Physics

Quasi-two-dimensional perovskites have emerged as promising candidates for high-quality blue-light emission in perovskite light-emitting diodes (PeLEDs). However, the efficiency of related devices is still limited by unbalanced crystallization in mixed-halide systems, where rapid nucleation at the interface creates defects that increase nonradiative losses, and the uncontrolled formation of low-dimensional phase disrupts energy funneling and exciton transfer. Herein, we introduce a salt-assisted interface engineering strategy that incorporates NH 4 NO 3, Na 2 SO 4, and KCl into the hole transport layer (HTL) to simultaneously regulate nucleation, crystal growth, and phase evolution. NH 4 +, Na +, and K + ions serve as interfacial nucleation sites that promote controlled, uniform crystallization, while the accompanying SO 4 2, NO 3 –, and Cl – anions coordinate with undercoordinated Pb 2+, suppressing defect formation and regulating the distribution of the quasi-2D phase. Pure-blue PeLEDs with the modified HTLs emit at 462, 463, and 469 nm, with maximum luminance values of 1035, 999, and 1087 cd/m 2 and EQEs of 9.09, 9.06, and 10.14%, respectively. Additionally, a transfer-enabled soft lithography approach was engineered to accomplish accurate and reproducible micropatterning of the perovskite emissive layer. Benefiting from this strategy, the HTL-modified micro-PeLEDs with a diameter and pitch of both 10 μm exhibit pure-blue emission with maximum luminance values of 546, 507, and 686 cd/m 2 and corresponding peak EQEs of 6.39, 6.30, and 6.80%, respectively.

Gold-nanoparticles-based lateral flow immunoassays (AuNPs-LFIAs) are widely used for point-of-care testing, yet their sensitivity remains fundamentally limited, likely because random antibody orientation on AuNP surfaces restricts Fab accessibility and antigen recognition efficiency. Precise control of antibody orientation is thus critical for maximizing probe activity, yet existing directional conjugation strategies are often multistep, technically complex, and poorly scalable. Here, we report an ultrafast biomimetic mineralization strategy that enables one-step, room-temperature self-assembly of zeolitic imidazolate framework-8 (ZIF-8) with antibodies and dual-ligand AuNPs, producing uniform hybrid nanoprobes within 5 min. ZIF-8 shell preserves the plasmonic properties of AuNPs while simultaneously enhancing colloidal stability and optical signal intensity. Molecular dynamics simulations suggest a two-step orientation model: (i) rapid electrostatic attraction between negatively charged Fc regions and Zn 2+ ions initiates nucleation, followed by (ii) Fc-associated interfacial interactions that promote preferential Fc-oriented binding and anisotropic Fc/Fab distribution, thereby enhancing Fab exposure for efficient antigen recognition. This controlled assembly increases Fab accessibility more than 3-fold relative to conventional adsorption or co-precipitation strategies, minimizes nonspecific adsorption, and amplifies signal output. When applied to competitive LFIAs, the oriented nanoprobes enabled ultrasensitive detection of chloramphenicol down to 13 pg/mL, corresponding to approximately 1 order of magnitude higher sensitivity than AuNPs-based LFIA gold standard. By integrating mechanistic insight with operational simplicity, this work establishes a generalizable platform for ultrafast, scalable, and antibody-orientation-controlled nanoprobe fabrication for next-generation LFIAs in food safety, clinical diagnostics, and environmental monitoring.

Sharp Raman bands near 1450 and 1530 cm –1 observed under 633 nm excitation have previously been attributed to localized vibrational modes of zigzag and armchair graphene edges. Here, we employ an isotope-resolved Raman spectroscopy approach to investigate the origin of these features. Monolayer 13 C graphene was synthesized and transferred alongside 12 C graphene reference samples, enabling a direct comparison of isotope-dependent Raman signatures under identical processing conditions. Despite clear isotope-induced shifts of the intrinsic graphene modes, the peaks near 1450 and 1530 cm –1 exhibit no isotope-dependent frequency shift, demonstrating that they do not originate from graphene lattice vibrations. Instead, their excitation-wavelength dependence and spectral characteristics are consistent with Raman enhancement of adsorbed molecular species under resonant conditions. These results establish isotope labeling as a robust experimental strategy for distinguishing intrinsic graphene vibrational modes from extrinsic Raman signals and provide a revised interpretation of Raman features previously attributed to graphene edge phonons.

