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Assembly of distinct types of species, particularly possessing anisotropic configurations, is the premise to broaden structural diversity and explore materials' collective properties. However, it remains a great challenge to programmably cocrystallize manifold anisotropic nanoparticles with the desired assembly mode, because it requires not only the complementarity of both sizes and shapes but also the control over their directional interactions. Here, by introducing DNA origami technique into lattice engineering, we synthesize two types of DNA nano-objects with different symmetries and program the heterogeneous functional patches precisely on their surfaces with nanometer-level precision, which could guide further assembly of these nano-objects. We show that these anisotropic DNA nano-objects could be cocrystallized along specified modes via modulating the combination of surface patches. The highly ordered DNA crystals were thoroughly evidenced by techniques including small-angle X-ray scattering and electron microscopy after careful encapsulation of a thin layer of silica on these DNA nano-objects. Our strategy endows distinct shapes of organic DNA origami structures with regulation features to control the sophisticated modes of cocrystallization of these diverse components, laying a foundation for designing and fabricating customized three-dimensional structures with given optical and mechanical properties.

The creation of an artificial solid-state ion pump that mimics the delicate ion transport behaviors of a biological protein-based ion pump is drawing more and more research attention due to its potential applications in energy conversion, biosensor, and desalination. However, the reported bioinspired double-gated ion pump systems are generally very primary and can only realize nonselective ion pumping functions with no directionality and uncontrollable ion gating functions, which are far from their biological counterparts. To make the bioinspired device "smart" in a real sense, the implementation of high-level selectivity and directionality in the ion pumping process, while achieving great controllability in the ion gating process, is a necessity. Here, we developed a bioinspired heterogeneous ion pump membrane by combining block copolymer membrane sacrificial coating and plasma grafting technique. The system has unidirectional selective ion pumping and controllable ion gating properties. The introduction of asymmetric ionic group distribution is the key reason for its novel transport behaviors. Such a heterogeneous ion pump could not only provide a basic platform that potentially sparks further efforts to simulate the smart ion transport processes in living bodies but also promote the application of artificial nanofluidic devices in energy conversion, water treatment, and biosensing.

The low solubility of gases in aqueous solution is the major kinetic limitation of reactions that involve gases. To address this challenge, we report a nanochannel reactor with joint gas–solid–liquid interfaces and controlled wettability. As a proof of concept, a porous anodic alumina (PAA) nanochannel membrane with different wettability is used for glucose oxidase (GOx) immobilization, which contacts with glucose aqueous solution on one side, while the other side gets in touch with the gas phase directly. Interestingly, it is observed that the O2 could participate in the enzymatic reaction directly from gas phase through the proposed nanochannels, and a hydrophobic interface is more favorable for the enzymatic reaction due to the rearrangement of GOx structure as well as the high gas adhesion. As a result, the catalytic efficiency of GOx in the proposed interface is increased up to 80-fold compared with that of the free state in traditional aqueous air-saturated electrolyte. This triphase interface with ...

Artificial nanochannels, inheriting smart gating functions of biological ion channels, promote the development of artificial functional nanofluidic devices for high-performance biosensing and electricity generation. However, gating states of the artificial nanochannels have been mainly realized through chemical modification of the channels with responsive molecules, and their gating states cannot be further regulated once the nanochannel is modified. In this work, we employed a new supramolecular layer-by-layer (LbL) self-assembly method to achieve reversible and adjustable multiple gating features in nanofluidic diodes. Initially, a self-assembly precursor was modified into a single conical nanochannel, then host molecule-cucurbit[8]uril (CB[8]) and guest molecule, a naphthalene derivative, were self-assembled onto the precursor through an LbL method driven by host-enhanced π-π interaction, forming supramolecular monolayer or multilayers on the inner surface of the channel. These self-assemblies with different layer numbers possessed remarkable charge effects and steric effects, exhibiting a capability to regulate the surface charge density and polarity, the effective diameter, and the geometric asymmetry of the single nanochannel, realizing reversible gating of the single nanochannel among multiple rectification and ion-conduction states. As an example of self-assembly of supramolecular networks in nanoconfinements, this work provides a new approach for enhancing functionalities of artificial nanochannels by LbL supramolecular self-assemblies. Meanwhile, since the host molecule, CB[8], used in this work can interact with different kinds of biomolecules and stimuli-responsive chemical species, this work can be further extended to build a novel stable multiple-state research platform for a variety of uses such as sensing and controllable release.

