The clearance of nanoparticles (NPs) by mononuclear phagocyte system (MPS) from blood leads to high liver and spleen uptake and negatively impacts their tumor delivery efficiency. Here we systematically evaluated the in vitro and in vivo nanobio interactions of a two-dimensional (2D) model, gold (Au) nanorings, which were compared with Au nanospheres and Au nanoplates of similar size. Among different shapes, Au nanorings achieved the lowest MPS uptake and highest tumor accumulation. Among different sizes, 50 nm Au nanorings showed the highest tumor delivery efficiency. In addition, we demonstrated the potential use of Au naonrings in photoacoustic imaging and photothermal therapy. Thus, engineering the shape, surface area, and size of Au nanostructures is important in controlling NP–MPS interactions and improving the tumor uptake efficiency.Keywords: gold nanorings; macrophage uptake; nanobio interactions; photoacoustic imaging; photothermal therapy; tumor accumulation;

In this communication, we report a composite macroporous hydrogel sheet that can rapidly transform into multiple 3D shapes in response to near-infrared (NIR) light on demand. The transformation relies on the photo-thermal-induced asymmetric shrinking of the hydrogel material, which is further verified by finite element modeling.

Enzyme-based colorimetric assays have been widely used in research laboratories and clinical diagnosis for decades. Nevertheless, as constrained by the performance of enzymes, their detection sensitivity has not been substantially improved in recent years, which inhibits many critical applications such as early detection of cancers. In this work, we demonstrate an enzyme-free signal amplification technique, based on gold vesicles encapsulated with Pd–Ir nanoparticles as peroxidase mimics, for colorimetric assay of disease biomarkers with significantly enhanced sensitivity. This technique overcomes the intrinsic limitations of enzymes, thanks to the superior catalytic efficiency of peroxidase mimics and the efficient loading and release of these mimics. Using human prostate surface antigen as a model biomarker, we demonstrated that the enzyme-free assay could reach a limit of detection at the femtogram/mL level, which is over 103-fold lower than that of conventional enzyme-based assay when the same antibodies and similar procedure were used.Keywords: biomarker; detection; enzyme mimic; gold vesicle; iridium nanoparticles;

ConspectusCurrent interest in functional assemblies of inorganic nanoparticles (NPs) stems from their collective properties and diverse applications ranging from nanomedicines to optically active metamaterials. Coating the surface of NPs with polymers allows for tailoring of the interactions between NPs to assemble them into hybrid nanocomposites with targeted architectures. This class of building blocks is termed “hairy” inorganic NPs (HINPs). Regiospecific attachment of polymers has been used to achieve directional interactions for HINP assembly. However, to date anisotropic surface functionalization of NPs still remains a challenge.This Account provides a review of the recent progress in the self-assembly of isotropically functionalized HINPs in both the condensed state and aqueous solution as well as the applications of assembled structures in such areas as biomedical imaging and therapy. It aims to provide fundamental mechanistic insights into the correlation between structural characteristics and self-assembly behaviors of HINPs, with an emphasis on HINPs made from NPs grafted with linear block copolymer (BCP) brushes. The key to the anisotropic self-assembly of these HINPs is the generation of directional interactions between HINPs by designing the surrounding medium (e.g., polymer matrix) or engineering the surface chemistry of the HINPs. First, HINPs can self-assemble into a variety of 1D, 2D, or 3D nanostructures with a nonisotropic local arrangement of NPs in films. Although a template is not always required, a polymer matrix (BCPs or supramolecules) can be used to assist the assembly of HINPs to form hybrid architectures. The interactions between brushes of neighboring HINPs or between HINPs and the polymer matrix can be modulated by varying the grafting density and length of one or multiple types of polymers on the surface of the NPs. Second, the rational design of deformable brushes of BCP or mixed homopolymer tethers on HINPs enables the anisotropic assembly of HINPs (in analogy to molecular self-assembly) into complex functional structures in selective solvents. It is evidenced that the directional interactions between BCP-grafted NPs arise from the redistribution and conformation change of the long, flexible polymer tethers, while the lateral phase separation of brushes on NP surfaces is responsible for the assembly of HINPs carrying binary immiscible homopolymers. For HINPs decorated with amphiphilic BCP brushes, their self-assembly can produce a variety of hybrid structures, such as vesicles with a monolayer of densely packed NPs in the membranes and with controlled sizes, shapes (e.g., spherical, hemispherical, disklike), and morphologies (e.g., patchy, Janus-like). This strategy allows fine-tuning of the NP organization and collective properties of HINP assemblies, thus facilitating their application in effective cancer imaging, therapy, and drug delivery. We expect that the design and assembly of such HINPs with isotropic functionalization is likely to open up new avenues for the fabrication of new functional nanocomposites and devices because of its simplicity, low cost, and ease of scale-up.

