度孔道结构进行仿生能源转换的三个热点领域:纳米流体动能-电能转换,纳米流体反向电渗析系统和基于仿生智能纳米孔道的先进能源转换体系.基于智能纳米孔道的能源转换方法摆脱了传统发电设备所必需的机械转动装置的束缚,在可以预见的范围内,仿生产能器件的效能必将超越已有人工体系,为面向未来的能源技术的创新提供了新思路,新理论和新方法.     

Au纳米颗粒作用下的仿生纳米通道

在自然界的生物体系中,各种各样的离子通道对物质交换、能量输运等生理过程起着重要作用.用人工制备的仿生纳米器件模仿生物孔道的离子输运性质是一项非常具有挑战性的课题.通过在对称柱形聚对苯二甲酸乙二醇酯（PET）聚合物孔道中引入非对称结构,获得了一种具有高整流比的人工纳米孔道体系.通过带正电荷的2-十一烷基-1-二硫脲乙基咪唑啉季铵盐（SUDEI）在柱形纳米孔道的单面吸附,使体系具有了非对称的电荷分布和几何结构,从而具有非线性的离子输运性质,表现出较好的门控性能.Au纳米颗粒可以与SUDEI以Au-S键稳定结合,有效地减小柱孔一端的孔径,进一步提高体系的门控比,且该纳米通道体系非对称响应离子输运有很好的稳定性.     

水凝胶基仿生离子通道及其智能离子传输

离子可控传输是维持众多正常生理活动的重要基础,而实现可控离子传输的关键是生命体系中的各类蛋白质离子通道.受此启发,科研工作者开发了一系列仿生智能离子通道,实现了类似生命体中的可控离子传输.其中,基于水凝胶体系的离子通道由于其空间荷电性和三维互通特性,展现出高离子选择性和高离子通量的优点.同时,水凝胶基离子通道的生物相容性、可形变特性及稳定的离子储存特性,使其成为智能离子传输领域的研究热点之一,该类材料已被广泛应用于离子-电子电路、医疗健康、能源转化与存储以及资源与环境等领域.本文主要从水凝胶基智能离子通道的构筑方法出发,阐述了凝胶内部离子传输机制,并对其在各领域的应用进行了总结,最后对目前水凝胶基离子通道存在的问题及未来发展趋势进行了展望.     

仿生制备多级化纳米通道及其离子电流行为研究

自然界中的多级化离子通道在生命活动中发挥着至关重要的作用.生物体内的多级化离子通道包括两种类型:胞间连接通道和多级复合离子通道.研究人员以生物体内的多级化离子通道结构为模型,在仿生制备多级化纳米通道方面做了大量的研究工作.本文综述了人工多级化纳米通道的离子电流行为及其在能量转换中的应用,并展望了仿生制备的多级化纳米通道在未来的应用前景.     

聚合物基纳米通道的构筑、功能化及应用研究进展

纳米通道在生命过程中起着至关重要的作用。利用聚合物基纳米通道研究离子、分子等在通道内的输运、识别、响应及门控的仿生过程和性质,受到了科学家的广泛关注和研究。目前,构筑聚合物基纳米通道最常用方法是径迹刻蚀技术。刻蚀后的固态纳米通道具有可功能化的基团,科学家正在广泛开展探究纳米孔道功能化的方法研究。本文主要从几种聚合物的刻蚀方法及形状控制,来介绍纳米通道的构筑方法。同时,本文还总结了纳米通道功能化修饰的常用方法。最后,介绍了纳米通道在多方面的应用、未来的展望以及目前该领域存在的一些挑战。     

肽适体修饰纳米孔道对L-精氨酸的灵敏检测

氨基酸是生命之源,其中L-精氨酸(L-Arg)是生物体进行新陈代谢的一种重要氨基酸,同时也是重要的肿瘤标志物之一.因此，开发高选择性的L-Arg检测方法在生物分析领域十分重要.本文在Uniprot数据库29185个蛋白质序列中筛选出特异性结合L-Arg的多肽序列(序列为CFGHIHEGY),经ITC验证后,将其作为识别元件固定在子弹形纳米孔道尖端表面.在纳米空间限域效应下,利用多肽与L-Arg特异性结合前后构象由伸展状态向蜷缩状态的变化,调控纳米孔道离子输运特性变化,从而实现对L-Arg的选择性检测.实验结果表明,多肽修饰纳米孔道对L-Arg具有高灵敏度和高选择性,线性范围为1～100 nmol/L,检出限低至1 nmol/L.该研究为氨基酸高选择性、高灵敏检测提供了新方法,同时也为多肽修饰仿生离子通道的构建提供了新思路.     

