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Manipulation and Deposition of Complex, Functional Block Copolymer Nanostructures using Optical Tweezers
摘要： Block copolymer self-assembly has enabled the creation of a range of solution-phase nanostructures with applications from optoelectronics and biomedicine to catalysis. However, to incorporate such materials into devices a method that facilitates their precise manipulation and deposition is desirable. Herein we describe how optical tweezers can be used to trap, manipulate, and pattern individual cylindrical micelles and larger hybrid micellar materials. Through the combination of TIRF imaging and optical trapping we can precisely control the three-dimensional motion of individual cylindrical block copolymer micelles in solution, enabling the creation of customizable arrays. We also demonstrate that dynamic holographic assembly enables the creation of ordered customizable arrays of complex hybrid block copolymer structures. By creating a program which automatically identifies, traps and then deposits multiple assemblies simultaneously we have been able to dramatically speed up this normally slow process, enabling the fabrication of arrays of hybrid structures containing hundreds of assemblies in minutes rather than hours.
关键词： optical trapping,directed assembly,block copolymers,self-assembly,nanofibers
更新于2025-11-21 11:24:58
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Self-Assembled Nanostructures of Red Fluorescent Amphiphilic Block Copolymers as Both Imaging Probes and Drug Carriers
摘要： We report a red-?uorescent drug delivery system formed by biodegradable and biocompatible amphiphilic A-B-A block copolymers. Each polymer consists of a red ?uorescent dye covalently bonded in the middle of hydrophobic block (B) of polylactone, tethered at both ends with poly[(oligo ethylene glycol) methyl ether methacrylate] (POEGMA) as the hydrophilic block. Two types of polylactones, i.e., semicrystalline poly(ε-caprolactone) (PCL) and amorphous poly(δ-decalactone) (PDL), respectively, were incorporated as the hydrophobic segment in the block copolymers. Using transmission electron microscopy, we characterized the self-assembled nanostructures formed by these amphiphilic block copolymers in mixtures of water/tetrahydrofuran or water/dimethylformamide. All of these polymers remained highly ?uorescent in water, although some extent of aggregation-induced ?uorescence quenching was still observed. Among the three types of polymers presented here, the polymer (RPO-3) containing an amorphous block of PDL showed the highest drug-loading capacity and the largest extent of drug release in acidic media. RPO-3 micelles loaded with doxorubicin as a model of anticancer drug showed sustainable intracellular release and cytotoxicity against HeLa cells.
关键词： self-assembly,drug delivery,polymer,?uorescence,bioimaging
更新于2025-11-21 11:08:12
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From colloidal CdSe quantum dots to microscale optically anisotropic supercrystals through bottom-up self-assembly
摘要： The development of fabrication techniques for novel nanostructured materials is one of the key tasks of modern materials science. One pathway to successfully complete this task is the bottom-up assembly of colloidal nanoparticles into ordered superstructures, possessing both the properties of individual nanoparticles and further novel properties resulting from their interactions. However, nanoparticle self-assembly depends on a variety of parameters, which makes the precise control of this process a complicated problem. Here, the time course of quantum dot (QD) self-assembly into ordered superstructures has been analyzed, along with the evolution of their morphological and optical properties. QD self-assembly occurs through two distinct stages (homo- and hetero-geneous), leading to the formation of supercrystals with a layered morphology. Analysis of the optical properties throughout the superstructures’ growth has shown that the absorption and photoluminescence (PL) bands are blue shifted, retaining almost the same PL lifetimes as in the initial QD solution. The supercrystals formed possess a further unique optical property caused by their layered morphology; namely, a four-fold symmetry characterized by strong birefringence. Such supercrystals may be used for the fabrication of microscale optical paths with high extinction coefficients and specific polarization properties for novel optoelectronic devices.
关键词： optical anisotropy,nanostructured materials,birefringence,self-assembly,quantum dots,supercrystals
更新于2025-11-21 11:08:12
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A Fluorescent Supramolecular Biosensor for Bacterial Detection via Binding-Induced Changes in Coiled-Coil Molecular Assembly
摘要： The essential elements required for any sensors are a receptor, a signal converter, and a detector. Here, we report the construction of bacterial biosensors in which all of the required biosensor elements are furnished in one supramolecular assembly. The supramolecular biosensor is based on a double-layered octa-helical coiled-coil peptide assembly that contains tetravalent bioreceptors on the outer surface and environment-sensitive fluorophores in the core. The signal conversion takes advantage of the noncovalent and reversible nature of the self-assembled system, i.e., the multivalent binding of bacteria induces conformational changes in the supramolecular state, which is translated into differential fluorescence emissions. We show that fluorescent supramolecular biosensors (fSBs) can selectively detect E. coli over other bacteria. Because the fSBs were resistant to heat-induced denaturation, they retained their bacterial-sensing capability even at an elevated temperature (50 ℃). Biosensors based on responsive supramolecular assemblies can be further developed to detect various large and flat biological objects and biomacromolecules.
