Precise Self-Assembly of Nanoparticles into Ordered Nanoarchitectures Directed by Tobacco Mosaic Virus Coat Protein

Assembly and Functionality of 2D Protein Arrays

Among the unique classes of 2D nanomaterials, 2D protein arrays garner increasing attention due to their remarkable structural stability, exceptional physiochemical properties, and tunable electronic and mechanical attributes. The interest in mimicking and surpassing the precise architecture and advanced functionality of natural protein systems drives the field of 2D protein assembly toward the development of sophisticated functional materials. Recent advancements deepen the understanding of the fundamental principles governing 2D protein self-assembly, accelerating the creation of novel functional biomaterials. These developments encompass biological, chemical, and templated strategies, facilitating the self-organization of proteins into highly ordered and intricate 2D patterns. Consequently, these 2D protein arrays create new opportunities for integrating diverse components, from small molecules to nanoparticles, thereby enhancing the performance and versatility of materials in various applications. This review comprehensively assesses the current state of 2D protein nanotechnology, highlighting the latest methodologies for directing protein assembly into precise 2D architectures. The transformative potential of 2D protein assemblies in designing next-generation biomaterials, particularly in areas such as biomedicine, catalysis, photosystems, and membrane filtration is also emphasized.

Non-Covalent Self-Assembly Behaviors Based on Racemic Binaphthol Scaffolds

Understanding the fundamental mechanisms involved in the construction and organization of multi-scale structures is crucial for the design and manufacture of complex functional systems with long-range molecular arrangements. In this paper, a series of compounds have been synthesized using racemic binaphthols as the skeleton and a Suzuki coupling reaction for derivatization at the 6,6' positions, which resulted in various structures bearing different functional groups. Control over the self-assembly of these racemic binaphthol derivatives was successfully achieved by adjusting the types and positions of the substituents in the parent binaphthol compound, which revealed the key factors influencing the types of the non-covalent interactions and the self-assembly process. For example, the single-crystal structures of the resulting compounds indicated that assembly structures such as single helix and double helix based on non-traditional hydrogen bond motifs could be obtained, and fascinating non-covalent self-assembly structures such as molecular ladders and catenane discovered.

Fast synthesis of DNA origami single crystals at room temperature

Structural DNA nanotechnology makes the programmable design and assembly of DNA building blocks into user-defined microstructures feasible. However, the formation and further growth of these microstructures requires slow heat treatment in precise instruments, as otherwise amorphous aggregates result. Here, we used an organic solute, urea, as the catalyst for the crystallization of DNA origami building blocks to achieve the fast synthesis of DNA origami single crystals with a cubic Wulff shape at room temperature. The ordered assemblies can be formed within 4 hours at room temperature, which further grew into cubic microcrystals with an average size of about 5 micrometers within 2 days. Furthermore, the phase diagram provides an inverse logic that allows users to proactively customize the melting temperature (T m) of crystallization according to the target temperature conditions, rather than requiring de novo design of DNA sequences or painstakingly difficult trial-and-error attempts. On this basis, even under random fluctuating outdoor temperature conditions, DNA origami crystals can still grow and maintain high quality and high yield comparable to those of crystals synthesized in precise instruments, creating a basis for the development of adaptive self-assemblies and the industrialization of functional DNA microstructures.

Terminal Tryptophan-Directed Anisotropic Self-Assembly for Precise Protein Nanostructure Regulation

A common challenge in nanotechnology is synthesizing nanomaterials with well-defined structures. In particular, it remains a major unresolved challenge to precisely regulate the structure and function of protein nanomaterials, which are structurally diverse, highly ordered, and complex and offer an innovative means that enables a high performance in various nanodevices, which is rarely achievable with other nanomaterials. Here an innovative approach is proposed to fabricating multi-dimensional (0- to 3D) protein nanostructures with functional and structural specialties via molecular-level regulation. This approach is based on a stable, consistent, anisotropic self-assembly of Tobacco mosaic virus (TMV) coat protein-derived engineered building blocks where genetically added tryptophan residues are externally tailored. The unique structural characteristics of each nanostructure above are demonstrated in detail through various analyses (electron microscopy, atomic force microscopy, dynamic light scattering, and small-angle X-ray scattering) and further investigated through molecular dynamics simulations, indicating that this control, anisotropic, and molecular assembly-based approach to regulating protein nanostructures holds great potential for customizing a variety of nanomaterials with unique functions and structures.