Nanopores and nanochannels are ubiquitous, from biological systems to various artificial materials. Taking advantage of size confinement and tailoring the interior components, numerous functions can be achieved such as selectivity, gating, rectification, and so on, which result from diverse interactions between ion/molecule and nanopore/nanochannel. In this Perspective, on account of the summarized critical principles, namely size/shape, wettability, charge, recognition, and other interactions during ion/molecule transportation in nanopores and nanochannels, we introduce four main sections of applications: selective transportation in separation, controllable gating systems, energy conversion devices, and sensors. In addition, some typical challenges and possible future research endeavors in the related fields will also be discussed.

Engineered asymmetric membranes for intelligent molecular and ionic transport control at the nanoscale have gained significant attention and offer prospects for broad application in nanofluidics, energy conversion, and biosensors. Therefore, it is desirable to construct a high-performance heterogeneous membrane capable of coordinating highly selective and rectified ionic transport with a simple, versatile, engineered method to mimic the delicate functionality of biological channels. Here, we demonstrate an engineered asymmetric heterogeneous membrane by combining a porous block copolymer (BCP) membrane, polystyrene-b-poly(4-vinylpyridine) (PS48400-b-P4VP21300), with a track-etched asymmetric porous polyethylene terephthalate membrane. The introduction of chemical, geometrical, and electrostatic heterostructures provides our heterogeneous membrane with excellent anion selectivity and ultrahigh ionic rectification with a ratio of ca. 1075, which is considerably higher than that of existing ionic rectifying systems. This anion-selective heterogeneous membrane was further developed into an energy conversion device to harvest the energy stored in an electrochemical concentration gradient. The concentration polarization phenomenon that commonly exists in traditional reverse electrodialysis can be eliminated with an asymmetric bipolar structure, which considerably increases the output power density. This work presents an important paradigm for the use of versatile BCPs in nanofluidic systems and opens new and promising routes to various breakthroughs in the fields of chemistry, materials science, bioscience, and nanotechnology.

While antimicrobial peptides (AMPs) have been widely investigated as potential therapeutics, high-resolution structures obtained under biologically relevant conditions are lacking. Here, the high-resolution structures of the homologous 22-residue long AMPs piscidin 1 (p1) and piscidin 3 (p3) are determined in fluid-phase 3:1 phosphatidylcholine/phosphatidylglycerol (PC/PG) and 1:1 phosphatidylethanolamine/phosphatidylglycerol (PE/PG) bilayers to identify molecular features important for membrane destabilization in bacterial cell membrane mimics. Structural refinement of (1)H-(15)N dipolar couplings and (15)N chemical shifts measured by oriented sample solid-state NMR and all-atom molecular dynamics (MD) simulations provide structural and orientational information of high precision and accuracy about these interfacially bound α-helical peptides. The tilt of the helical axis, τ, is between 83° and 93° with respect to the bilayer normal for all systems and analysis methods. The average azimuthal rotation, ρ, is 235°, which results in burial of hydrophobic residues in the bilayer. The refined NMR and MD structures reveal a slight kink at G13 that delineates two helical segments characterized by a small difference in their τ angles (10°) and significant difference in their ρ angles (~25°). Remarkably, the kink, at the end of a G(X)4G motif highly conserved among members of the piscidin family, allows p1 and p3 to adopt ρ angles that maximize their hydrophobic moments. Two structural features differentiate the more potent p1 from p3: p1 has a larger ρ angle and less N-terminal fraying. The peptides have comparable depths of insertion in PC/PG, but p3 is 1.2 Å more deeply inserted than p1 in PE/PG. In contrast to the ideal α-helical structures typically assumed in mechanistic models of AMPs, p1 and p3 adopt disrupted α-helical backbones that correct for differences in the amphipathicity of their N- and C-ends, and their centers of mass lie ~1.2-3.6 Å below the plane defined by the C2 atoms of the lipid acyl chains.

