We have developed a new class of plasmonic vesicular nanostructures assembled from amphiphilic gold nanocrystals with mixed polymer brush coatings. One major finding is that the integration of gold nanocrystals (nanoparticles and nanorods) with two types of chemically distinct polymer grafts, which are analogous to block copolymers as a whole, creates a new type of hybrid building block inheriting the amphiphilicity-driven self-assembly of block copolymers to form vesicular structures and the plasmonic properties of the nanocrystals. In contrast to other vesicular structures, the disruption of the plasmonic vesicles can be triggered by stimulus mechanisms inherent to either the polymer or the nanocrystal. Recent advances in nanocrystal synthesis and controlled surface-initiated polymerization have opened a wealth of possibilities for expanding this concept to other types of nanocrystals and integrating different types of nanocrystals into multifunctional vesicles. The development of multifunctional vesicles containing stimuli-responsive polymers could enable their broader applications in biosensing, multimodality imaging, and theragnostic nanomedicine.

We report a new class of amphiphilic nanocrystals with mixed polymer brush coatings, which can spontaneously assemble into two-dimensional arrays at oil-water interfaces. The plasmon coupling of gold nanoparticles and nanorods in the assembly can be reversibly modulated by conformational changes of the stimuli-responsive polymer brushes. Amphiphilic gold nanocrystals (nanoparticles and nanorods) with mixed polymer brushes were synthesized via sequential "grafting to" (ligand exchange) and "grafting from" (surface initiated atom transfer radical polymerization) reactions. The integration of "grafting to" and "grafting from" reactions offers great flexibility for the surface modification of the nanocrystal scaffolds, allowing the combination of polymers with distinctly different properties on well-defined nanocrystals. For nanocrystals with poly(ethylene glycol) and poly(methyl methacrylate) coatings, the collective plasmonic property of the assembly can be tailored by changing solvent quality. In the case of the amphiphilic nanocrystal with poly(ethylene glycol) and poly(2-(diethylamino)ethyl methacrylate), the pH-sensitivity of poly(2-(diethylamino)ethyl methacrylate) provides an additional means to reversibly tune the assembly by varying the pH. All of the components, including nanocrystals, materials for self-assembled monolayers (polymers and biomacromolecules) on nanocrystal surfaces, and monomers suitable for surface-initiated living radical polymerization, in this construct have a wealth of possibilities available, indicating the potential of our strategy for developing hybrid materials with integrated and collective functionalities.

Plasmonics has remained a prominent and growing field over the past several decades. The coupling of various chemical and photo phenomenon has sparked considerable interest in plasmon‐mediated photocatalysis. Given plasmonic photocatalysis has only been developed for a relatively short period, considerable progress has been made in improving the absorption across the full solar spectrum and the efficiency of photo‐generated charge carrier separation. With recent advances in fundamental (i.e., mechanisms) and experimental studies (i.e., the influence of size, geometry, surrounding dielectric field, etc.) on plasmon‐mediated photocatalysis, the rational design and synthesis of metal/semiconductor hybrid nanostructure photocatalysts has been realized. This review seeks to highlight the recent impressive developments in plasmon‐mediated photocatalytic mechanisms (i.e., Schottky junction, direct electron transfer, enhanced local electric field, plasmon resonant energy transfer, and scattering and heating effects), summarize a set of factors (i.e., size, geometry, dielectric environment, loading amount and composition of plasmonic metal, and nanostructure and properties of semiconductors) that largely affect plasmonic photocatalysis, and finally conclude with a perspective on future directions within this rich field of research.

We first time report a general strategy for one-step fabrication of a ZIF-8 MOF/RGO hydrogel, with the synergistic effects of chemical reduction and cross-linking by metal ions.

Binary wettability patterned surfaces with extremely high wetting contrasts can be found in nature on living creatures. They offer a versatile platform for microfluidic management. In this work, a facile approach to fabricating erasable and rewritable surface patterns with extreme wettability contrasts (superhydrophilic/superhydrophobic) on a TiO2 nanotube array (TNA) surface through self-assembly and photocatalytic lithography is reported. The multifunctional micropatterned superhydrophobic TNA surface can act as a 2D scaffold for site-selective cell immobilization and reversible protein absorption. Most importantly, such a high-contrast wettability template can be used to construct various well-defined 3D functional patterns, such as calcium phosphate, silver nanoparticles, drugs, and biomolecules in a highly selective manner. The 3D functional patterns would be a versatile platform in a wide range of applications, especially for biomedical devices (e.g., high-throughput molecular sensing, targeted antibacterials, and drug delivery). In a proof-of-concept study, the surface-enhanced Raman scattering and antibacterial performance of the fabricated 3D AgNP@TNA pattern, and the targeted drug delivery for site-specific and high-sensitivity cancer cell assays was investigated.

