Interfacial nanoarchitectonics for molecular manipulation and molecular machine operation

The nanoarchitectonics concept enables us to produce functional systems and materials from nanoscale units through nanotechnological approaches together with the processes including chemical syntheses, atom/molecule manipulations, self-assemblies, self-organizations, field-induced material regulations, and bio-related processes. Especially, manipulations of molecules (molecular machines) and sophisticated organization would be attractive targets in interfacial nanoarchitectonics. In this short review, we introduce several typical examples on manipulations of functional molecules and molecular machines at interfacial media. The examples are classified roughly according to driving forces of manipulations; (i) manipulations through chemical reactions and interactions; (ii) light-driven manipulations; (iii) electrically controlled manipulations; (iv) mechanical manipulations. Future possibilities of molecular manipulations at interfaces such as usages in biological systems are discussed in perspective section.     

Nanoarchitectonics from Atom to Life

Functional materials with rational organization cannot be directly created only by nanotechnology‐related top‐down approaches. For this purpose, a novel research paradigm next to nanotechnology has to be established to create functional materials on the basis of deep nanotechnology knowledge. This task can be assigned to an emerging concept, nanoarchitectonics. In the nanoarchitectonics approaches, functional materials are architected through combination of atom/molecular manipulation, organic chemical synthesis, self‐assembly and related spontaneous processes, field‐applied assembly, micro/nano fabrications, and bio‐related processes. In this short review article, nanoarchitectonics‐related approaches on materials fabrications and functions are exemplified from atom‐scale to living creature level. Based on their features, unsolved problems for future developments of the nanoarchitectonics concept are finally discussed.     

Nanoarchitectonics in combat against bacterial infection using molecular,interfacial, and material tools

Nanoarchitectonics, as a post-nanotechnology concept, is the methodology for constructing functional materials from nano-units, which bridges the gap between nanotechnology and materials science. The research accomplishes advocating nanoarchitectonics has increased dramatically as overviewed in the initial part of this review. Then, as socially impactful subjects, we exemplify nanoarchitectonics research for bacterial infections according to classifications featured with molecular tools, interfaces, and hierarchically structured materials. In particular, this review article discusses namely three kinds of antibacterial strategies: (i) new antimicrobial agents and therapeutic modalities based on nanoarchitectonics present high bactericidal efficacy against methicillin-resistant Staphylococcus aureus; (ii) antimicrobial nanoarchitectonics structures are integrated into the surface of medical devices to detach or kill approaching bacteria; (iii) the nanoarchitectonics hydrogels act as antimicrobial reservoirs to produce sustained-release antimicrobial agents for long-lasting bacterial killing.     

Layer‐by‐Layer Assembly: Recent Progress from Layered Assemblies to Layered Nanoarchitectonics

As an emerging concept for the development of new materials with nanoscale features, nanoarchitectonics has received significant recent attention. Among the various approaches that have been developed in this area, the fixed‐direction construction of functional materials, such as layered fabrication, offers a helpful starting point to demonstrate the huge potential of nanoarchitectonics. In particular, the combination of nanoarchitectonics with layer‐by‐layer (LbL) assembly and a large degree of freedom in component availability and technical applicability would offer significant benefits to the fabrication of functional materials. In this Minireview, recent progress in LbL assembly is briefly summarized. After introducing the basics of LbL assembly, recent advances in LbL research are discussed, categorized according to physical, chemical, and biological innovations, along with the fabrication of hierarchical structures. Examples of LbL assemblies with graphene oxide are also described to demonstrate the broad applicability of LbL assembly, even with a fixed material.     