This communication describes a robust wet-chemical synthetic strategy for the preparation of monodispersed circular and triangular gold nanorings. The localized surface plasmon resonance of the nanorings can be tuned by controlling the outer diameter and ridge thickness of the nanorings.

Metallic nanotubes represent a class of hollow nanostructures with unique catalytic properties. However, the wet-chemical synthesis of metallic nanotubes remains a substantial challenge, especially for those with dimensions below 50 nm. This communication describes a simultaneous alloying-etching strategy for the synthesis of Pt nanotubes with open ends by selective etching Au core from coaxial Au/Pt nanorods. This approach can be extended for the preparation of Pt nanorings when Saturn-like Au core/Pt shell nanoparticles are used. The diameter and wall thickness of both nanotubes and nanorings can be readily controlled in the range of 14–37 nm and 2–32 nm, respectively. We further demonstrated that the nanotubes with ultrathin side walls showed superior catalytic performance in oxygen reduction reaction.

This Communication describes a facile strategy for the fabrication of inorganic nanoparticle (NP)-loaded hybrid core–shell microgels. The formation of core–shell microgels constitutes a novel mechanism in which the ionic-crosslinking of charged polymers (e.g., alginate) drives the unidirectional migration of NPs towards the centre of droplets. This versatile strategy allows the encapsulation of inorganic NPs with different sizes, shapes and surface properties in the core of the microgels in a single step.

A combination of a microfluidic technique and laser-triggered reactions has been developed to fabricate functional gas-filled capsules (GFCs) on-demand with applications such as a pressure sensor. This method involves (i) the generation of monodispersed alginate microcapsules containing ammonium bicarbonate (AB) as gas resource and gold nanorods as a heating resource, in a microfluidic device; and (ii) the near-infrared light-triggered generation of gases from the AB-containing microcapsules and simultaneous encapsulation of the gases in an alginate shell to produce GFCs. Various functional substances such as dyes, quantum dots, and magnetic nanoparticles can be introduced into the shell of the GFCs to impart the system with multifunctionality. We further demonstrated the use of the GFCs as pressure sensors capable of sensing the variation in the pressure of environment.

We present the uniform and high-yield synthesis of a novel gold nanostructure of compass shape composed of a Au sphere at the central and two gradually thinning conical tips at the opposed poles. The Au compass shapes were synthesized through a seed-mediated growth approach employing a binary mixture of cetyltrimethylammonium bromide (CTAB) and sodium oleate (NaOL) as the structure-directing agents. Under the condition of single surfactant (CTAB), the spherical seeds tend to grow into larger spherical Au nanoparticles (NPs); while the spherical seeds favor the formation of Au compass shaped NPs using two mixed surfactants (CTAB/NaOL). The reaction kinetics clearly shows a growth mechanism of Au compass shaped NPs. Interestingly, due to their anisotropic structure, Au compass shaped NPs show two distinctive plasmonic resonances, similar to those from Au nanorods. Particularly, the longitudinal surface plasmon resonances of Au compass shaped NPs exhibit a broadly tunable range from 600 to 865 nm. In addition, the obtained Au compass shaped NPs can be self-assembled into a two-dimensional monolayer with closely packed and highly aligned NPs, which results in periodic arrays of overlapped Au tips, generating hot spots for high-performance surface-enhanced Raman scattering.Keywords: compass shape; gold nanoparticles; plasmon resonances; seed-mediated growth; self-assemble; surface-enhanced Raman scattering

The design and assembly of novel colloidal particles are of both academic and technological interest. We developed a wet-chemical route to synthesize monodisperse bent rigid silica rods by controlled perturbation of emulsion-templated growth. The bending angle of the rods can be tuned in a range of 0–50° by varying the strength of perturbation in the reaction temperature or pH in the course of rod growth. The length of each arm of the bent rods can be individually controlled by adjusting the reaction time. For the first time we demonstrated that the bent silica rods resemble banana-shaped liquid-crystal molecules and assemble into ordered structures with a typical smectic B2 phase. The bent silica rods could serve as a visualizable mesoscopic model for exploiting the phase behaviors of bent molecules which represent a typical class of liquid-crystal molecules.