Strategies and Applications for Supramolecular Protein Self-Assembly

Supramolecular chemistry achieves higher-order molecular self-assembly through non-covalent interactions. Utilizing supramolecular methods to explore the polymorphism of proteins, the building blocks of life, from a "bottom-up" perspective is essential for constructing diverse and functional biomaterials. In recent years, significant progress has been achieved in the design strategies and functional applications of supramolecular protein self-assembly, becoming a focal point for researchers. This paper reviews classical supramolecular strategies driving protein self-assembly, including electrostatic interactions, metal coordination, hydrogen bonding, hydrophobic interactions, host-guest interactions, and other mechanisms. We discuss how these supramolecular interactions regulate protein assembly processes and highlight protein supramolecular assemblies' unique structural and functional advantages in constructing artificial photosynthetic systems, protein hydrogels, bio-delivery systems, and other functional materials. The enormous potential and significance of supramolecular protein materials are elucidated. Finally, the challenges in preparing and applying protein supramolecular assemblies are summarized, and future development directions are projected.

Surface-enhanced Raman scattering based on noble metal nanoassemblies for detecting harmful substances in food

Residues of harmful substances in food can severely damage human health. The content of these substances in food is generally low, making detection difficult. Surface-enhanced Raman scattering (SERS), based on noble metal nanomaterials, mainly gold (Au) and silver (Ag), has exhibited excellent capabilities for trace detection of various substances. Noble metal nanoassemblies, in particular, have extraordinary flexibility and tunable optical properties, which cannot be offered by single nanoparticles (NPs). These nanoassemblies, with their various morphologies synthesized using NPs through artificially induced self-assembly or template-driven preparation, can significantly enhance the local electric field and create "hot spots" due to the gaps between adjacent NPs. Consequently, the SERS properties of NPs become more prominent, leading to improved performance in the trace detection of various substances and detection limits that are considerably lower than the current relevant standards. Noble metal nanoassemblies show promising potential in ensuring food safety. This review discusses the synthesis methods and SERS properties of noble metal nanoassemblies and then concentrates on their application in detecting biotoxins, drug residues, illegal additives, and heavy metals. The study provides valuable references for further research into the application of nanoassemblies in food safety detection.

Advancements in Functional Nanomaterials Inspired by Viral Particles

Virus-like particles (VLPs) are nanostructures composed of one or more structural proteins, exhibiting stable and symmetrical structures. Their precise compositions and dimensions provide versatile opportunities for modifications, enhancing their functionality. Consequently, VLP-based nanomaterials have gained widespread adoption across diverse domains. This review focuses on three key aspects: the mechanisms of viral capsid protein self-assembly into VLPs, design methods for constructing multifunctional VLPs, and strategies for synthesizing multidimensional nanomaterials using VLPs. It provides a comprehensive overview of the advancements in virus-inspired functional nanomaterials, encompassing VLP assembly, functionalization, and the synthesis of multidimensional nanomaterials. Additionally, this review explores future directions, opportunities, and challenges in the field of VLP-based nanomaterials, aiming to shed light on potential advancements and prospects in this exciting area of research.

Biosynthesis of metal nanoparticles: Bioreduction and biomineralization

The biosynthesis of metal nanoparticles by plants, bacteria, and cells has been receiving considerable attention in recent years. The traditional synthesis of metal nanoparticles always needed high temperatures, high pressure, and toxic agents. However, the biosynthesis process (including bioreduction and biomineralization) is simpler, safe, economical, and green. The process of biosynthesis can insulate toxic agents, streamline flux, increase the transition efficiency of interactants, and improve the product yield. The biosynthesized metal nanoparticles share similar characteristics with traditional ones, serving as photosensors to achieve light-to-heat/energy transduction, or a drug delivery system. The biosynthetic metal nanoparticles thus could be widely applied in the medical field for disease diagnosis and treatment. It contributed a novel modality for the facile and green synthesis of metal nanoparticles. Increasing studies have been exploring the mechanism for the biosynthesis of metal nanoparticles, devoted to a controllable biosynthesis process. Combined with our previous studies on the biosynthesis of gold nanoparticles with green tea, tumor cells, and cell components, we reviewed the green methods of bioreduction and biomineralization of metal nanoparticles including the internal mechanism, aimed to make a comprehensive introduction to the biosynthesis of metal nanoparticles and relevant biomedical applications, and inspired further research.