异质膜纳米通道的构建及其应用研究

从生物体离子通道中得到启发,研究人员开发了一系列仿生纳米通道,通过对内外表面的化学修饰,实现了在仿生纳米通道受限空间内离子转运的智能调控.目前的研究主要集中在均质膜方向,均质膜单一的结构和功能限制了其进一步发展,研发制备过程简单、稳定性好和功能多样的异质膜逐渐成为研究热点.与均质膜相比,异质膜被赋予单独使用均质膜时无法...     

基于仿生膜的功能化单纳米通道在分析化学中的应用

灵感来源于蛋白质离子通道的仿生功能化单纳米通道,已逐渐成为一种成熟的单分子检测技术和离子整流器。功能化纳米通道包括两种:基因改造的蛋白质纳米通道和固体加工的纳米通道。常用的固体纳米通道有三种:在纳米氮化硅或石墨烯上用聚焦离子束(FIB)或电子束(FEB)轰击得到的纳米通道,化学腐蚀聚合物薄膜中的重金属离子轨迹得到的锥形纳米通道和拉制毛细管或激光刻蚀得到的玻璃纳米孔。相对于蛋白质纳米通道,固态的人工纳米通道具有更优越的机械稳定性,并可用于各种功能基团的修饰。经过近十年的发展,包括蛋白质纳米通道在内的各种仿生的纳米通道已广泛用于对小分子、蛋白质和聚合物等其他一些对象的定性和定量检测。本综述详细介绍了近年来国内外该领域的发展,并对未来的发展方向作了简要的展望。     

Construction and application of photoresponsive smart nanochannels

In living organisms, many biological processes are inextricably linked with light, such as the photosynthesis systems and rhodopsin. Hence, construction of light-sensitive biomimetic-nanochannels, which can realize the functions of cells and other membrane structures with high degree of spatial and temporal control, is particularly attractive and challenging. As a cornerstone of light-sensitive nanochannels, the photoresponsive materials are a big family and at their mature stage after several decades of development, which can provide different strategies to construct biomimetic photoresponsive nanochannels. In this review, we mainly summarize the construction and applications of photoresponsive nanochannels on the basis of various photoresponsive materials. The construction of photoresponsive nanochannels can be classified into four categories: photoresponsive inorganic nanochannels based on inorganic-compound-based photonic sensitive materials; photoresponsive organic nanochannels based on organic-compound-based photonic sensitive materials; photoresponsive polymers nanochannel based on photoresponsive polymers materials and potential photoresponsive nanochannels based on other photoresponsive materials. After introducing the construction of photoresponsive nanochannels, the review highlights some of the most recent applications of photoresponsive nanochannels in separation, energy conversion and storage, drug delivery and so on.     

Biomimetic Nanofluidic Diode Composed of Dual Amphoteric Channels Maintains Rectification Direction over a Wide pH Range

pH‐gated ion channels in cell membranes play important roles in the cell's physiological activities. Many artificial nanochannels have been fabricated to mimic the natural phenomenon of pH‐gated ion transport. However, these nanochannels show pH sensitivity only within certain pH ranges. Wide‐range pH sensitivity has not yet been achieved. Herein, for the first time, we provide a versatile strategy to increase the pH‐sensitive range by using dual amphoteric nanochannels. In particular, amphoteric polymeric nanochannels with carboxyl groups derived from a block copolymer (BCP) precursor and nanochannels with hydroxyl groups made from anodic alumina oxide (AAO) were used. Due to a synergistic effect, the hybrid nanochannels exhibit nanofluidic diode properties with single rectification direction over a wide pH range. The novel strategy presented here is a scalable, low‐cost, and robust alternative for the construction of large‐area membranes for nanofluidic applications, such as the separation of biomolecules.     