There is a high demand on a simple, rapid, accurate, user-friendly, cost-effective, and nondestructive universal method for latent fingerprint (LFP) detection. Herein, we describe a combination imaging strategy for LFP visualization with high resolution using poly(styrene-alt-maleic anhydride)-b-polystyrene (PSMA-b-PS) functionalized gold nanoparticles (GNPs). This general approach integrates the merits of both colorimetric imaging and photoacoustic imaging. In comparison with the previous methods, our strategy is single-step and does not require the signal amplification by silver staining. The PSMA-b-PS functionalized GNPs have good stability, tunable color, and high affinity for universal secretions (proteins/polypeptides/amino acids), which makes our approach general and flexible for visualizing LFPs on different substrates (presumably with different colors) and from different people. Moreover, the unique optical property of GNPs enables the photoacoustic imaging of GNPs-deposited LFPs with high resolution. This allows observation of level 3 hyperfine features of LFPs such as the pores and ridge contours by photoacoustic imaging. This technique can potentially be used to identify chemicals within LFP residues. We believe that this dual-modality imaging of LFPs will find widespread use in forensic investigations and medical diagnostics.Keywords: block copolymer; colorimetric imaging; gold nanoparticles; latent fingerprints; photoacoustic imaging;

•Concurrent self-assembly produces discrete architectures with increasing complexity.•Challenges remain at this frontier of concurrent self-assembly.•Multiple amphiphiles interact competitively or cooperatively during self-assembly.•The integration of multiple components leads to materials with new properties.The design of nanostructures with increasing complexity and new functionality has garnered significant interest in recent years because of the potential applications ranging from biomedicine, tissue engineering to energy and optoelectronics. Concurrent self-assembly of multiple molecular and/or colloidal amphiphiles has emerged as an important strategy for constructing novel nanomaterials with desired architectures and properties. This review article provides an overview of recent advances in the design, synthesis and assembly behaviors of two or more amphiphiles with competitive or cooperative interactions. We highlight recent contributions on developing strategies of assembling multiple amphiphiles of lipids (or surfactants), block copolymers, and/or inorganic nanoparticles. We briefly outline our perspectives on concurrent assembly, and discuss challenges facing the field from the aspects of theories, experiments, and applications.This review article highlights recent advances in the concurrent self-assembly in which multiple building blocks are involved and coordinated to form nanostructures that are otherwise not easy to achieve by assembly of single components.

Although an analogy has been drawn between them, organic molecular amphiphiles (MAMs) and inorganic nanoparticle (NP) amphiphiles (NPAMs) are significantly different in dimension, geometry, and composition as well as their assembly behavior. Their concurrent assembly can synergetically combine the inherent properties of both building blocks, thus leading to new hybrid materials with increasing complexity and functionality. Here we present a new strategy to fabricate hybrid vesicles with well-defined shape, morphology, and surface pattern by coassembling MAMs of block copolymers (BCPs) and NPAMs comprising inorganic NPs tethered with amphiphilic BCPs. The assembly of binary mixtures generated unique hybrid Janus-like vesicles with different shapes, patchy vesicles, and heterogeneous vesicles. Our experimental and computational studies indicate that the different nanostructures arise from the delicate interplay between the dimension mismatch of the two types of amphiphiles, the entanglement of polymer chains, and the mobility of NPAMs. In addition, the entropic attraction between NPAMs plays a dominant role in controlling the lateral phase separation of the two types of amphiphiles in the membranes. The ability to utilize multiple distinct amphiphiles to construct discrete assemblies represents a promising step in the self-assembly of structurally complex functional materials.