Hierarchical Materials from High Information Content Macromolecular Building Blocks: Construction, Dynamic Interventions, and Prediction

Hierarchical materials that exhibit order over multiple length scales are ubiquitous in nature. Because hierarchy gives rise to unique properties and functions, many have sought inspiration from nature when designing and fabricating hierarchical matter. More and more, however, nature's own high-information content building blocks, proteins, peptides, and peptidomimetics, are being coopted to build hierarchy because the information that determines structure, function, and interfacial interactions can be readily encoded in these versatile macromolecules. Here, we take stock of recent progress in the rational design and characterization of hierarchical materials produced from high-information content blocks with a focus on stimuli-responsive and "smart" architectures. We also review advances in the use of computational simulations and data-driven predictions to shed light on how the side chain chemistry and conformational flexibility of macromolecular blocks drive the emergence of order and the acquisition of hierarchy and also on how ionic, solvent, and surface effects influence the outcomes of assembly. Continued progress in the above areas will ultimately usher in an era where an understanding of designed interactions, surface effects, and solution conditions can be harnessed to achieve predictive materials synthesis across scale and drive emergent phenomena in the self-assembly and reconfiguration of high-information content building blocks.

Precise Assembly of Proteins and Carbohydrates for Next-Generation Biomaterials

The complexity and diversity of biomacromolecules make them a unique class of building blocks for generating precise assemblies. They are particularly available to a new generation of biomaterials integrated with living systems due to their intrinsic properties such as accurate recognition, self-organization, and adaptability. Therefore, many excellent approaches have been developed, leading to a variety of quite practical outcomes. Here, we review recent advances in the fabrication and application of artificially precise assemblies by employing proteins and carbohydrates as building blocks, followed by our perspectives on some of new challenges, goals, and opportunities for the future research directions in this field.

Plant Viral Coat Proteins as Biochemical Targets for Antiviral Compounds

Coat proteins (CPs) of RNA plant viruses play a pivotal role in virus particle assembly, vector transmission, host identification, RNA replication, and intracellular and intercellular movement. Numerous compounds targeting CPs have been designed, synthesized, and screened for their antiviral activities. This review is intended to fill a knowledge gap where a comprehensive summary is needed for antiviral agent discovery based on plant viral CPs. In this review, major achievements are summarized with emphasis on plant viral CPs as biochemical targets and action mechanisms of antiviral agents. This review hopefully provides new insights and references for the further development of new safe and effective antiviral pesticides.

Fabrication and Molecular Modeling of Navette-Shaped Fullerene Nanorods Using Tobacco Mosaic Virus as a Nanotemplate

To date, metallization studies have been performed with the nanometer-scale template, Tobacco Mosaic Virus (TMV). Here we show that fullerenes as well can be deposited on TMV coat protein in a controlled manner. Two methods were followed for the coating process. First, underivatized fullerene was dispersed in different solvents to bring the underivatized fullerene and wild-type TMV together. Improved depositions were obtained with the fullerene dicarboxylic derivative synthesized via the Bingel method. The form of the coating was analyzed by transmission electron microscopy. Our results demonstrate that the coating efficiency with the carboxy derivative was much better compared to the underivatized fullerene. The goal of coupling a carbon nanoparticle to a biological molecule, the viral coat of TMV, was achieved with the carboxy derivative of fullerene, resulting in the production of navette-shaped nanorods. The interactions between carboxyfullerenes and TMV were investigated through modeling with computational simulations and Gaussian-based density functional theory (DFT) calculations using the Gaussian09 program package. The theoretical calculations supported the experimental findings. This inexpensive and untroublesome method promises new fullerene hybrid nanomaterials in particular shapes and structures.

1D Colloidal chains: recent progress from formation to emergent properties and applications

Integrating nanoscale building blocks of low dimensionality (0D; i.e., spheres) into higher dimensional structures endows them and their corresponding materials with emergent properties non-existent or only weakly existent in the individual building blocks. Constructing 1D chains, 2D arrays and 3D superlattices using nanoparticles and colloids therefore continues to be one of the grand goals in colloid and nanomaterial science. Amongst these higher order structures, 1D colloidal chains are of particular interest, as they possess unique anisotropic properties. In recent years, the most relevant advances in 1D colloidal chain research have been made in novel synthetic methodologies and applications. In this review, we first address a comprehensive description of the research progress concerning various synthetic strategies developed to construct 1D colloidal chains. Following this, we highlight the amplified and emergent properties of the resulting materials, originating from the assembly of the individual building blocks and their collective behavior, and discuss relevant applications in advanced materials. In the discussion of synthetic strategies, properties, and applications, particular attention will be paid to overarching concepts, fresh trends, and potential areas of future research. We believe that this comprehensive review will be a driver to guide the interdisciplinary field of 1D colloidal chains, where nanomaterial synthesis, self-assembly, physical property studies, and material applications meet, to a higher level, and open up new research opportunities at the interface of classical disciplines.