Liquid interfacial nanoarchitectonics: Molecular machines,organic semiconductors,nanocarbons, stem cells,and others

The concept of nanoarchitectonics has been proposed as an extensional development of nanotechnology through fusions with material science and the other fields. In nanoarchitectonics, nano-units of atoms, molecules, and nanomaterials are architected into construction of functional material systems. In order to assemble intended structures or hierarchical structures from nano-units, it is more useful to confine nano-units at the interface. In addition, nanoarchitectonics is expected to output functions by harmonizing many units in dynamic environments. However, the liquid interfaces still have lots of unexplored matters in nanoscale because supports by advanced apparatus and techniques in nanotechnology are not always available. Specifically, this review paper summarizes examples of research on molecular manipulation, molecular arrangement and assembly, materials synthesis, and life manipulation at the liquid interface. These examples demonstrate that the liquid interface enables the control of dynamic functions of various size regions, from molecular-level phenomena such as the control of molecular machines to techniques of living creature size such as the control of stem cell differentiation. Liquid interfaces are very useful environments for controlling dynamic functions for a wide range of targets and would have tremendous potential in terms of functional exploration. The great potential of nanoarchitectonics at the liquid interface and the challenges to be solved in the future are also discussed.     

Nanoarchitectonics beyond Self‐Assembly: Challenges to Create Bio‐Like Hierarchic Organization

Incorporation of non‐equilibrium actions in the sequence of self‐assembly processes would be an effective means to establish bio‐like high functionality hierarchical assemblies. As a novel methodology beyond self‐assembly, nanoarchitectonics, which has as its aim the fabrication of functional materials systems from nanoscopic units through the methodological fusion of nanotechnology with other scientific disciplines including organic synthesis, supramolecular chemistry, microfabrication, and bio‐process, has been applied to this strategy. The application of non‐equilibrium factors to conventional self‐assembly processes is discussed on the basis of examples of directed assembly, Langmuir–Blodgett assembly, and layer‐by‐layer assembly. In particular, examples of the fabrication of hierarchical functional structures using bio‐active components such as proteins or by the combination of bio‐components and two‐dimensional nanomaterials, are described. Methodologies described in this review article highlight possible approaches using the nanoarchitectonics concept beyond self‐assembly for creation of bio‐like higher functionalities and hierarchical structural organization.     

Nanoarchitectonic‐Based Material Platforms for Environmental and Bioprocessing Applications

The challenges of pollution, environmental science, and energy consumption have become global issues of broad societal importance. In order to address these challenges, novel functional systems and advanced materials are needed to achieve high efficiency, low emission, and environmentally friendly performance. A promising approach involves nanostructure‐level controls of functional material design through a novel concept, nanoarchitectonics. In this account article, we summarize nanoarchitectonic approaches to create nanoscale platform structures that are potentially useful for environmentally green and bioprocessing applications. The introduced platforms are roughly classified into (i) membrane platforms and (ii) nanostructured platforms. The examples are discussed together with the relevant chemical processes, environmental sensing, bio‐related interaction analyses, materials for environmental remediation, non‐precious metal catalysts, and facile separation for biomedical uses.     

From self-organizing polymers to nanohybrid and biomaterials

Block copolymers form a large number of superlattices with characteristic dimensions in the range of a few nanometers up to several micrometers by self-organization. The interplay of supramolecular physics and chemistry opens up new approaches to the production of inorganic, organic, and biological structures and to their integration into functional units. Possible applications in the fields of materials science and molecular biology are being investigated. Block copolymers find numerous applications from the production of inorganic nanoparticles (metals, semiconductors, magnets) and mesoporous materials up to take-up/release systems in chemo- and gene therapy.     

Nanoarchitectonics on Electrosynthesis and Assembly of Conjugated Metallopolymers

