ACS Publications最新文献

The integration of functional oxides with two-dimensional (2D) transition metal dichalcogenides (TMDs) is pivotal for next-generation electronics yet remains constrained by aggressive interfacial reactions and interdiffusion. Herein, we resolve the atomic-scale reaction kinetics at the Mn/MoS₂(0001) heterointerface by combining spherical aberration-corrected scanning transmission electron microscopy (STEM) with density functional theory (DFT) calculations. We identify a distinct temperature-dependent pathway that transforms destructive diffusion into precise phase engineering. At 500 °C, Mn cation intercalation serves as the primary driving force, inducing the nucleation of a metastable triclinic MnMoO₅ phase while concurrently triggering a local 2H-to-1T polymorphic transition. Crucially, this intercalation is confined to a self-limiting skin layer, evidenced by a ∼4% c-axis expansion. Elevating the thermal treatment to 600 °C promotes thermodynamic equilibration, facilitating the crystallization of the polar magnetic hexagonal Mn₂Mo₃O₈ phase and the reconstruction of an atomically sharp interface. These findings demonstrate a mechanism for exploiting reactive diffusion to synthesize high-quality, functional oxide/2D heterostructures with chemically distinct, sharp interfaces.

Platinum-based electrocatalysts exhibit exceptional intrinsic activity toward the hydrogen evolution reaction (HER), but their practical deployment in water electrolysis is hindered by nanoparticle agglomeration, carbon-support degradation, and weak metal-support interaction (MSI). Here, porous TiO₂ supports with systematically tunable anatase-rutile composition were synthesized using MIL-125 (Ti) as a metal-organic framework (MOF) template, followed by controlled calcination and chemical reduction to anchor uniformly dispersed Pt nanoparticles. Precise phase engineering strengthened MSI, most notably in Pt/TiO₂-500, which displayed a distinct negative shift in Pt 4f (-0.7 eV) and a positive shift in Ti 2p (+0.5 eV), indicating strong interfacial electronic coupling. This optimized interaction reduced charge-transfer resistance, yielded overpotentials of 34 mV and 84 mV at 10 and 50 mA cm^-2, and produced a Tafel slope of 32.6 mV dec^-1, comparable to or better than many state-of-the-art TiO₂-supported Pt electrocatalysts. Pt/TiO₂-500 also preserved 96.5% of its activity after 2000 potential cycles and maintained stable operation for over 100 h at 10 mA cm^-2, confirming its structural and electrochemical robustness. These results demonstrate that phase-engineered MOF-derived TiO₂ significantly reinforces MSI, suppresses Pt agglomeration, and accelerates interfacial charge-transfer kinetics. This work establishes a generalizable strategy for designing durable and high-performance Pt-based electrocatalysts for sustainable hydrogen production.

The work presents the development of a non-peptide fluorescent probe, NQ , for in vitro detection of chymotrypsin (Chy). Unlike traditional peptide-based probes that suffer from instability and enzymatic degradation, NQ incorporates hydrocinnamoyl chloride as a recognition group, offering enhanced stability under physiological conditions. Upon enzymatic cleavage by Chy, the probe releases a fluorogenic product (NQOH), generating a turn-on fluorescence signal. NQ exhibits a rapid initial response, with a distinguishable fluorescence signal generated within 10 min, and a low detection limit of 7.64 ng/mL. Although the enzymatic reaction reaches saturation over a period of 30-60 min, the rapid initial turn-on allows for rapid qualitative screening. A notable feature is the probe's large Stokes shift (177nm) combined with an efficient non-peptidic recognition group. This synergistic design significantly improves detection accuracy by minimizing background interference and resisting non-specific degradation in complex biological environments. The probe showed effective performance in HepG2 cell models, confirming its suitability for biological applications. This study underscores the value of non-peptide probe designs for fast and precise enzyme detection in complex biological environments.

Transition metal dichalcogenides (TMDs) have shown great potential in optoelectronic devices, such as phototransistors and photodetectors. However, TMD-based optoelectronic devices face notable limitations, primarily weak light absorption due to their atomically thin structure and short exciton-carrier lifetimes caused by strong excitonic effects. Constructing heterostructures (HSs) with TMDs and perovskites is an important strategy to overcome these challenges. Understanding charge transfer dynamics and interlayer recombination at the TMD/2D perovskite interface is essential but still lacking. Here, we prepared monolayer WS₂/2D perovskite HSs with varying n-values (n = 1, 2, and 4, n represents the number of inorganic octahedral layers between two adjacent organic spacers within the 2D perovskite structure) and systematically investigated the photogenerated carrier transfer and interlayer electron-hole recombination process. By employing the n = 1 2D perovskite film and selectively exciting monolayer WS₂, we observed ultrafast photogenerated hole transfer from monolayer WS₂ to the n = 1 2D perovskite film within 200 fs. Further, in the HS formed with the n = 4 2D perovskite film, upon selectively exciting the n = 4 2D perovskite film, we observed an ultrafast photogenerated electron transfer from the n = 4 2D perovskite film to monolayer WS₂, occurring within 2.5 ps. Finally, we found that as the n value increased, the reduced quantum confinement led to a significant increase in the interlayer electron-hole recombination lifetime within the 2D perovskite/monolayer WS₂ HSs, extending from 0.2 ns at n = 1 to 8.6 ns at n = 4. This study demonstrates that in TMD/2D perovskite HSs, ultrafast hole transfer from TMD to the 2D perovskite and efficient electron transfer from the 2D perovskite to TMD can both occur. Additionally, the interlayer electron-hole recombination lifetime can be modulated by quantum confinement effects. Our findings provide critical guidance for optimizing optoelectronic devices based on TMD/2D perovskite HSs.