Alcohol-perturbed self-assembly of the tobacco mosaic virus coat protein

The self-assembly of the tobacco mosaic virus coat protein is significantly altered in alcohol-water mixtures. Alcohol cosolvents stabilize the disk aggregate and prevent the formation of helical rods at low pH. A high alcohol content favours stacked disk assemblies and large rafts, while a low alcohol concentration favours individual disks and short stacks. These effects appear to be caused by the hydrophobicity of the alcohol additive, with isopropyl alcohol having the strongest effect and methanol the weakest. We discuss several effects that may contribute to preventing the protein-protein interactions between disks that are necessary to form helical rods.

"Self-Adaptive" Coassembly of Colloidal "Saturn-like" Host-Guest Complexes Enabled by Toroidal Micellar Rubber Bands

The creation of inclusion complexes with "Saturn-like" geometries has attracted increasing attention for supramolecular systems, but expansion of the concept to nanoscale colloidal systems remains a challenge. Here, we report a strategy to assemble toroidal polyisoprene-b-poly(2-vinylpyridine) (PI-b-P2VP) block copolymer micelles with a PI core and a P2VP corona and inorganic (e.g., silica) nanoparticles of variable shape and dimensions into "Saturn-like" constructs with high fidelity and yield. The precise nesting of the nanoparticles between the toroidal building units is realized by virtue of hydrogen bonding and self-adaptive expansion of the flexible toroidal units enabled by a flexible, low T_g PI core. Once the toroidal units are cross-linked, the self-adaptive feature is lost and coassembly yields instead out-of-cavity bound nanoparticles. "Saturn-like" assemblies can also be formed along silica nanosphere-decorated cylindrical micelles or, alternatively, at the hydroxyl-functionalized termini of cylindrical micelles to yield colloidal [3]rotaxanes.

Assembly of Bioactive Nanoparticles via Metal-Phenolic Complexation

The integration of bioactive materials (e.g., proteins and genes) into nanoparticles holds promise in fields ranging from catalysis to biomedicine. However, it is challenging to develop a simple and broadly applicable nanoparticle platform that can readily incorporate distinct biomacromolecules without affecting their intrinsic activity. Herein, a metal-phenolic assembly approach is presented whereby diverse functional nanoparticles can be readily assembled in water by combining various synthetic and natural building blocks, including poly(ethylene glycol), phenolic ligands, metal ions, and bioactive macromolecules. The assembly process is primarily mediated by metal-phenolic complexes through coordination and hydrophobic interactions, which yields uniform and spherical nanoparticles (mostly <200 nm), while preserving the function of the incorporated biomacromolecules (siRNA and five different proteins used). The functionality of the assembled nanoparticles is demonstrated through cancer cell apoptosis, RNA degradation, catalysis, and gene downregulation studies. Furthermore, the resulting nanoparticles can be used as building blocks for the secondary engineering of superstructures via templating and cross-linking with metal ions. The bioactivity and versatility of the platform can potentially be used for the streamlined and rational design of future bioactive materials.

Protein Assembly by Design

Proteins are nature's primary building blocks for the construction of sophisticated molecular machines and dynamic materials, ranging from protein complexes such as photosystem II and nitrogenase that drive biogeochemical cycles to cytoskeletal assemblies and muscle fibers for motion. Such natural systems have inspired extensive efforts in the rational design of artificial protein assemblies in the last two decades. As molecular building blocks, proteins are highly complex, in terms of both their three-dimensional structures and chemical compositions. To enable control over the self-assembly of such complex molecules, scientists have devised many creative strategies by combining tools and principles of experimental and computational biophysics, supramolecular chemistry, inorganic chemistry, materials science, and polymer chemistry, among others. Owing to these innovative strategies, what started as a purely structure-building exercise two decades ago has, in short order, led to artificial protein assemblies with unprecedented structures and functions and protein-based materials with unusual properties. Our goal in this review is to give an overview of this exciting and highly interdisciplinary area of research, first outlining the design strategies and tools that have been devised for controlling protein self-assembly, then describing the diverse structures of artificial protein assemblies, and finally highlighting the emergent properties and functions of these assemblies.