In contrast to edge-on and face-on orientations, end-on uniaxial conjugated polymers have the theoretical possibility of providing a macroscopic crystalline film. However, their fabrication is insurmountable due to sluggishly thermodynamic equilibrium states. Herein, we report the programmatic pathway to fabricate nanoarchitectonics on end-on uniaxial conjugated metallopolymers by surface-initiated simultaneous electrosynthesis and assembly. Self-assembled monolayer (SAM) with bottom-up oriented electroactive molecules as a temple allows orientation, stacking, and reactive addition of monomers triggered by switching alternative redox reactions as well as crystallization of small molecules. Repeating the same reaction can repair the unreactive site on the SAM and dynamically and statistically ensure maximum iterative coverage with ideal linear coefficients between optical or electrical responses and iterative times. The resulting nanoarchitectonics on uniaxially assembled end-on polymers over centimeter-sized areas have a subnanometer-uniform morphology and exhibit ultrahigh modulus as well as an inorganic indium tin oxides and the highest conductance among conjugated molecular monolayers. Their memristive devices provide quantitative electrical and optical responses as a function of molecular length, bias, and iterative junctions. Precise processing of nanoarchitectonics as an electrically assisted assembly or printing technique can present sophisticated optoelectric functions and dimensional batch-to-batch consistency for micro-sized organic materials and electronics.     

Properties and applications of precision oligomer materials; where organic and polymer chemistry join forces

Precise oligomeric materials constitute a growing area of research with implications for various applications as well as fundamental studies. Notably, this field of science which can be termed macro-organic chemistry, draws inspiration from both traditional polymer chemistry and organic synthesis, combining the molecular precision of organic chemistry with the materials properties of macromolecules. Discrete oligomers enable access to unprecedented materials properties, for example, in self-assembled structures, crystallization, or optical properties. The degree of control over oligomer structures resembles many biological systems and enables the design of materials with tailored properties and the development of fundamental structure–property relationships. This Review highlights recent developments in macro-organic chemistry from synthetic concepts to materials properties, with a focus on self-assembly and molecular recognition. Finally, an outlook for future research directions is provided.     

Crystal engineering: a holistic view

Crystal engineering, the design of molecular solids, is the synthesis of functional solid-state structures from neutral or ionic building blocks, using intermolecular interactions in the design strategy. Hydrogen bonds, coordination bonds, and other less directed interactions define substructural patterns, referred to in the literature as supramolecular synthons and secondary building units. Crystal engineering has considerable overlap with supramolecular chemistry, X-ray crystallography, materials science, and solid-state chemistry and yet it is a distinct discipline in itself. The subject goes beyond the traditional divisions of organic, inorganic, and physical chemistry, and this makes for a very eclectic blend of ideas and techniques. The purpose of this Review is to highlight some current challenges in this rapidly evolving subject. Among the topics discussed are the nature of intermolecular interactions and their role in crystal design, the sometimes diverging perceptions of the geometrical and chemical models for a molecular crystal, the relationship of these models to polymorphism, knowledge-based computational prediction of crystal structures, and efforts at mapping the pathway of the crystallization reaction.     

Molecular manipulation of solid state structure: influences of organic components on vanadium oxide architectures

Among the inorganic materials enjoying widespread contemporary interest, the metal oxide based solid phases occupy a prominent position by virtue of their applications to catalysis, sorption, molecular electronics, energy storage, optical materials and ceramics. The diversity of properties associated with these materials reflects the chemical composition, which allows variations in covalency, geometry and oxidation states, and the crystalline architecture, which may provide different pore structures, coordination sites, or juxtapositions of functional groups. Despite such fundamental and practical significance, the design of the structure of such materials remains a challenge in solid state chemistry. While organic materials have been synthesized which self-assemble into ordered arrays at low temperature and which exhibit molecular recognition and biomimetic activity, the ability to synthesize inorganic materials by rational design remains elusive. Small, soluble molecular building blocks with well-defined reaction chemistries which allow their low-temperature assembly into crystalline solid state inorganic materials are not well known. However, the existence of naturally occurring, structurally complex minerals establishes that hydrothermal synthesis can provide a low temperature pathway to produce open-framework and layered metastable structures utilizing inorganic starting materials. Thus, hydrothermal conditions have been used to prepare microporous tetrahedral framework solids that are capable of shape-selective absorption, like zeolites and aluminophosphates, and more recently in the preparation of complex solid arrays of the M/O/PO³⁻₄ and M/O/RPO²⁻₃ systems (M=V and Mo). The hydrothermal technique may be combined with the introduction of organic components which may act as charge compensating groups, space-filling units, structure directing agents, templates, tethers between functional groups, or conventional ligands in the preparation of inorganic/organic composites.In the past decade, this general strategy has been exploited in the evolution of a family of vanadium oxides incorporating structure-directing organic or secondary-metal organic subunits, which are the topic of this review. The synthetic approach to novel vanadium oxide solids occupies the interface between materials science and coordination chemistry. The emerging theme focuses on the association of an organic component, acting as a ligand, tether, or structure directing moiety, with the inorganic framework of the solid to provide unique composites. While some organic components may limit the size of inorganic cluster subunits of a solid by passivating the surface of an aggregate through capping, such ligands may also serve to link inorganic subunits into complex networks. In other cases, the organic subunit, rather than participating as a covalently bound unit of the framework, acts in a structure directing role, producing amphiphilic materials whose structures are determined by hydrophobic–hydrophilic interactions. This latter feature is reminiscent of the factors influencing biomineralization, a field which may prove relevant to the development of new strategies for the controlled synthesis of organized inorganic and organic/inorganic composite materials. These various approaches to the “design” of inorganic solids are discussed and assessed in terms of the new structural types recently observed in the vanadium oxide chemistry.     