Nature offers a plethora of astonishing examples of shapes and functions from the aspects of both simplicity and complexity. The creation of synthetic systems that can morph in a controlled manner as seen in nature is of paramount importance in many fields of fundamental and applied sciences. The tremendous interest in self-shaping materials stems from a wide range of applications for these materials, ranging from biomedical devices to aircraft design. This review article highlights recent advances in understanding and designing thin, sheet-like soft materials that can transform into complex three-dimensional structures in a controlled manner by modulating the internal stresses. We review the general principles underlying shape transformation phenomena in natural and synthetic systems, and the significant achievements in fabricating self-shaping of soft materials via representative examples. We conclude with a discussion on the challenges facing the field, and future directions from the perspective of theoretical and experimental methodology and interdisciplinary applications.

Recently, platinum (Pt) nanoparticles (NPs) have received increasing attention in the field of catalysis and medicine due to their excellent catalytic activity. To rationally design Pt NPs for these applications, it is crucial to understand the mechanisms underlying their catalytic and biological activities. This article describes a systematic study on the Pt NP-catalyzed decomposition of hydrogen peroxide (H2O2) and scavenging of superoxide (O2˙−) and singlet oxygen (1O2) over a physiologically relevant pH range of 1.12–10.96. We demonstrated that the catalytic activities of Pt NPs can be modulated by the pH value of the environment. Our results suggest that Pt NPs possess peroxidase-like activity of decomposing H2O2 into ˙OH under acidic conditions, but catalase-like activity of producing H2O and O2 under neutral and alkaline conditions. In addition, Pt NPs exhibit significant superoxide dismutase-like activity of scavenging O2˙− under neutral conditions, but not under acidic conditions. The 1O2 scavenging ability of Pt NPs increases with the increase in the pH of the environment. The study will provide useful guidance for designing Pt NPs with desired catalytic and biological properties.

This communication describes a novel strategy to achieve programmable shape transformation of hybrid hydrogel sheets by modulating both the in-plane and out-of-plane mismatches in mechanical properties. Both our experimental and computational results demonstrate that the shape transformation of hybrid hydrogel sheets shows rich features (e.g., rolling direction, axis, chirality, etc.) and versatile tunability (e.g., via various external stimuli, material properties, pattern geometry, etc.). This work can provide guidance for designing soft materials that are able to undergo more precise and complex shape transformation.

Individual inorganic nanoparticles (NPs) have been widely used in the fields of drug delivery, cancer imaging and therapy. There are still many hurdles that limit the performance of individual NPs for these applications. The utilization of highly ordered NP ensembles opens a door to resolve these problems, as a result of their new or advanced collective properties. The assembled NPs show several advantages over individual NP-based systems, such as improved cell internalization and tumor targeting, enhanced multimodality imaging capability, superior combination therapy arising from synergistic effects, possible complete clearance from the whole body by degradation of assemblies into original small NP building blocks, and so on. In this review, we discuss the potential of utilizing assembled NP ensembles for cancer imaging and treatment by taking plasmonic vesicular assemblies of Au NPs as an example. We first summarize the recent developments in the self-assembly of plasmonic vesicular structures of NPs from amphiphilic polymer-tethered NP building blocks. We further review the utilization of plasmonic vesicles of NPs for cancer imaging (e.g. multi-photon induced luminescence, photothermal, and photoacoustic imaging), and cancer therapy (e.g., photothermal therapy, and chemotherapy). Finally, we outline current challenges and our perspectives along this line.

Soft materials undergoing shape transformations in response to changes in ambient environment have potential applications in tissue engineering, robotics and biosensing. Generally, stimulus-responsive materials acquire two stable shapes corresponding to the “on” and “off” states of the external trigger. Here, we report a simple, yet versatile approach to induce multiple shape transformations of a planar hydrogel sheet, each triggered by a particular, well-defined external stimulus. The approach is based on the integration of small-scale multiple polymer components with distinct compositions in the composite gel sheet. In response to different stimuli, the structural components undergo differential swelling or shrinkage, which creates internal stresses within the composite hydrogel sheet and transforms its shape in a specific manner.