Tunable Assembly of Protein Enables Fabrication of Platinum Nanostructures with Different Catalytic Activity

Proteins are promising biofunctional units for the construction of nanomaterials (NMs) due to their abundant binding sites, intriguing self-assembly properties, and mild NM synthetic conditions. Tobacco mosaic virus coat protein (TMVCP) is a protein capable of self-assembly into distinct morphologies depending on the solution pH and ionic strength. Herein, we report the use of TMVCP as a building block to organize nanosized platinum into discrete nanorings and isolated nanoparticles by varying the solution pH to modulate the protein assembly state. Compared with a commercial Pt/C catalyst, the TMVCP-templated platinum materials exhibited significant promotion of the catalytic activity and stability toward methanol electrooxidation in both neutral and alkaline conditions. The enhanced catalytic performance is likely facilitated by the protein support. Additionally, Pt nanorings outperformed isolated nanoparticles, although they are both synthesized on TMVCP templates. This could be due to the higher mechanical stability of the protein disk structure and possible cooperative effects between adjacent nanoparticles in the ring with narrow interparticle spacing.

Virus-Based Supramolecular Structure and Materials: Concept and Prospects

Rodlike and spherelike viruses are various monodisperse nanoparticles that can display small molecules or polymers with unique distribution following chemical modifications. Because of the monodisperse property, aggregates in synthetic protein-polymer nanoparticles could be eliminated, thus improving the probability for application in protein-polymer drug. In addition, the monodisperse virus could direct the growth of metal materials or inorganic materials, finding applications in hydrogel, drug delivery, and optoelectronic and catalysis materials. Benefiting from the advantages, the virus or viruslike particles have been widely explored in the field of supramolecular chemistry. In this review, we describe the modification and application of virus and viruslike particles in surpramolecular structures and biomedical research.

Unconventional-Phase Crystalline Materials Constructed from Multiscale Building Blocks

Crystal phase, an intrinsic characteristic of crystalline materials, is one of the key parameters to determine their physicochemical properties. Recently, great progress has been made in the synthesis of nanomaterials with unconventional phases that are different from their thermodynamically stable bulk counterparts via various synthetic methods. A nanocrystalline material can also be viewed as an assembly of atoms with long-range order. When larger entities, such as nanoclusters, nanoparticles, and microparticles, are used as building blocks, supercrystalline materials with rich phases are obtained, some of which even have no analogues in the atomic and molecular crystals. The unconventional phases of nanocrystalline and supercrystalline materials endow them with distinctive properties as compared to their conventional counterparts. This Review highlights the state-of-the-art progress of nanocrystalline and supercrystalline materials with unconventional phases constructed from multiscale building blocks, including atoms, nanoclusters, spherical and anisotropic nanoparticles, and microparticles. Emerging strategies for engineering their crystal phases are introduced, with highlights on the governing parameters that are essential for the formation of unconventional phases. Phase-dependent properties and applications of nanocrystalline and supercrystalline materials are summarized. Finally, major challenges and opportunities in future research directions are proposed.

Engineering conductive protein films through nanoscale self-assembly and gold nanoparticles doping

Protein-based materials are usually considered as insulators, although conductivity has been recently shown in proteins. This fact opens the door to develop new biocompatible conductive materials. While there are emerging efforts in this area, there is an open challenge related to the limited conductivity of protein-based systems. This work shows a novel approach to tune the charge transport properties of protein-based materials by using electron-dense AuNPs. Two strategies are combined in a unique way to generate the conductive solid films: (1) the controlled self-assembly of a protein building block; (2) the templating of AuNPs by the engineered building block. This bottom-up approach allows controlling the structure of the films and the distribution of the AuNPs within, leading to enhanced conductivity. This work illustrates a promising strategy for the development of effective hybrid protein-based bioelectrical materials.