Real-time, on-chip learning has become increasingly important as artificial intelligence edge-computing systems are deployed in dynamic environments ranging from autonomous vehicles to robotics, where static pretrained models are insufficient. In this context, analog in-memory computing hardware has been explored to alleviate energy and latency bottlenecks, but its limited reconfigurability has hindered the implementation of reinforcement learning in deployed artificial intelligence agents. Here, we demonstrate split-gate MoS 2 memtransistors where local field-effect gating of the Schottky contacts and semiconducting channel enables improved control of memristive switching ratios and conductance states, respectively. These characteristics enable efficient implementation of reinforcement learning due to the combination of nonvolatile synaptic weight updates and rapid parameter adjustments. Adaptive reinforcement learning performance is benchmarked with a cartpole balancing task that serves as an elementary robotic example for embodied decisions and actions, ultimately showing a 6-fold improvement in total reward and a 5-fold reduction in the number of programming steps.

Copper nanoclusters stand out as one of the most promising catalysts in the electrochemical nitrate reduction reaction (NITRR) for ammonia (NH 3 ) synthesis, owing to their well-defined structures and high metal utilization. Herein, we report an interface coordination nucleation strategy for the uniform growth of copper nanoclusters (Cu NCs) on hydrazone-linked covalent organic frameworks (HL-COF). The periodically arranged hydrazone bonds in COF structure ensure uniform growth of copper nanoclusters, fully exposing active sites in electrocatalysis. Theoretical calculations reveal that the abundant low-coordinate Cu atoms within the Cu nanoclusters on HL-COF significantly enhance the adsorption of *NO 3 intermediates. Moreover, these Cu nanoclusters effectively reduce the energy barrier for the rate-determining step (*NO→*NHO). The resulting 0.5-Cu NCs/HL-COF catalyst shows an impressive Faradaic efficiency (FE NH3 ) of 98.6% at −1.0 V vs RHE, even with a very low nitrate concentration (0.01 M NO 3 – ). In a flow cell test, it maintains an industrially applicable nitrate reduction current of 203.8 mA·cm –2 for a long duration. This study provides an interface coordination nucleation strategy that leverages the inherent periodic arranged active groups of COFs to controllably synthesize uniformly dispersed metal nanoclusters for various catalytic reactions.

High Resolution Image Download MS PowerPoint Slide Aromatic volatile organic compounds (VOCs) are toxic air pollutants that pose serious health risks even at trace concentrations. Their nonpolar character makes the design of efficient sorbents particularly challenging, as adsorption is governed mainly by weak dispersion forces. Here, we identify pore geometry as an effective structural descriptor for discovering metal–organic frameworks (MOFs) capable of efficient trace-level VOC capture. Screening a diverse set of MOFs revealed that one-dimensional channels with rhombic or square cross sections enhance host–guest interactions and promote strong affinity for aromatic molecules. Guided by this principle and sustainability-by-design criteria, we identify MIP-211(Al) (Materials from the Institute of Porous Materials of Paris) as a top performer with among the highest toluene uptake of 4.7 mmol g –1 at 0.0008 P / P 0 (31 ppm). This material combines excellent cycling stability, facile regeneration under vacuum, and scalable green synthesis. Synchrotron powder X-ray diffraction (SPXRD) and density functional theory (DFT) calculations confirm that rhombic pore geometry governs strong toluene affinity at trace amounts. Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy showed that MIP-211(Al) retains 60% of its performance up to 15% relative humidity. Applying pore geometry as a descriptor in a secondary screening identified a candidate with a toluene uptake of 3.6 mmol g –1 at 0.0008 P / P 0 (31 ppm) at dry conditions, with potential applicability up to 70% relative humidity. This study demonstrates the importance of pore geometry as a nanoscale parameter for efficient trace aromatic VOC adsorption.