Asymmetric particles (APs) with broken centrosymmetry are of great interest, due to the asymmetric surface properties and diverse functionalities. In particular, organic/metal(oxide) APs naturally combine the significantly different and complementary properties of organic and inorganic species, leading to their unique applications in various fields. In this review article, we highlighted recent advances in the synthesis and applications of organic/metal(oxide) APs. This type of APs is grounded on chemical or physical interactions between metal(oxide) NPs and organic small molecular or polymeric ligands. The synthetic methodologies were summarized in three categories, including the selective surface modifications, phase separation of mixed ligands on the surface of metal(oxide) NPs, and direct synthesis of APs. We further discussed the unique applications of organic/metal(oxide) APs in self-assembly, sensors, catalysis, and biomedicine, as a result of the distinctions between asymmetrically distributed organic and inorganic components. Finally, challenges and future directions are discussed in an outlook section.

Hydrodynamic flow in a microfluidic (MF) device offers a high-throughput platform for the continuous and controllable self-assembly of amphiphiles. However, the role of hydrodynamics on the assembly of colloidal amphiphiles (CAMs) is still not well understood. This Article reports a systematic study of the assembly of CAMs, which consist of Au nanoparticles (AuNPs) grafted with amphiphilic block copolymers, into vesicles with a monolayer of CAMs in the membranes using laminar flows in MF flow-focusing devices. Our experimental and simulation studies indicate that the transverse diffusion of solvents and colloids across the boundary of neighboring lamellar flows plays a critical role in the assembly of CAMs into vesicles. The dimension of the vesicles can be controlled in the range of 100–600 nm by tuning the hydrodynamic conditions of the flows. In addition, the diffusion coefficient of CAMs was also critical for their assembly. Under the same flow conditions, larger CAMs generated larger assemblies as a result of the reduced diffusion rate of large amphiphiles. This work could provide fundamental guidance for the preparation of nanoparticle vesicles with applications in bioimaging, drug delivery, and nano- and microreactors.Keywords: amphiphilic nanoparticles; colloidal amphiphiles; hydrodynamic flow; microfluidics; self-assembly; vesicles;

This communication reports the amphiphilic block copolymer driven self-assembly of Au nanoflowers into nanoparticle vesicles and the near-infrared light triggered release of hydrophilic molecules encapsulated in vesicles.

This communication describes a facile method for the synthesis of conical-shaped Au nanoparticles with a hollow cavity by combining interfacial reaction and ultrasonic cavitation. The Au nanocones showed an enhancement factor of 7.7 × 108 in surface enhanced Raman scattering (SERS) detection.

A facile and versatile strategy was developed for the preparation of self-healing hydrogels containing double networks of both physically and chemically cross-linked polymers. The autonomous self-healing of the hydrogel was achieved through the dynamic bonding of physical cross-linking and the migration of ferric ions.

The formation of well-defined polymer/inorganic nanoparticles (NPs) hybrid micelles with high loading of the NPs is critical to the development of nanomaterials with desired optical, electric, magnetic, and mechanical properties. Herein, we introduce a simple strategy to encapsulate monodisperse polystyrene (PS)-grafted Au NPs into the PS core of PS-b-poly(4-vinylpyridine) (PS-b-PVP) micelles through block copolymer (BCP)-based supramolecular assembly. We demonstrate that selective incorporation of gold NPs into the PS cores during the assembly process can induce the formation of well-ordered hybrid micelles with spherical, cylindrical, or nanosheet morphologies. The number of NPs in each micelle can be effectively increased by simply increasing the content of NPs and adjusting the ratio of 3-n-pentadecylphenol (PDP) to the P4VP units accordingly. The balance between the NP loading (increasing the volume fraction of PS domain) and the PDP addition (increasing the volume fraction of PVP(PDP) domain) maintains the same micellar morphology while achieving high NP loading. Moreover, strong enthalphic attraction of H-bonding between PDP and P4VP can increase the effective interaction parameter of the system to maintain the strong segregation, leading to the formation of ordered structures. The mass density of NPs in the hybrid micelles was further enhanced after removal of the added PDP from the supramolecules. No macrophase separation or order–order morphological transition was observed even when the volume fraction of PS-grafted NPs (φNP-M) in the hybrid micelles reached 84.1 vol % (or 68 wt % on the ligand free NPs basis). Furthermore, we show that ordered clusters of NPs were generated within the spherical micelles when the φNP-M reached 72.5 vol %. This directed supramolecular assembly provides an easy means to tailor the interactions between BCPs and NPs, thus generating ordered structures which can only be achieved when the loading of NPs is high enough. This approach is versatile and applicable to different types of NPs and different micellar aggregates and supramolecular pairs. It offers a new route for preparing hybrids with applications in the fields of molecular electronic devices, high-density data storage, nanomedicine, and biosensors.