Controlled and Stable Patterning of Diverse Inorganic Nanocrystals on Crystalline Two-Dimensional Protein Arrays

Controlled patterning of nanoparticles on bioassemblies enables synthesis of complex materials for applications in optics, nanoelectronics, and sensing. Biomolecular self-assembly offers molecular control for engineering patterned nanomaterials, but current approaches have been limited in their ability to combine high nanoparticle coverage with generality that enables incorporation of multiple nanoparticle types. Here, we synthesize photonic materials on crystalline two-dimensional (2D) protein sheets using orthogonal bioconjugation reactions, organizing quantum dots (QDs), gold nanoparticles (AuNPs), and upconverting nanoparticles along the surface-layer (S-layer) protein SbsB from the extremophile Geobacillus stearothermophilus. We use electron and optical microscopy to show that isopeptide bond-forming SpyCatcher and SnoopCatcher systems enable the simultaneous and controlled conjugation of multiple types of nanoparticles (NPs) at high densities along the SbsB sheets. These NP conjugation reactions are orthogonal to each other and to Au-thiol bond formation, allowing tailorable nanoparticle combinations at sufficient labeling efficiencies to permit optical interactions between nanoparticles. Fluorescence lifetime imaging of SbsB sheets conjugated to QDs and AuNPs at distinct attachment sites shows spatially heterogeneous QD emission, with shorter radiative decays and brighter fluorescence arising from plasmonic enhancement at short interparticle distances. This specific, stable, and efficient conjugation of NPs to 2D protein sheets enables the exploration of interactions between pairs of nanoparticles at defined distances for the engineering of protein-based photonic nanomaterials.

The Emerging Trend of Bio-Engineering Approaches for Microbial Nanomaterial Synthesis and Its Applications

Micro-organisms colonized the world before the multi-cellular organisms evolved. With the advent of microscopy, their existence became evident to the mankind and also the vast processes they regulate, that are in direct interest of the human beings. One such process that intrigued the researchers is the ability to grow in presence of toxic metals. The process seemed to be simple with the metal ions being sequestrated into the inclusion bodies or cell surfaces enabling the conversion into nontoxic nanostructures. However, the discovery of genome sequencing techniques highlighted the genetic makeup of these microbes as a quintessential aspect of these phenomena. The findings of metal resistance genes (MRG) in these microbes showed a rather complex regulation of these processes. Since most of these MRGs are plasmid encoded they can be transferred horizontally. With the discovery of nanoparticles and their many applications from polymer chemistry to drug delivery, the demand for innovative techniques of nanoparticle synthesis increased dramatically. It is now established that microbial synthesis of nanoparticles provides numerous advantages over the existing chemical methods. However, it is the explicit use of biotechnology, molecular biology, metabolic engineering, synthetic biology, and genetic engineering tools that revolutionized the world of microbial nanotechnology. Detailed study of the micro and even nanolevel assembly of microbial life also intrigued biologists and engineers to generate molecular motors that mimic bacterial flagellar motor. In this review, we highlight the importance and tremendous hidden potential of bio-engineering tools in exploiting the area of microbial nanoparticle synthesis. We also highlight the application oriented specific modulations that can be done in the stages involved in the synthesis of these nanoparticles. Finally, the role of these nanoparticles in the natural ecosystem is also addressed.

Noncovalent Self-Assembly of Protein Crystals with Tunable Structures

Engineering noncovalent interactions for assembling nonspherical proteins into supramolecular architectures with tunable morphologies and dynamics is challenging due to the structural heterogeneity and complexity of protein surfaces. Herein, we employed an anisotropic building block l-rhamnulose-1-phosphate aldolase (RhuA) to control supramolecular polymorphism in highly ordered protein assemblies by introducing histidine residues. Histidine-based π-π stacking interactions enabled thermodynamically controlled self-organization of RhuA to form three-dimensional (3D) nanoribbons and crystals. Self-assembly of different 3D crystal phases was kinetically modulated by the strong metal ion-histidine chelation, and double-helical protein superstructures were formed by engineering increased histidine interactions at the RhuA binding surface. Their structural properties and dynamics were determined via fluorescence microscopy, transmission electron microscopy, atomic force microscopy, and small-angle X-ray scattering. This work is aimed at expanding the toolbox for the programming of tunable, highly ordered, protein superstructures and increasing the understanding of the mechanisms of protein interfacial interactions.