Inspired by hierarchical protein self-assembly in biological systems, the self-assembly of nanoparticles into superstructures has attracted much attention because of potential applications of these superstructures in the fields such as electronic or optical materials and novel nanodevices. [1][2][3][4][5] Template-free self-assembly of nanoparticles with anisotropic interactions is of particular interest because it can lead to tailor-made complex superstructures. [1,[6][7][8] In fact, Janus nanoparticles are nano-objects with anisotropic interactions.[9] The facile preparation, applications, and self-assembly of Janus nanoparticles have attracted extensive interest, and Janus particles with various sizes, structures, and compositions have been recently reported. [10][11][12][13][14][15][16][17][18] Several kinds of Janus particles are capable of self-assembling into regular superstructures. For example, Müller and co-workers reported that amphiphilic Janus micelles prepared from ABC triblock copolymers could self-assemble into spherical supermicelles. [19,20] Granick and co-workers reported that amphiphilic and zwitterionic Janus colloidal spheres could assemble in water to form ordered clusters. [21,22] In a recent study, we prepared Janus nanoparticles by using hybrid organic/inorganic nanotubes as a desymmetrization tool and the as-prepared amphiphilic Janus nanoparticles self-assembled into narrowly size-distributed flowerlike supermicelles in water.[23] Despite these results, assembly of Janus nanoparticles into superstructures other than spherical supermicelles or clusters, such as nanowires, [24] tubular and sheetlike superstructures, still remains challenging.Herein, we report a novel mechanism for the formation of polymeric Janus particles from mixed-shell micelles (MSMs) and the template-free self-assembly of the Janus particles into tubular superstructures and nanosheets. Micelles with mixed P2 VN/PEO shells were prepared by noncovalent crosslinking of poly(acrylic acid) (PAA) blocks by addition of 1,2-propanediamine (PDA) to a solution of PEO 3500 -b-PAA 3800 /P2VN 38000 -b-PAA 24000 (1:1 (w/w), PEO = poly(ethylene oxide), P2VN = poly(2-vinyl naphthalene), and the subscripts denote the molecular weights of the respective blocks) in DMF (Figure 1 a). The molar ratio of AA/PDA was 1:5, and the total polymer concentration was 1.0 mg mL À1 . MSMs with PEO/P2VN as the mixed shell and a PDAcross-linked PAA network as the core were thus formed by noncovalent cross-linking. After switching the solvent from DMF to water (pH 7) by using dialysis, P2 VN in the mixed shell collapsed into separated microdomains (Figure 1 b). In water, P2 VN microdomains were surrounded and protected by solvated PEO chains so that the MSMs were individually dispersed. By decreasing the pH value of the aqueous solution to 3.1, intramicellar complexation occurred between PEO and PAA (Figure 1 c), which resulted in an asymmetric intramicellar phase separation between the PEO/PAA complex and P2VN. As a result, amphiphilic Janus nanopar...

Here we report one-pot synthesis of tetraphenylethene-based tetracationic dicyclophane (1) and its self-assembly behaviors with aggregation-induced emission (AIE) and light-harvesting function. Confirmed by X-ray crystal structure and high resolution transmission electron microscopy, this tetracationic dicyclophane can self-assemble into a 3D supramolecular framework to form crystalline nanospheres (2) finally, which exhibits a strong emission (ΦF = 97.7%) via AIE effect in aqueous solution. Interestingly, AIE-active 2 as a single-molecule-based fluorescent supramolecular platform can encapsulate an organic dye (e.g., Nile red) to form light-harvesting nanospheres (3) further with a large red-shift (Δλ = ∼70 nm), highly efficient energy-transfer ability (ΦET = 77.5%), and high antenna effect (14.3).

Nanoparticle drug formulations have been extensively investigated, developed, and in some cases, approved by the Food and Drug Administration (FDA). Synergistic combinations of drugs having distinct tumor-inhibiting mechanisms and non-overlapping toxicity can circumvent the issue of treatment resistance and may be essential for effective anti-cancer therapy. At the same time, co-delivery of a combined regimen by a single nanocarrier presents a challenge due to differences in solubility, molecular weight, functional groups and encapsulation conditions between the two drugs. This review discusses cellular and microenvironment mechanisms behind treatment resistance and nanotechnology-based solutions for effective anti-cancer therapy. Co-loading or cascade delivery of multiple drugs using of polymeric nanoparticles, polymer-drug conjugates and lipid nanoparticles will be discussed along with lipid-coated drug nanoparticles developed by our lab and perspectives on combination therapy.