Precise control of light-matter interactions is a cornerstone of next-generation technologies, from ultrasensitive biosensing and single-molecule tracking to the development of adaptive metamaterials. While small, symmetric nanostructures are well-understood, micrometer-scale plasmonic Janus particles (pJPs), comprising dielectric cores with thin metallic caps, exhibit complex optical properties due to their asymmetric structure. Despite widespread applications in active matter research, their orientation-dependent scattering properties remain largely unexplored. We introduce Fourier plane tomographic spectroscopy for simultaneous four-dimensional characterization of scattering from individual micrometer-scale particles across wavelength, incident angle, and scattering angle. Combining measurements with finite-element simulations, we identify discrete spectral markers in visible and near-infrared regions that evolve predictably with cap orientation. Spherical-harmonics decomposition reveals that these markers arise from three distinct multipolar modes up to fifth order: axial-propagating transverse-electric, transverse-propagating transverse-electric, and transverse-propagating axial-electric, with retardation-induced splitting. We observe progressive red-shifts and line width narrowing of higher-order resonances, demonstrating curvature's influence on mode dispersion. Orientation-specific scattering patterns exhibit polarization-dependent features enabling optical tracking of particle rotation. Beyond pJPs, this methodology establishes a general framework for characterizing asymmetric nanostructures of diverse material combinations and geometries, offering a toolkit for designing orientation-responsive nanoantennas, reconfigurable metasurfaces, active colloidal systems with tailored light-matter interactions, and high-precision optical tracking of particle rotation.

Silicon nitride has emerged as a promising photonic platform for integrated single-photon sources, yet the microscopic origin of the recently observed bright quantum emissions remains unclear. Using hybrid density functional theory, we show that the negatively charged N_SiV_N center (NV^-) in the C_1h configuration exhibits a linearly polarized zero phonon line (ZPL) at 2.46 eV, with a radiative lifetime of 9.01 ns and a high Debye-Waller (DW) factor of 33%. We further find that the C_1h configuration is prone to a pseudo-Jahn-Teller distortion, yielding two symmetrically equivalent defect structures that emit bright, linearly polarized ZPL at 1.80 eV with a lifetime of 10.17 ns and an increased DW factor of 41%. These nitrogen-vacancy-related defects explain the origins of visible quantum emissions, paving the way for deterministic and monolithically integrated silicon nitride quantum photonics.

The innovation of synthetic strategies for incorporating heterocycles into carborane is a significant objective in the realm of carborane chemistry on account of the fact that heterocyclic skeletons are widespread among natural products as well as bioactive molecules and the versatility applications of carboranes in medicinal chemistry and materials science. This method disclosed a facile and practical protocol for the synthesis of 1-benzothiazolyl-o-carboranes through an iodosobenzene-mediated intramolecular oxidative annulation process of C(1)-N-arylthioaacylamino-o-carborane. A series of 1-benzothiazolyl-o-carboranes have been synthesized in good to excellent yields. This work would be an important reference for the synthesis of aromatic heterocycle-carborane derivatives and promote their applications in designing drug candidates and functional materials.

Incision dressings play a crucial role in postoperative care, while hydrogel, as a commonly used polymeric material, can effectively maintain wound moisture and promote wound healing. The present study aims to fabricate a dual-functional hydrogel dressing, carboxymethyl chitosan hydrogel loaded with the nonsteroidal anti-inflammatory drug flurbiprofen (hCMPG-FP), for alleviating postoperative acute pain and promoting incision healing. hCMPG-FP exhibits excellent properties such as gelation, drug release, and degradation, and, in particular, possesses good incision conformability after secondary lyophilization. In vitro and in vivo experiments have confirmed that hCMPG-FP can exert dual functions of wound healing promotion and analgesia, which is associated with the antibacterial activity, coagulation-promoting effect, and cell migration-promoting ability of carboxymethyl chitosan hydrogel, as well as the analgesic and anti-inflammatory properties of flurbiprofen. In conclusion, when acting on incisions, hCMPG-FP regulates multiple pathways such as wound healing and inflammation modulation, exerts ideal dressing functions, and provides a theoretical basis and experimental evidence for the further development of innovative wound treatment strategies.

The structural information on protein-ligand complexes is crucial for small-molecule design and drug discovery. Yet primary resources often have heterogeneous annotations, lack machine-ready ligand categorization, and require substantial postprocessing before large-scale modeling. Here, we present LigandExplorer, an open-source, automated postprocessing pipeline that identifies and extracts covalent and noncovalent ligands from biomolecular complex structures and standardizes outputs for downstream use. Using residue-level graphs built solely from atomic coordinates, LigandExplorer is robust to missing or inconsistent metadata and integrates LightGBM models to classify ligands (peptides, nucleic acids, phospholipids, carbohydrates, organics, and ions) and assess interaction relevance. Because the pipeline is rerunnable, it can be applied to each new databases release to keep derived, categorized data sets current without altering source records. On the PDBbind v2020 refined set, LigandExplorer achieved a 98.38% raw structural agreement under harmonized comparison criteria prior to any manual reconciliation; the remaining discrepancies were analyzed separately and were dominated by divergences between raw RCSB entries and curated PDBBind records. On the PepBDB, LigandExplorer successfully processed 4881 of 5005 complexes, achieving a 97.52% success rate. Most failures reflected upstream record errors, where complex cyclic peptides constituted the primary algorithmic boundary. LigandExplorer thus mitigates data-cleaning burdens and enables rapidly refreshed, standardized data sets for computational modeling and molecular design.