Hollow Tobacco Mosaic Virus Coat Protein Assisted Self-Assembly of One-Dimensional Nanoarchitectures

Herein, an efficient strategy to fabricate well-organized one-dimensional (1D) inorganic nanostructures is demonstrated by utilizing the hollow tobacco mosaic virus coat protein (TMVCP) as a restrictive template. Considering the advantages of the unique hollow structure and the dynamic self-assembly attribute of TMVCP, foreign nano-objects are successfully encapsulated and conveniently assembled into highly organized 1D chainlike structures in the cavity of the TMVCP multimer (TMV disk). Different kinds of functional nanoparticles, such as gold nanoparticles (AuNPs) and silver sulfide quantum dots (Ag₂S QDs), are used to demonstrate the successful construction of ordered 1D nanochains in high yields. Notably, binary nanochains of such different kinds of nanoparticles are also constructed through co-assembling the TMV disk-coated AuNPs and Ag₂S QDs. Further, the TMV-assisted AuNP nanochains are grown into the 1D nanowires through in situ Au deposition owing to the spatial confinement of the TMVCP cavity. Together, our findings indicate that the TMV-assisted self-assembly approach, resulting in higher yields and better controllability over the other reported studies based on directly mineralizing the metal architectures in the TMV nanorods, provides enormous potential toward the fabrication of highly complex hybrid-metal nanostructures.

DNA-Based Plasmonic Heterogeneous Nanostructures: Building, Optical Responses, and Bioapplications

The integration of multiple functional nanoparticles into a specific architecture allows the precise manipulation of light for coherent electron oscillations. Plasmonic metals-based heterogeneous nanostructures are fabricated by using DNA as templates. This comprehensive review provides an overview of the controllable synthesis and self-assembly of heterogeneous nanostructures, and analyzes the effects of structural parameters on the regulation of optical responses. The potential applications and challenges of heterogeneous nanostructures in the fields of biosensors and bioanalysis, in vivo monitoring, and phototheranostics are discussed.

Guanosine Assembly Enabled Gold Nanorods with Dual Thermo- and Photoswitchable Plasmonic Chiroptical Activity

Noble metal nanostructures with plasmonic circular dichroism (PCD) have attracted interest, and a modulation of PCD is of great importance for their potential applications. Herein, we propose a supramolecular strategy for achieving dual thermal and photoswitchable PCD. When guanosine (G), deoxyguanosine (dG), and boric acid modified achiral gold nanorods (GNRs) were coassembled into a hydrogel, hybrid nanofibers with PCD were produced. When the hydrogel was heated, the nanofiber was disassembled and the PCD disappeared. As the hydrogel was thermally reversible, a thermo-controlled PCD could be realized. The hybrid hydrogel also showed photoswitchable PCD. When the gel was irradiated with an IR laser, the PCD disappeared. It can be restored by being placed at room temperature. Moreover, the hybrid gel was selectively responsive to the circularly polarized light (CPL). For (G/dG)-GNR hybrid assemblies, the R-CPL irradiation showed photothermal efficiency higher than that of L-CPL, which made it useful for an IR-irradiation-controlled release of drug molecules.

Hierarchical Self-Assembly of Proteins Through Rationally Designed Supramolecular Interfaces

With the increasing advances in the basic understanding of pathogenesis mechanism and fabrication of advanced biological materials, protein nanomaterials are being developed for their potential bioengineering research and biomedical applications. Among different fabrication strategies, supramolecular self-assembly provides a versatile approach to construct hierarchical nanostructures from polyhedral cages, filaments, tubules, monolayer sheets to even cubic crystals through rationally designed supramolecular interfaces. In this mini review, we will briefly recall recent progress in reconstituting protein interfaces for hierarchical self-assembly and classify by the types of designed protein-protein interactions into receptor-ligand recognition, electrostatic interaction, metal coordination, and non-specific interaction networks. Moreover, some attempts on functionalization of protein superstructures for bioengineering and/or biomedical applications are also shortly discussed. We believe this mini review will outline the stream of hierarchical self-assembly of proteins through rationally designed supramolecular interfaces, which would open minds in visualizing protein-protein recognition and assembly in living cells and organisms, and even constructing multifarious functional bionanomaterials.