关键词： Escherichia coli,Supramolecule,Biosensor,Bacteria,Self-assembly,Peptide-based probe
更新于2025-11-21 11:08:12
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Constructing electrostatic self-assembled 2D/2D ultra-thin ZnIn2S4/protonated g-C3N4 heterojunctions for excellent photocatalytic performance under visible light
摘要： 2D/2D ultra-thin ZnIn2S4/protonated g-C3N4 nanocomposites (ZnIn2S4/pCN) are fabricated by electrostatic self-assembly strategy between negatively charged 2D ultra-thin ZnIn2S4 nanosheets and 2D protonated g-C3N4 nanosheets. The optimized ZnIn2S4/pCN (5:3) shows excellent photocatalytic activity toward H2 production (~8601.16 μmol·g?1·h?1) under visible light. In addition, ZnIn2S4/pCN also exhibits superior visible-light-driven photocatalytic tetracycline degradation efficiency, about ~4.13 and ~2.28 times higher than protonated g-C3N4 and ultra-thin ZnIn2S4, respectively. The optimal ZnIn2S4/pCN (5:3) also has good photostability. The excellent photocatalytic activity of ZnIn2S4/pCN can be attributed to the unique 2D/2D heterojunctions, which are obtained by electrostatic self-assembly. The intimate interfacial contact and larger contact areas promote the separation and migration of photogenerated carriers, which contribute to the improvement of photocatalytic activity and photostability. Our research on the 2D/2D nanocomposites provides a scalable solution for the research of efficient and active photocatalysts.
关键词： protonated g-C3N4,ultra-thin ZnIn2S4 nanosheets,electrostatic self-assembly,2D/2D
更新于2025-11-19 16:46:39
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Self-assembling Non-conjugated Poly(amide-imide) into Thermoresponsive Nanovesicles with Unexpected Red fluorescence for Bioimaging
摘要： Non-conjugated red fluorescent polymers have been increasingly studied to improve the biocompatibility and penetration depth over conventional fluorescent materials. However, the accessibility of such polymers remains challenging due to the scarcity of non-conjugated fluorophores and lacking relevant mechanism of red-shifted fluorescence. Herein, we discovered that the combination of hydrogen bonding and π-π stacking interactions provides non-conjugated poly(amide-imide) with a large bathochromic shift (> 100 nm) from blue-green fluorescence to red emission. The amphiphilic PEGylated poly(amide-imide) derived from in-situ PEGylation self-assembled into nanovesicles in water, which isolated the aminosuccinimide fluorophore from the solvents and suppressed the hydrogen bonds formation between aminosuccinimide fluorophores and water. Therefore, the fluorescence of PEGylated poly(amide-imide) in water was soundly retained. Furthermore, the strong hydrogen bonding and hydrophobic interactions with water provided PEGylated poly(amide-imide) with a reversible thermoresponsiveness and presented a concentration-dependent behavior. Finally, accompanied with the excellent biostability and photostability, PEGylated poly(amide-imide) exhibited as a good candidate for cell imaging.
关键词： poly(amide-imide),red-shifted fluorescence,self-assembly,bioimaging,nanovesicles
更新于2025-11-14 17:04:02
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Facile Interface Self-Assembly of Gold Nanoparticles as Surface-Enhanced Raman Scattering Substrate for Monitoring the Reduction of p-Nitrophenol
摘要： A facile interface self-assembly method was proposed to fabricate the gold monolayer film without any specific molecular cross-linkers. The film was served as a surface-enhanced Raman scattering substrate, which exhibited high enhancement and reproducibility to the 1 × 10-9 M rhodamine 6G aqueous solution. Based on the substrate, the in situ and real-time monitoring for the reduction of p-nitrophenol to p-aminophenol was demonstrated successfully.