Acute radiation-induced lung injury is a serious and potentially life-threatening complication of radiotherapy for thoracic malignancies or accidental radiation exposure, characterized by high incidence, limited treatment options, and substantial mortality. To address the lack of effective therapies for preventing and treating radiation-induced lung injury, we developed an engineered nanoplatform, BAT-exo@Au, generated by functionalizing exosomes derived from young brown adipose tissue (BAT) with 1,2-distearoyl- sn -glycero-3-phosphoethanolamine–polyethylene glycol–thiol (DSPE-PEG-SH) and gold nanoparticles via chloroauric acid (HAuCl 4 ) incubation. Our results show that BAT-exo@Au was efficiently internalized by irradiated lung tissue and exerted radioprotective effects by suppressing reactive oxygen species production and attenuating radiation-induced inflammatory responses. In addition, BAT-exo@Au mitigated radiation-induced epithelial–mesenchymal transition while enhancing tumor radiosensitivity, suggesting a dual therapeutic advantage. Mechanistically, BAT-exo@Au reduced apoptosis and preserved mitochondrial membrane potential after radiation in vitro. Transcriptomic analysis identified G protein-coupled receptor 183 ( Gpr183 ) as a potential downstream target, showing upregulation after radiation but downregulation following BAT-exo@Au treatment. Further in vitro experiments demonstrated that BAT-exo@Au promoted the interaction between Gpr183 and the E3 ubiquitin ligase NEDD4, facilitating Gpr183 ubiquitination and proteasomal degradation. This study suggests that exosomes derived from young BAT may serve as a therapeutic strategy for the prevention of radiation-induced lung injury. In conclusion, BAT-exo@Au shows promise as a preventive approach for radiation-induced lung injury, potentially through modulation of Gpr183 via enhanced Gpr183–NEDD4 interaction and ubiquitination.

Oral squamous cell carcinoma (OSCC) is one of the most common cancers in the head and neck. Immunotherapy has emerged as a promising treatment option for metastatic OSCC because of its potential clinical benefits; however, its effectiveness is limited by the immunosuppressive tumor microenvironment (TME), short-lived responses, and poor infiltration. To overcome these issues, we developed a strategy that combines photothermal therapy (PTT) with chimeric antigen receptor (CAR)-T cell immunotherapy. The prepared conjugated polymer nanoparticles (CPNPs) serve as efficient near-infrared-II (NIR-II) photothermal agents, enabling localized PTT and triggering strong immunogenic cell death (ICD) to activate T cells. Moreover, we engineered a lymph node-targeting nanosystem (ApoA1@PNPs) to improve in vivo production of CAR-T cells. Mucin 1 (MUC1)-specific CAR-T cells were designed to enhance tumor antigen recognition. This combined approach helps CAR-T cells reach primary tumor sites more effectively and induces long-lasting systemic immunity. By addressing the main limitations of traditional CAR-T therapy in OSCC, our integrated PTT/CAR-T strategy offers a potential therapeutic approach with significant clinical potential. This dual method aims to improve patient outcomes by achieving better tumor control.

Developing candidate materials with specific recognition and efficient adsorption is highly valuable for both the environment and ecology. Covalent organic frameworks (COFs) are an ideal multifunctional candidate material due to their structure, functional modification, and excellent physical and chemical properties. However, most COF monomers can coordinate with various metal ions, thus limiting their application in accurate identification. Herein, we designed a double-bridged porphyrin-based covalent organic framework (Tp-PDA-COF) by introducing double-bridging monomers to orderly connect the 5,10,15,20-tetra(4-aminophenyl)porphyrin (TAPP) center to construct the 2D tetragonal topological structure with an excellent fluorescence property. The designed topology effectively reduces spatial hindrance, and the specific electron cloud density can optimize metal ligand orbitals, achieving effective capture and specific coordination recognition, which achieves sensitive detection of Cu 2+ through obvious fluorescence chromaticity change with a detection limit of 40.76 nM. Furthermore, incorporating poly(vinyl alcohol) polymer into the COF increases interlayer spacing and suppresses π–π stacking, forming a fluorescent Tp-PDA-COF aerogel. Owing to the selective coordination of Cu 2+ and the synergistic adsorption of gel structure, Tp-PDA-COF aerogel has an ultrahigh adsorption capacity for Cu 2+ (1902 mg/g). This work provides a structural design strategy for regulating functional COFs with specific recognition and adsorption capabilities.