This paper describes an effective approach to order gold nanorods (NRs) within cylindrically confined microdomains of block copolymer- (BCP-) based supramolecular assemblies. Individual BCP micelles encapsulated with well-ordered NRs can be obtained by disassembling the supramolecular structures. The mismatch of binary polymer brushes with different lengths on the surface of the NRs was used to effectively improve the dispersion of the NRs within polymer matrix, due to enhanced wetting of the brushes by surrounding mismatch polymers. This enables us to quantitatively explore the location and orientation of the NRs within confined geometries. By varying the content of NRs, the aspect ratio of the NRs, or the diameter of the cylindrical BCP micelles, the orientation of the NRs within micelles can be tuned to form one-dimensional nanostrings with end-to-end organization of NRs along the micelles or with side-by-side twisted arrangement of NRs perpendicular to the micelles. UV–vis spectroscopy measurements and finite-difference time-domain (FDTD) calculations confirm that our approach provides a simple yet versatile route to tune the optical properties of the hybrid micelles by controlling the ordering of the NRs. This work provides guidelines for dispersing other functional anisotropic NPs, and lays groundwork for the fabrication of optical and electronic devices.

A multifunctional theranostic platform based on photosensitizer-loaded plasmonic vesicular assemblies of gold nanoparticles (GNPs) is developed for effective cancer imaging and treatment. The gold vesicles (GVs) composed of a monolayer of assembled GNPs show strong absorbance in the near-infrared (NIR) range of 650–800 nm, as a result of the plasmonic coupling effect between neighboring GNPs in the vesicular membranes. The strong NIR absorption and the capability of encapsulating photosensitizer Ce6 in GVs enable trimodality NIR fluorescence/thermal/photoacoustic imaging-guided synergistic photothermal/photodynamic therapy (PTT/PDT) with improved efficacy. The Ce6-loaded GVs (GV-Ce6) have the following characteristics: (i) high Ce6 loading efficiency (up to ∼18.4 wt %; (ii) enhanced cellular uptake efficiency of Ce6; (iii) simultaneous trimodality NIR fluorescence/thermal/photoacoustic imaging; (iv) synergistic PTT/PDT treatment with improved efficacy using single wavelength continuous wave laser irradiation.Keywords: gold vesicles; photoacoustic imaging; photodynamic therapy; photothermal therapy; plasmonic coupling effect; synergistic therapy

Asymmetric multicomponent nanoparticles (AMNPs) offer new opportunities for new-generation materials with improved or new synergetic properties not found in their individual components. There is, however, an urgent need for a synthetic strategy capable of preparing hybrid AMNPs with fine-tuned structural and compositional complexities. Herein, we report a new paradigm for the controllable synthesis of polymer/metal AMNPs with well-controlled size, shape, composition, and morphology by utilizing interfacial polymerization. The hybrid AMNPs display a new level of structural–architectural sophistication, such as controlled domain size and the number of each component of AMNPs. The approach is simple, versatile, cost-effective, and scalable for synthesizing large quantities of AMNPs. Our method may pave a new route to the design and synthesis of advanced breeds of building blocks for functional materials and devices.

Controllable self-assembly of nanoscale building blocks into larger specific structures provides an effective route for the fabrication of new materials with unique optical, electronic, and magnetic properties. The ability of nanoparticles (NPs) to self-assemble like molecules is opening new research frontiers in nanoscience and nanotechnology. We present a new class of amphiphilic “colloidal molecules” (ACMs) composed of inorganic NPs tethered with amphiphilic linear block copolymers (BCPs). Driven by the conformational changes of tethered BCP chains, such ACMs can self-assemble into well-defined vesicular and tubular nanostructures comprising a monolayer shell of hexagonally packed NPs in selective solvents. The morphologies and geometries of these assemblies can be controlled by the size of NPs and molecular weight of BCPs. Our approach also allows us to control the interparticle distance, thus fine-tuning the plasmonic properties of the assemblies of metal NPs. This strategy provides a general means to design new building blocks for assembling novel functional materials and devices.

This communication describes a one-step strategy for the facile synthesis of polymer–Au patchy particles (PPs) and Au nanocups using the interfacial reactions.

