ACS Materials Au最新文献

The nucleus plays a central role in eukaryotic cell survival by regulating essential processes. This makes it a strategic target for disrupting tumor growth in cancer therapy. Conventional nucleus-directed anticancer agents, including doxorubicin (Dox), have demonstrated effectiveness in treatment but face challenges related to poor cellular uptake and nuclear localization. To overcome these limitations, nanoparticle-based systems have been explored. In this study, α-synuclein-gold nanoparticle conjugates (αS-AuNPs) were employed as an intracellular drug delivery system for nuclear-targeted cancer therapy. αS, an intrinsically disordered protein, facilitates cellular uptake and nuclear accumulation. Dox was linked to αS-(Y136C)-AuNP via a heat-labile cross-linker, enabling controlled drug release upon near-infrared (NIR) irradiation. The photothermal effect of AuNPs induced localized hyperthermia, cleaving the linker. This facilitated the release of Dox directly into the nucleus, thereby enhancing its anticancer efficacy. This study demonstrates that Dox-αS-AuNP represents a promising nucleus-targeted drug delivery system for controlled and efficient cancer therapy.

The synergy between graphene and ZnO in creating hybrid nanomaterials with novel properties of interest for the technological industry requires the development of processes and techniques that enable their precise production at the nanoscale. Therefore, understanding the atomic and molecular mechanisms that lead to their creation is imperative for controlling each involved step in their formation, enhancing their efficiency. This work sheds light on the first atomic layer half-cycle for the growth of ZnO on graphene with a hydroxyl-functionalized monovacancy. We performed quantum mechanical calculations, considering a trapping-mediated mechanism and diethylzinc (DEZ) as the precursor. The results suggest that neighboring hydroxyl groups facilitate DEZ adsorption and minimize the activation energy. This is linked to the role of hydroxyl groups in the formation of noncovalent interactions such as weak van der Waals and C-H···O and O-H···O hydrogen bonds, which stabilize the systems and facilitate the first partial reaction. By comparing the response in systems with one, two, and three hydroxyl groups, it was found that as these functional groups increased in quantity, the reactions were both thermodynamically and kinetically more favorable. Thus, it can be concluded that incorporating hydroxyl groups on graphene through pretreatment may considerably increase the initial growth rate of ZnO.

Copper sulfides represent a broad range of chemical compounds, including naturally occurring minerals and wet-chemically synthesized nanoparticles. Tailoring the size, shape, and chemical composition of Cu_2‑x S nanoparticles enables the tuning of their optical and electronic properties allowing the switch between semiconducting and plasmonic characteristics. While the sulfidation of metals and metal oxides can even occur spontaneously under ambient storage conditions, the targeted synthesis of Cu_2‑x S nanoparticles mostly relies on the use of inorganic sulfur compounds. Inspired by the natural sulfidation reactions, a novel approach is developed in this paper to transform sacrificial Cu₂O nanooctahedra by a short-chain organic thiol (β-mercaptoethanol) into spherical Cu₂S superstructures consisting of phase-pure Cu₂S quantum dots. The optical and photoelectrochemical properties are thoroughly investigated and supplemented by advanced electron microscopy analysis to identify the phase of the superstructure building blocks. Structural and surface analyses reveal that the superstructures are composed of small (4-5 nm) Cu₂S quantum dots spatially separated by a thin amorphous ligand layer. The results highlight the dual role of β-mercaptoethanol serving both as a sulfur source and as a stabilizing ligand upon superstructure formation. To synthesize semiconductor/metal multicomponent nanostructures, the surface of the superstructures is decorated with Au nanograins initiated by the photoreduction of aqueous Au³⁺ ions. Upon the fabrication of working electrodes from the developed superstructures, the p-type nature of the Cu₂S is demonstrated by open-circuit potentiometry. Superstructures supply negative photocurrent under UV irradiation, which can be further enhanced by the presence of Au nanograins. Using the developed synthetic method, phase-pure photofunctional nanomaterials can be prepared by the sulfidation of cuprous oxide in a controlled manner.

Inhibiting unwanted protein–protein interactions (PPIs) by targeting extensive protein binding surfaces presents a significant challenge. Macro-ligands offer a promising approach, but traditional covalent functionalization strategies often suffer from synthetic complexity, particularly in controlling the spatial arrangement of binding moieties. This study introduces a new method for macro-ligand design based on the noncovalent, modular self-assembly of functional units within an inert dendrimer scaffold. Although these units are embedded within the dendrimer in a random arrangement, they are mobile and free to move. As such, when a target protein is introduced, these binding units can undergo a self-organization process to optimize their spatial distribution and maximize cooperative interactions with the protein’s binding surface. This dynamic process is controlled by the protein, as it guides and controls the formation of its own optimized macromolecular ligand. When sensor units are combined and included in the assembly process, real-time monitoring and quantification of binding can be detected and quantified. This study details the synthetic methodology employed for the preparation of the component parts and their self-assembly into dendrimer complexes. Subsequent binding assays using cytochrome-c as the target protein, and associated dendrimer complexes, exhibited binding affinities in the nanomolar (nM) range.