Construction of biomimetic smart nanochannels with polymer membranes and application in energy conversion systems

Learning from nature has inspired the creation of intelligent devices to meet the increasing needs of the advanced community and also to better understand how to imitate biology. As one of biomimetic nanodevices, nanochannels or nanopores aroused particular interest because of their potential applications in nanofluidic devices, biosensing, filtration, and energy conversions. In this review we have summarized some recent results mainly focused on the design, construction and application in energy conversion systems. Like biological nanochannels, the prepared smart artificial nanochannels fabricated by ion track-etched polymer membranes and smart molecules show a great potential in the field of bioengineering and biotechnology. And these applications can not only help people to know and understand the living processes in nature, but can also inspire scientists to study and develop novel nanodevices with better performance for the mankind.     

Development of photoresponsive supramolecular machines inspired by biological molecular systems

In the growing research area on molecular machinery, light is one of the attractive and useful stimuli source to operate synthetic molecular machines, since light allows selective operation of photoresponsive moieties without additives. We have proposed a new approach to design of photoresponsive molecular machines by interlocking mechanical motions between photoresponsive and movable units through covalent and non-covalent bonds. This approach is inspired by biological molecular machines consisting of multiple protein subunits, and potentially useful for construction of giant mechanical systems. In this review, we will introduce our concepts of the molecular design with several successful examples as well as their applications for controlling chemical events, and also glance at a semi-biological molecular machine controllable by light, which reveals a potential of biological systems for development of elaborate molecular devices.     

Biomimetic stimuli‐responsive nanochannels and their applications

Biomimetic smart nanochannels have been studied extensively to achieve the precise ionic transport compared to biological ion channels. Similar to ion channels in living organisms, biomimetic smart nanochannels can respond to various stimuli, which allows for promising applications in many fields. In this review, we mainly summarize the recent advances in the design of biomimetic stimuli‐responsive nanochannels and their potential applications including biosensors and drug delivery. Finally, an outlook on the challenges and opportunities for biomimetic stimuli‐responsive nanochannels is provided.     

Recent advance of photochromic diarylethenes-containing supramolecular systems

Photochromic diarylethenes were deemed to be one of the most promising molecular building blocks for photoresponsive materials. This review gives a brief summary to the recent progress of studies of diarylethenes in supramolecular systems, focusing on their applications in biological systems, photo-responsive mechanical materials and photo-responsive chemosensors.     

Construction and application of bioinspired nanochannels based on two-dimensional materials

With the development of nanotechnology and materials science, bioinspired nanochannels appeared by mimicking the intelligent functions of biological ion channels. They have attracted a great deal of attention in recent years due to their controllable structure and tunable chemical properties. Inspired by the layered microstructure of nacre, 2D layered materials as excellent matrix material of nanochannel come into our field of vision. Bionic nanochannels based on 2D materials have the advantages...     

Biomimetic nanochannel membrane for cascade response of borate and cis-hydroxyl compounds: An IMP logic gate device

Biomimetic cascade response of borate and cis-hydroxyl compounds in nanochannels, acted as IMP logic gates.     

Light‐Controlled Ion Transport through Biomimetic DNA‐Based Channels

Light‐controlled nanochannels are fabricated through self‐assembling azobenzene‐incorporated DNA (Azo‐DNA) strands to regulate ion transport. By switching between collapsed and relaxed states using visible and ultraviolet light alternately, the Azo‐DNA channels can be opened and closed because the conformation of Azo‐DNA changes, that is, Azo‐DNA is used as switchable controlling unit. In addition to sharing short response time and reversibility with other photoresponsive apparatuses, the Azo‐DNA‐based nanochannel system has advantages in good biocompatibility and versatile design, which could potentially be applied in light‐controlled drug release, optical information storage, and logic networks.