This communication describes a novel strategy for the continuous microfluidic generation of highly monodispersed particle-coated microbubbles using temperature-dependent dissolution of carbon dioxide.

This communication describes a novel strategy for the synthesis of silica Janus particles with controlled shape and functionality using a facile wet-chemical approach.

Amphiphilic plasmonic micelle-like nanoparticles (APMNs) composed of gold nanoparticles (AuNPs) and amphiphilic block copolymers (BCPs) structurally resemble polymer micelles with well-defined architectures and chemistry. The APMNs can be potentially considered as a prototype for modeling a higher-level self-assembly of micelles. The understanding of such secondary self-assembly is of particular importance for the bottom-up design of new hierarchical nanostructures. This article describes the self-assembly, modeling, and applications of APMN assemblies in selective solvents. In a mixture of water/tetrahydrofuran, APMNs assembled into various superstructures, including unimolecular micelles, clusters with controlled number of APMNs, and vesicles, depending on the lengths of polymer tethers and the sizes of AuNP cores. The delicate interplay of entropy and enthalpy contributions to the overall free energy associated with the assembly process, which is strongly dependent on the spherical architecture of APMNs, yields an assembly diagram that is different from the assembly of linear BCPs. Our experimental and computational studies suggested that the morphologies of assemblies were largely determined by the deformability of the effective nanoparticles (that is, nanoparticles together with tethered chains as a whole). The assemblies of APMNs resulted in strong absorption in near-infrared range due to the remarkable plasmonic coupling of Au cores, thus facilitating their biomedical applications in bioimaging and photothermal therapy of cancer.

This communication reports the amphiphilic block copolymer driven self-assembly of Au nanoflowers into nanoparticle vesicles and the near-infrared light triggered release of hydrophilic molecules encapsulated in vesicles.

This communication describes a one-step strategy for the facile synthesis of polymer–Au patchy particles (PPs) and Au nanocups using the interfacial reactions.

This communication describes a novel strategy for the continuous microfluidic generation of highly monodispersed particle-coated microbubbles using temperature-dependent dissolution of carbon dioxide.

Nature offers a plethora of astonishing examples of shapes and functions from the aspects of both simplicity and complexity. The creation of synthetic systems that can morph in a controlled manner as seen in nature is of paramount importance in many fields of fundamental and applied sciences. The tremendous interest in self-shaping materials stems from a wide range of applications for these materials, ranging from biomedical devices to aircraft design. This review article highlights recent advances in understanding and designing thin, sheet-like soft materials that can transform into complex three-dimensional structures in a controlled manner by modulating the internal stresses. We review the general principles underlying shape transformation phenomena in natural and synthetic systems, and the significant achievements in fabricating self-shaping of soft materials via representative examples. We conclude with a discussion on the challenges facing the field, and future directions from the perspective of theoretical and experimental methodology and interdisciplinary applications.

This communication describes a facile method for the synthesis of conical-shaped Au nanoparticles with a hollow cavity by combining interfacial reaction and ultrasonic cavitation. The Au nanocones showed an enhancement factor of 7.7 × 108 in surface enhanced Raman scattering (SERS) detection.

In this communication, we report a composite macroporous hydrogel sheet that can rapidly transform into multiple 3D shapes in response to near-infrared (NIR) light on demand. The transformation relies on the photo-thermal-induced asymmetric shrinking of the hydrogel material, which is further verified by finite element modeling.

A combination of a microfluidic technique and laser-triggered reactions has been developed to fabricate functional gas-filled capsules (GFCs) on-demand with applications such as a pressure sensor. This method involves (i) the generation of monodispersed alginate microcapsules containing ammonium bicarbonate (AB) as gas resource and gold nanorods as a heating resource, in a microfluidic device; and (ii) the near-infrared light-triggered generation of gases from the AB-containing microcapsules and simultaneous encapsulation of the gases in an alginate shell to produce GFCs. Various functional substances such as dyes, quantum dots, and magnetic nanoparticles can be introduced into the shell of the GFCs to impart the system with multifunctionality. We further demonstrated the use of the GFCs as pressure sensors capable of sensing the variation in the pressure of environment.

This communication describes a novel strategy for the synthesis of silica Janus particles with controlled shape and functionality using a facile wet-chemical approach.