Here we report that the rod-like tobacco mosaic virus (TMV), having a negatively charged surface, can be assembled into three-dimensional micrometer-sized bundle-like superstructures via multiple electrostatic interactions with a positively charged molecular "glue", namely, a tetraphenylethylene (TPE)-based discrete organoplatinum(II) metallacycle (TPE-Pt-MC). Due to the nanoconfinement effect in the resultant TMV/TPE-Pt-MC complexes and the aggregation-induced emission (AIE) activity of the TPE units, these hierarchical architectures result in a dramatic fluorescence enhancement that not only provides evidence for the formation of novel metal-organic biohybrid materials but also represents an alternative to turn-on fluorescence. Moreover, the dissociation of these final constructs and subsequent release of individual virus have been achieved by disrupting the TPE-Pt-MC core using tetrabutylammonium bromide (TBAB). This strategy is also compatible with other protein-based nanoparticles such as bacteriophage M13 and ferritin, proving the generality of this approach. Hence, this research will open new routes for the fabrication of functional biohybrid materials involving metal-organic complexes and anisotropically shaped bionanoparticles.

The three-dimensional structure of the 81-residue mercury transporter MerF determined in liquid crystalline phospholipid bilayers under physiological conditions by Rotationally Aligned (RA) solid-state NMR has two long helices, which extend well beyond the bilayer, with a well-defined interhelical loop. Truncation of the N-terminal 12 residues, which are mobile and unstructured when the protein is solubilized in micelles, results in a large structural rearrangement of the protein in bilayers. In the full-length protein, the N-terminal helix is aligned nearly parallel to the membrane normal and forms an extension of the first transmembrane helix. By contrast, this helix adopts a perpendicular orientation in the truncated protein. The close spatial proximity of the two Cys-containing metal binding sites in the three-dimensional structure of full-length MerF provides insights into possible transport mechanisms. These results demonstrate that major changes in protein structure can result from differences in amino acid sequence (e.g., full-length vs truncated proteins) as well as the use of a non-native membrane mimetic environment (e.g., micelles) vs liquid crystalline phospholipid bilayers. They provide further evidence of the importance of studying unmodified membrane proteins in near-native bilayer environments in order to obtain accurate structures that can be related to their functions.

Superwettability is a special case of the wetting phenomenon among liquids, gases, and solids. The superhydrophobic/superhydrophilic effect discovered initially has undergone a century of development based on materials science and biomimetics. With the rapid development of research on anti-wetting materials, superoleophobic/superoleophilic surfaces have been fabricated to repel organic liquids besides water. Further studies of underwater superoleophobic/superoleophilic/superaerophobic/superaerophilic materials provide an alternative way to fabricate anti-wetting surfaces rather than lowering the surface energy. Owing to a series of efforts on the studying of extreme wettabilities, a mature superwettability system gradually evolved and has since become a vibrant area of active research, covering topics of superhydrophobicity/superhydrophilicity, superoleophobicity/superoleophilicity in gas or under liquid, superaerophobicity/superaerophilicity under liquid, and combinations of these states. The kinetic study of the superwettability system includes statics and dynamics, while the studied material structures range from traditional two-dimensional materials to three-dimensional, one-dimensional, and zero-dimensional materials. Furthermore, the wetting liquids range from water to oil, aqueous solutions, and ionic liquids, as well as liquid crystals and other types of liquids. The wetting conditions extend over a wide range of temperatures, pressures, and other external fields. With the development of this series of research, many new theories and functional interfacial materials have been fabricated, including self-cleaning textiles, oil/water separation systems, and water collection systems, and some of these have already been applied in industry. Moreover, the study of superwettability has also introduced many new phenomena and principles to the field of interfacial chemistry that display its vast potential in both materials and chemistry. The present Perspective aims to summarize the most recent research on these materials and their interfacial chemistry. An overview of novel materials in superwettability systems and interfacial materials is presented. Specifically, the evolution of superwettable materials will be introduced, and the fundamental rules for building these superwetting materials will be discussed, followed by a summary of recent progress in the application of superwettable materials to alter the behaviors of chemical reactants and products. Specific emphasis is placed on recent strategies that exploit superwettable materials to influence the performance of traditional chemical reactions and their unique contributions to chemistry, including the effective collection of reaction products, unique growth models of precipitates, and a simple strategy for the alignment/assembly of nanoscale building blocks. Finally, a short perspective is provided on the potential for future developments in the field.

Design and synthesis of super-nanostructures is one of the key and prominent topics in nanotechnology. Here we propose a novel methodology for synthesizing complex hierarchical superstructures using sacrificial templates composed of ordered two-dimensional (2D) nanostructures through lattice-directed topotactic transformations. The fabricated superstructures are nested 2D orthogonal Bi(2)S(3) networks composed of nanorods. Further investigation indicates that the lattice matching between the product and sacrificial template is the dominant mechanism for the formation of the superstructures, which agrees well with the simulation results based on an anisotropic nucleation and growth analysis. Our approach may provide a promising way toward a lattice-directed nonlithographic nanofabrication technique for making functional porous nanoarchitectures and electronic devices.