Recent progress of core-substituted naphthalenediimides: highlights from 2010

Core-substituted naphthalenediimides (cNDIs) are rapidly emerging as a powerful strategy to create functional nanomaterials and their implications in biological and supramolecular chemistry are significant. Recent developments in the synthesis of cNDIs have allowed several groups to probe the function of this interesting class of dye molecules in a molecular and supramolecular sense. Core-substitution of the NDI can be seen as an opportunity to extend the planar, rigid core and could be used to prepare novel structures for applications in organic, biosupramolecular chemistry, biomedicine, materials science and organic solar cells. In this Emerging Area, we provide up-to-date recent progress in the field of cNDIs. We begin with a general discussion and the applications of cNDIs in the field of supramolecular chemistry i.e. generation of nanostructures such as vesicles and nanotubes etc., and we also discuss advances in artificial photosynthesis. Following this is a section on their implications in the field of sensors, particularly DNA intercalation, anion sensing and NDI based pH sensors. Finally, we explore the recent development of cNDIs in organic solar cell applications. We conclude with our views on the prospects of cNDIs in future research.     

High-tech applications of self-assembling supramolecular nanostructured gel-phase materials: from regenerative medicine to electronic devices

It is likely that nanofabrication will underpin many technologies in the 21st century. Synthetic chemistry is a powerful approach to generate molecular structures that are capable of assembling into functional nanoscale architectures. There has been intense interest in self-assembling low-molecular-weight gelators, which has led to a general understanding of gelation based on the self-assembly of molecular-scale building blocks in terms of non-covalent interactions and packing parameters. The gelator molecules generate hierarchical, supramolecular structures that are macroscopically expressed in gel formation. Molecular modification can therefore control nanoscale assembly, a process that ultimately endows specific material function. The combination of supramolecular chemistry, materials science, and biomedicine allows application-based materials to be developed. Regenerative medicine and tissue engineering using molecular gels as nanostructured scaffolds for the regrowth of nerve cells has been demonstrated in vivo, and the prospect of using self-assembled fibers as one-dimensional conductors in gel materials has captured much interest in the field of nanoelectronics.     

Supramolecular DNA assembly

The powerful self-assembly features of DNA make it a unique template to finely organize and control matter on the nanometre scale. While DNA alone offers a high degree of fidelity in its self-assembly, a new area of research termed 'supramolecular DNA assembly' has recently emerged. This field combines DNA building blocks with synthetic organic, inorganic and polymeric structures. It thus brings together the toolbox of supramolecular chemistry with the predictable and programmable nature of DNA. The result of this molecular partnership is a variety of hybrid architectures, that expand DNA assembly beyond the boundaries of Watson-Crick base pairing into new structural and functional properties. In this tutorial review we outline this emerging field of study, and describe recent research aiming to synergistically combine the properties inherent to DNA with those of a number of supramolecular scaffolds. This ultimately creates structures with numerous potential applications in materials science, catalysis and medicine.     