Many metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) can form crystals amenable to single-crystal X-ray diffraction analysis. It makes them suitable for Hirshfeld atom refinement (HAR) which has a well-established advantage over the Independent Atom Model in terms of the determination of hydrogen atom positions in the case of molecular crystals. However, up until now, the application of HAR to crystals of polymeric compounds such as MOFs and COFs has not been thoroughly investigated. This study of X-ray data sets collected for 20 MOFs, COFs and other coordination polymers is designed to provide an extensive assessment of two different implementations of HAR with respect to hydrogen positions and refinement statistics, given varying data quality.

Despite growing interest in multifunctional nanomaterials for biomedical and sensing applications, there remains a notable scarcity of hybrid nanoparticles that integrate semiconducting, fluorescent, and biocompatible components into a single, tunable platform. The sulvanite Cu₃VS₄, a ternary chalcogenide with demonstrated near-infrared absorption and photothermal conversion properties, has been relatively underexplored compared to more conventional binary chalcogenides in such hybrid constructs. In this work, core–shell–shell structured Cu₃VS₄@SiO₂@Tb/GMP nanoparticles exhibiting green luminescence have been designed and fabricated. The multistep synthesis process involved Cu₃VS₄ synthesis and pretreatment followed by the addition of the silica shell, and last by simultaneous terbium (Tb) coordination and surface modification with guanosine monophosphate. The morphology, structure, and optical properties of the nanoparticles were systematically characterized using transmission electron microscopy, X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, and photoluminescence spectroscopy. Structural analysis confirmed the formation of well-defined spherical nanostructures with homogeneous dual-shell architecture and an average particle diameter of 50 nm. Upon excitation at 295 nm, the nanoparticles demonstrated intense green emission attributed to the characteristic electronic transitions of the Tb³⁺ ions. Furthermore, the incorporation of GMP enhanced the fluorescence stability of the nanoparticles, making them promising candidates for applications in bioimaging, optoelectronics, or sensing. These findings suggest that the developed nanoparticles hold significant potential for diverse applications, including bioimaging, optoelectronic devices, and fluorescence-based sensing platforms.

Bacteria employ cyclopropane motifs as bioisosteres for unsaturations to modulate lipid bilayer fluidity and protect cellular membranes under environmental stress. Drawing inspiration from this biological strategy, we investigated how cyclopropanation impacts the thermophysical properties of lipid-inspired ionic liquids. We synthesized a series of imidazolium-based ionic liquids incorporating cyclopropanated derivatives of three renewable terpenoids: phytol, farnesol, and geraniol. Through an integrated approach combining property-driven design, thermophysical analysis, X-ray crystallography, and computational modeling, we systematically examined how these structural modifications influence quantitative structure–property relationships. Our findings demonstrate that ionic liquids with long alkyl appendages respond to side-chain modifications─particularly the synergistic combination of cyclopropanation and branching─in a manner that mimics homeoviscous adaptation in living organisms. The strategic incorporation of cyclopropyl moieties combined with chiral methyl branching produced dramatic melting point depressions, with phytol-derived ionic liquids achieving the lowest melting points reported to date for these bioinspired materials. This effectiveness results from positioning these structural elements within the symmetry-breaking region of alkyl chains, where they maximally disrupt molecular packing and enhance fluidity. X-ray crystallographic analysis of a cyclopropanated citronellyl-based ionic liquid revealed that the cyclopropyl ring induces significant conformational distortions that prevent efficient molecular organization. The use of terpenoids from the chiral pool as starting materials imparts inherent sustainability to these ILs. Enantiopure ILs can be synthesized from renewable feedstocks like phytol and citronellol while exploiting bioinspired structural design principles. This work provides new insights into IL structure–property relationships that both complement and extend previous discoveries, establishing a framework for the rational design of lipidic ionic liquid systems with enhanced fluidity and chemical stability from renewable resources.

The disposal of wind turbine blade (WTB) waste poses a significant environmental challenge due to its high volume and complex composition. This study introduces an innovative approach to address this issue by repurposing WTB-derived glass fibers (GF) into high-performance polyacrylonitrile (PAN)-GF composite fibers through a scalable dry-jet wet spinning and forced assembly process. By integrating alternating layers of PAN and PAN-GF, layer thickness was precisely controlled to the micrometer scale, ensuring enhanced GF dispersion and improved orientation through shear stress at layer interfaces. The individual layer thickness in the multilayered PAN-GF fibers decreased progressively with an increasing number of layers, with 32-layered fibers exhibiting comparatively thicker layers, while 256-layered fibers demonstrated significantly thinner layers. The effects of WTB-GF incorporation on the thermal and mechanical properties of PAN fibers were examined using tensile testing and thermogravimetric analysis (TGA). Using GF loadings of 1–4 wt %, the 256-layered composite fibers demonstrated remarkable mechanical improvements, with stiffness (modulus) increasing by 54.7% from 15.10 to 23.37 GPa and tensile strength rising by 27.2% from 521.71 to 663.66 MPa compared to pure PAN fibers. TGA results indicate that increasing the GF content leads to higher residual weight at 900 °C, reflecting enhanced thermal stability and greater char yield. The 256-layered 10PAN-4GF fibers showed the highest residual mass (41.23 wt %), highlighting the significant contribution of GF reinforcement to thermal stabilization. Heat treatment further transformed these precursor fibers into carbonized fibers (CF) with exceptional thermal stability and performance under extreme conditions. This process highlights a sustainable pathway for reusing WTB waste and producing advanced composite fibers, making them ideal candidates for demanding applications such as aerospace and space exploration.