Precise Fabrication of De Novo Nanoparticle Lattices on Dynamic 2D Protein Crystalline Lattices

The science of protein self-assembly has experienced significant development, from discrete building blocks of self-assembled nanoarchitectures to advanced nanostructures with adaptive functionalities. Despite the prominent achievements in the field, the desire of designing de novo protein-nanoparticle (NP) complexes and constructing dynamic NP systems remains highly challenging. In previous works, l-rhamnulose-1-phosphate aldolase (^C98RhuA) tetramers were self-assembled into two-dimensional (2D) lattices via disulfide bond interactions. These interactions provided 2D lattices with high structural quality and a sophisticated assembly mode. In this study, we devised a rational design for RhuA building blocks to fabricate 2D functionalized protein lattices. More importantly, the lattices were used to direct the precise assembly of NPs into highly ordered and diverse nanoarchitectures. These structures can be employed as an excellent tool to adequately verify the self-assembly mode and structural quality of the designed RhuA crystals. The subsequent redesign of RhuA building blocks enabled us to predictably produce a novel protein lattice whose conformational dynamics can be controllably regulated. Thus, a dynamic system of AuNP lattices was achieved. Transmission electron microscopy and small-angle X-ray scattering indicated the presence of these diverse NP lattices. This contribution enables the fabrication of future NP structures in a more programmable manner with more expected properties for potential applications in nanoelectronics and other fields.

Soft-Matter Nanotubes: A Platform for Diverse Functions and Applications

Self-assembled organic nanotubes made of single or multiple molecular components can be classified into soft-matter nanotubes (SMNTs) by contrast with hard-matter nanotubes, such as carbon and other inorganic nanotubes. To date, diverse self-assembly processes and elaborate template procedures using rationally designed organic molecules have produced suitable tubular architectures with definite dimensions, structural complexity, and hierarchy for expected functions and applications. Herein, we comprehensively discuss every functions and possible applications of a wide range of SMNTs as bulk materials or single components. This Review highlights valuable contributions mainly in the past decade. Fifteen different families of SMNTs are discussed from the viewpoints of chemical, physical, biological, and medical applications, as well as action fields (e.g., interior, wall, exterior, whole structure, and ensemble of nanotubes). Chemical applications of the SMNTs are associated with encapsulating materials and sensors. SMNTs also behave, while sometimes undergoing morphological transformation, as a catalyst, template, liquid crystal, hydro-/organogel, superhydrophobic surface, and micron size engine. Physical functions pertain to ferro-/piezoelectricity and energy migration/storage, leading to the applications to electrodes or supercapacitors, and mechanical reinforcement. Biological functions involve artificial chaperone, transmembrane transport, nanochannels, and channel reactors. Finally, medical functions range over drug delivery, nonviral gene transfer vector, and virus trap.

Patterning Porous Networks through Self-Assembly of Programmed Biomacromolecules

Two-dimensional (2D) porous networks are of great interest for the fabrication of complex organized functional materials for potential applications in nanotechnologies and nanoelectronics. This review aims at providing an overview of bottom-up approaches towards the engineering of 2D porous networks by using biomacromolecules, with a particular focus on nucleic acids and proteins. The first part illustrates how the advancements in DNA nanotechnology allowed for the attainment of complex ordered porous two-dimensional DNA nanostructures, thanks to a biomimetic approach based on DNA molecules self-assembly through specific hydrogen-bond base pairing. The second part focuses the attention on how polypeptides and proteins structural properties could be used to engineer organized networks templating the formation of multifunctional materials. The structural organization of all examples is discussed as revealed by scanning probe microscopy or transmission electron microscopy imaging techniques.

Design of Hierarchical Beads for Efficient Label-Free Cell Capture

Defined hierarchical materials promise cell analysis and call for application-driven design in practical use. The further issue is to develop advanced materials and devices for efficient label-free cell capture with minimum instrumentation. Herein, the design of hierarchical beads is reported for efficient label-free cell capture. Silica nanoparticles (size of ≈15 nm) are coated onto silica spheres (size of ≈200 nm) to achieve nanoscale surface roughness, and then the rough silica spheres are combined with microbeads (≈150-1000 µm in diameter) to assemble hierarchical structures. These hierarchical beads are built via electrostatic interaction, covalent bonding, and nanoparticle adherence. Further, after functionalization by hyaluronic acid (HA), the hierarchical beads display desirable surface hydrophilicity, biocompatibility, and chemical/structural stability. Due to the controlled surface topology and chemistry, HA-functionalized hierarchical beads afford high cell capture efficiency up to 98.7% in a facile label-free manner. This work guides the development of label-free cell capture techniques and contributes to the construction of smart interfaces in bio-systems.