High Resolution Image Download MS PowerPoint Slide Color centers hosted in hexagonal boron nitride (hBN) have emerged as a highly promising platform for single-photon emission and spin-photon technologies relevant to quantum communication and quantum networking. As a wide bandgap van der Waals material, hBN can host optically active quantum defects across a broad spectral range. Here, we demonstrate a simple and scalable oxygen-plasma process that reproducibly creates single quantum emitters in hBN with blinking-free zero-phonon lines (ZPLs) spanning near-infrared (NIR) from 700 up to 971 nm. These emitters combine MHz-level brightness, single-photon purity up to 99.9%, and ultranarrow cryogenic line widths down to 2.7 GHz under quasi-resonant excitation, placing them in a particularly attractive regime for quantum photonics. Photostability measurements further reveal resistance to photobleaching, subnanometer spectral stability over long time scales, and near-shot-noise-limited intensity fluctuations. Analysis of the phonon sidebands shows weak vibronic coupling and ZPL-dominated emission, with Debye–Waller factors approaching 50%. Control experiments together with elemental mapping support oxygen incorporation as a necessary ingredient in activating the NIR emitter population, while first-principles calculations identify O N V N and O N V N H as the leading defect candidates. These results establish a high-performance NIR quantum-emitter platform in hBN for free-space quantum networking and future integrated quantum-photonic architectures.

Two-dimensional (2D) MoO 2 nanoflakes offer metallic conductivity and multiband structure, but their controlled growth remains limited by coupled precursor transport and reduction chemistry. Here we establish a programmable chemical vapor deposition approach with precisely timed H 2 introduction, decoupling precursor transport from surface reduction. This temporal gating yields thickness-controlled (5–30 nm), highly crystalline single-crystal MoO 2 nanoflakes. Time-resolved optical microscopy, X-ray diffraction, and Raman spectroscopy reveal a stepwise MoO 3 to MoO 2 pathway involving Mo 4 O 11 -like intermediates. Adjusting the H 2 /Ar ratio controls nucleation density, lateral size, and thickness. The same timing principle also guides the 2D growth of WO 2 and Cr 2 O 3 . Temperature-dependent Hall measurements show nonlinear Hall behavior and, in thinner flakes, sign reversal of the Hall coefficient, providing direct evidence for bipolar transport with thickness-dependent electron–hole balance. This temporal gating approach provides a general strategy for nonlayered oxide growth and advances understanding of multicarrier transport in MoO 2 .

Single-atom catalysts have demonstrated great potential in addressing dual-electrode challenges in Li–S batteries, while the role of substrate curvature remains elusive. Herein, we report the regulation of electronic properties of Co single-atomic catalysts by modulating the curvature of carbon nanotube supports, thereby accomplishing distinct yet complementary optimization in both the cathode and anode. At the cathode, the curved single-atom catalyst manages to enhance polysulfide capture and accelerate sulfur redox kinetics; over the Li anode, it promotes uniform Li deposition by facilitating Li + transport and regulating nucleation behavior. Consequently, reciprocal optimization of both electrodes enables the Li–S full cell to deliver a discharge capacity of 1122.2 mAh g –1 at 0.2 C. This work reveals distinct roles of curvature-modulated single-atomic mediators at the S cathode and Li anode, offering insights into the development of Li–S batteries.

Sodium metal anodes are plagued by uncontrolled dendrite growth and electrolyte depletion due to sluggish interfacial ion transport and nonuniform nucleation. Scaffold materials that combine sodiophilic sites with fast lateral diffusion pathways can potentially resolve both issues, yet integrating these two functions into a single architecture remains challenging. Herein, we develop a vacuum pyrolysis strategy to fabricate a hollow CoSb/C scaffold that, upon electrochemical activation, produces sodiophilic Co nanoparticles and a Na 3 Sb superionic conductor, effectively suppressing local aggregation and enhancing kinetic reversibility. Cryogenic transmission electron microscopy (Cryo-TEM) observations reveal that the resulting bifunctional interface facilitates the formation of a thin, amorphous, and mechanically robust solid electrolyte interphase (SEI), which remains stable and suppresses electrolyte degradation throughout prolonged cycling. The scaffold delivers a Coulombic efficiency of 99.7% and stable cycling over 1200 h, and Na 3 V 2 (PO 4 ) 3 -based full cells retain 84% capacity after 1000 cycles at 5 C.