Potassium is especially crucial in modulating the activity of muscles and nerves whose cells have specialized ion channels for transporting potassium. Normal body function extremely depends on the regulation of potassium concentrations inside the ion channels within a certain range. For life science, undoubtedly, it is significant and challenging to study and imitate these processes happening in living organisms with a convenient artificial system. Here we report a novel biomimetic nanochannel system which has an ion concentration effect that provides a nonlinear response to potassium ion at the concentration ranging from 0 to 1500 microM. This new phenomenon is caused by the G-quadruplex DNA conformational change with a positive correlation with ion concentration. In this work, G-quadruplex DNA was immobilized onto a synthetic nanopore, which undergoes a potassium-responsive conformational change and then induces the change in the effective pore size. The responsive ability of this system can be regulated by the stability of G-quadruplex structure through adjusting potassium concentration. The situation of the grafting G-quadruplex DNA on a single nanopore can closely imitate the in vivo condition because the G-rich telomere overhang is attached to the chromosome. Therefore, this artificial system could promote a potential to conveniently study biomolecule conformational change in confined space by the current measurement, which is significantly different from the nanopore sequencing. Moreover, such a system may also potentially spark further experimental and theoretical efforts to simulate the process of ion transport in living organisms and can be further generalized to other more complicated functional molecules for the exploitation of novel bioinspired intelligent nanopore machines.

Bioinspired artificial functional nanochannels for intelligent molecular and ionic transport control at the nanoscale have wide potential applications in nanofluidics, energy conversion, and biosensors. Although various smart passive ion transport properties of ion channels have been artificially realized, it is still hugely challenging to achieve high level intelligent ion transport features in biological ion pumps. Here we show a unique bioinspired single ion pump based on a cooperative pH response double-gate nanochannel, whose gates could be opened and closed alternately/simultaneously under symmetric/asymmetric pH environments. With the stimulation of the double-gate nanochannel by continuous switching of the symmetric/asymmetric pH stimuli, the bioinspired system systematically realized three key ionic transport features of biological ion pumps, including an alternating gates ion pumping process under symmetric pH stimuli, transformation of the ion pump into an ion channel under asymmetric pH stimuli, and a fail-safe ion pumping feature under both symmetric and asymmetric pH stimuli. The ion pumping processes could well be reproduced under a concentration gradient. With the advantages of the extraordinary ionic transport functions of biological ion pumps, the bioinspired ion pump should find widespread applicability in active transportation-controlling smart nanofluidic devices, efficient energy conversions, and seawater desalinization, and open the way to design and develop novel bioinspired intelligent artificial nanochannel materials.

We have developed a strategy for preparing antibody nanoarrays by DNA templating. In the resulting tetragonal antibody arrays, each spot is a similarly orientated, individual antibody molecule (IgG). The separation between two adjacent IgG molecules is only approximately 20 nm.

A pair of DNA nanocircles has been constructed to model gears. The nanogears can move against each other continuously. Each gear consists of a DNA duplex circle and three single-stranded teeth. The teeth on the two gears are brought together by linker strands, which are complementary to the gear teeth. The teeth are separated from each other by removal of the linker strands with a strand displacement mechanism.

This paper reports a novel DNA six-point-star motif assembled from only three different DNA single-strands. This motif readily assembles into hexagonal two-dimensional arrays with high connectivity. Such a high connectivity could potentially improve the array stability.

A host-guest compound containing mononuclear univalent Zn+ ions has been prepared through vapor reaction of metallic zinc with protons in the cages of SAPO-CHA, a silicoaluminophosphate molecular sieve. Unlike in fused ZnCl2 salt, the formed Zn+ species are associated with the molecular sieve walls, and this prevents the cations from getting paired to form diamagnetic (Zn-Zn)2+. Electron spin resonance spectroscopy reveals the paramagnetic nature of the Zn+ species which display anisotropic g factors, and the two crystallographically independent Zn+ sites are distinguishable from the ESR signals. The magnetic moments of the univalent zinc in SAPO-CHA interact antiferromagnetically at low temperatures with a Néel point of about 4 K as observed from the temperature dependence plot of the magnetic susceptibility of the host-guest compound.