关键词： Interfaces,Surface-enhanced Raman scattering,Self-assembly,Nanoparticles
更新于2025-11-14 17:03:37
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Tuneable Emission of Polyhedral Oligomeric Silsesquioxane‐ Based Nanostructures Self‐Assembled in the Presence of Europium(III) Ions: Reversible trans‐to‐cis Isomerization
摘要： Hybrids nanostructures with switchable and reversible “blue-red-green” emission were efficiently synthesized. The Polyhedral Oligomeric Silsesquioxane (POSS) behaves as a directional nano-cage for the terpyridine-based organic ligands allowing an easy complexation of Europium (III) cations. The complexes were characterized via UV-Vis and fluorescence spectroscopies and the stoichiometry was also confirmed via 1H NMR investigation. The octafunctionalized nano-cages allow forming novel self-assembled 3D architectures in presence of the lanthanide cation displaying a red-emission of particular intensity especially in solid state. The presence of an alkenyl group bridging the inorganic core to the organic moiety was employed to tune the emission properties via trans-cis isomerization of the double bond. In the case of O-POSS nanocages this isomerization was monitored also in presence of Eu(III) cations and was accompanied by an evident modification of the colour which passed from blue (trans-O-POSS) to red (Eu@trans-O-POSS) and finally to green (cis-O-POSS) as consequence of the release of the metal cations. This behaviour, together with the easy dispersion of the dry powder and the possibility of coating it as a film in presence of small amount of solvent, makes the emitting solid promising for applications in materials science.
关键词： europium,luminescence,silsesquioxanes,isomerization,self-assembly
更新于2025-11-14 15:32:45
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Directed Nanoscale Self-assembly of Natural Photosystems on Nitrogen-doped Carbon Nanotubes for Solar Energy Harvesting
摘要： Natural photosystems (PSs) have received much attention as a biological solar energy harvester because of their high quantum efficiency for energy transfer. However, the PSs hybridized with solid electrodes exhibit low light-harvesting efficiencies because of poor interface properties and random orientations of PSs, all of which interfere with efficient charge extraction and transfer. Herein, we report the linker-free, oriented self-assembly of natural PSs with nitrogen-doped carbon nanotubes (NCNTs) via electrostatic interaction. Protonated nitrogen-doped sites on the NCNTs facilitate spontaneous immobilization of the negatively charged stroma side of PSs, which provides a favorable orientation for electron transfer without electrically insulating polymer linkers. The resulting PS/NCNT hybrids exhibit a photocurrent density of 1.25 ± 0.08 μA cm-2, which is much higher than that of PS/CNT hybrids stabilized with polyethylenimine (0.60 ± 0.01 μA cm-2) and sodium dodecyl sulfate (0.14 ± 0.01 μA cm-2), respectively. This work emphasizes the importance of the linker-free assembly of PSs into well-oriented hybrid structures to construct an efficient light-harvesting electrode.
关键词： Light-harvesting,Electrostatic interaction,Photosystems,Nitrogen-doped carbon nanotubes,Self-assembly
更新于2025-11-14 15:29:11
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Self-Assembled Ordered Three-Phase Au-BaTiO <sub/>3</sub> -ZnO Vertically Aligned Nanocomposites Achieved by a Templating Method
摘要： Complex multiphase nanocomposite designs present enormous opportunities for developing next-generation integrated photonic and electronic devices. Here, a unique three-phase nanostructure combining a ferroelectric BaTiO3, a wide-bandgap semiconductor of ZnO, and a plasmonic metal of Au toward multifunctionalities is demonstrated. By a novel two-step templated growth, a highly ordered Au–BaTiO3–ZnO nanocomposite in a unique “nanoman”-like form, i.e., self-assembled ZnO nanopillars and Au nanopillars in a BaTiO3 matrix, is realized, and is very different from the random three-phase ones with randomly arranged Au nanoparticles and ZnO nanopillars in the BaTiO3 matrix. The ordered three-phase “nanoman”-like structure provides unique functionalities such as obvious hyperbolic dispersion in the visible and near-infrared regime enabled by the highly anisotropic nanostructures compared to other random structures. Such a self-assembled and ordered three-phase nanocomposite is obtained through a combination of vapor–liquid–solid (VLS) and two-phase epitaxy growth mechanisms. The study opens up new possibilities in the design, growth, and application of multiphase structures and provides a new approach to engineer the ordering of complex nanocomposite systems with unprecedented control over electron–light–matter interactions at the nanoscale.
关键词： vertically aligned nanocomposites,plasmonics,epitaxial thin films,metamaterials,three-phase nanocomposites,self-assembly
更新于2025-10-22 19:40:53