Nanoscale metal-organic materials

Metal-organic materials are found to be a fascinating novel class of functional nanomaterials. The limitless combinations between inorganic and organic building blocks enable researchers to synthesize 0- and 1-D metal-organic discrete nanostructures with varied compositions, morphologies and sizes, fabricate 2-D metal-organic thin films and membranes, and even structure them on surfaces at the nanometre length scale. In this tutorial review, the synthetic methodologies for preparing these miniaturized materials as well as their potential properties and future applications are discussed. This review wants to offer a panoramic view of this embryonic class of nanoscale materials that will be of interest to a cross-section of researchers working in chemistry, physics, medicine, nanotechnology, materials chemistry, etc., in the next years.     

分子烙印技术在分析化学中的应用

分子烙印技术是一种制备具有特定选择性和亲合性的分子识别材料的技术。它在烙印分子存在的情况下,功能性单体与交联剂共聚制得高交联的聚合物网络,移去烙印分子后就得到了对烙印分子记忆效应的分子烙印聚合物。它在分析化学,催化和有机合成等领域都具有应用价值。该文主要介绍了烙印聚合物在分析化学中的应用研究,着重于它在色谱技术中的应用,尤其是在毛细管电色谱中的应用。最后对该技术的发展前景进行了讨论。     

Peptides as New Smart Bionanomaterials: Molecular‐Recognition and Self‐Assembly Capabilities

Biomolecules express exquisite properties that are required for molecular recognition and self‐assembly on the nanoscale. These smart capabilities have developed through evolution and such biomolecules operate based on smart functions in natural systems. Recently, these remarkable smart capabilities have been utilized in not only biologically related fields, but also in materials science and engineering. A peptide‐screening technology that uses phage‐display systems has been developed based on this natural smart evolution for the generation of new functional peptide bionanomaterials. We focused on peptides that specifically bound to synthetic polymers. These polymer‐binding peptides were screened by using a phage‐display peptide library to recognize nanostructures that were derived from polymeric structural features and were utilized for possible applications as new bionanomaterials. We also focused on self‐assembling peptides with β‐sheet structures that formed nanoscale, fibrous structures for applications in new bottom‐up nanomaterials. Moreover, nanofiber‐binding peptides were also screened to introduce the desired functionalities into nanofibers without the need for additional molecular design. Our approach to construct new bionanomaterials that employ peptides will open up excellent opportunities for the next generation of materials science and technology.     

Molecular-Based Design of Microporous Carbon Nanosheets

Microporous carbons afford high surface areas, large pore volumes, and good conductivity, and are fascinating over a wide range of applications. Traditionally synthesized microporous carbon materials usually suffer from some limitations, such as poor accessibility and slow mass transport of molecules due to the micrometer-scale diffusion pathways and space confinement imposed by small pore sizes. Two-dimensional microporous carbon materials, denoted as microporous carbon nanosheets (MCNs), possess nanoscale thickness, which allows fast mass and heat transport along the z axis; thus overcoming the drawbacks of their bulk counterparts. Herein, recent breakthroughs in the synthetic strategies for MCNs are summarized. Three typical methods are discussed in detail with several examples: pyrolysis of organic precursors with 2D units, a templating method that uses wet chemistry, and the molten salt method. Among them, molecular-based assembly of MCNs in the liquid phase shows more controllable morphology, thickness, and pore size distribution. Finally, challenges in this research area are discussed to inspire future explorations.     

卟啉及卟啉衍生物的应用

近年来,卟啉及卟啉衍生物在显色反应、分子识别、催化合成反应等领域中有很广泛的应用。文章就卟啉及卟啉衍生物在分析化学、生命科学和化学合成方面的研究发展作一简要介绍,并提出卟啉化合物今后的发展方向。