Hemoglobin has recently gained attention as a potential building block for amyloid-based biomaterials. However, the lack of atomic-level structural information has hindered its rational engineering. Here, we present atomic structures of hemoglobin amyloid fibrils determined by cryo-electron microscopy (cryo-EM). The structure of a new polymorph (PM2), together with the previously reported PM1, reveals that hemoglobin fibrillization is driven by the β-subunit. Using virtual fitting and molecular dynamics simulations, we demonstrate that the homologous α-subunit cannot adopt the amyloid fold due to steric clashes and electrostatic incompatibilities under acidic conditions (pH 2.0), particularly the introduction of positively charged histidine residues within the amyloid core. In contrast, the β-subunit forms stable fibrils, as its sequence enables favorable hydrophobic packing and electrostatic compatibility. Our findings thus provide the atomic-level explanation for subunit-specific amyloid formation in hemoglobin and establish a structural foundation for designing nanomaterials from this widely available agricultural byproduct.

Group IV materials, such as Si and Ge, are widely used in quantum information devices due to their CMOS compatibility and excellent transport properties. However, their indirect band gaps hinder optical spin control such as initialization or readout via photons. In this work, we establish a pathway toward optically addressable group IV quantum dots, realizing them in SiGe with a hexagonal crystal structure. This material benefits from a direct band gap with wavelength emission that is tunable through the Ge content. The hexagonal SiGe quantum dots are realized here as axial heterostructures within branched nanowires, enabling precise geometric control and a high crystal quality. Nanometer-sharp heterointerfaces are achieved without defect formation, indicating a fully elastic relaxation of the lattice mismatch. Geometric phase analysis and computational simulations validate this behavior. These results show the feasibility of hexagonal SiGe quantum dots, providing a promising platform for integrating optical control into group IV quantum architectures.

DNA nanotechnology has advanced beyond sequence design toward precise control of local substructures, such as single-stranded gaps and branched motifs, whose configuration governs mechanical stability and function. However, quantitative interrogation of these dynamic elements at the single-molecule level under native solution conditions remains challenging. Here, we present a quasi-static nanopore scanning strategy that enables deterministic electrical imaging of DNA substructures. Using surface-tethered dual-gap DNA scaffolds, we demonstrate that ionic blockade amplitudes from unstructured single-stranded branches scale with high linearity (R 2 = 0.998) over nearly an order of magnitude in length (10–81 nt), achieving 5-nucleotide resolution. In contrast, base-paired architectures (hairpins and aptamers) exhibit pronounced nonlinear amplification. This work establishes nanopore scanning as a quantitative electrical imaging modality for simultaneous readout of branch length and topology, providing a foundation for quality control, structural validation, and real-time monitoring of complex DNA nanodevices.

High Resolution Image Download MS PowerPoint Slide GaAs-based nanowires hosting active quantum heterostructures provide a promising route toward monolithic integration of single-photon sources on silicon, a key requirement for scalable quantum photonics. However, ultrathin axial quantum-emitter formation is often hindered by facet-dependent growth dynamics and rotational twins, which induce lateral overgrowth and compromise interface abruptness. Here, we develop InGaAs-based quantum emitters by tailoring facet evolution via dilute Sb incorporation, which efficiently suppresses twins and promotes confined axial insertion at the growth-front facet. This approach significantly enhances the probability of obtaining abrupt, few-nanometer-thin quantum dots at the nanowire tip. Single-nanowire optical spectroscopy reveals intense, spatially localized emission from the active region with lifetimes as short as (0.51 ± 0.02) ns, and second-order photon-correlation measurements consistently exhibit pronounced antibunching with g (2) (0) < 0.4, confirming single-photon emission. These results establish a strong correlation between twin density and axial heterostructure formation, identifying defect control as a key factor in realizing monolithically integrated nanowire single-photon sources.

Two-dimensional (2D) chiral perovskites offer a promising magnetic-field-free framework for spin-selective light–matter interactions. Yet, the influence of organic cations on Rashba-related spin effect has not been well comprehended. In this work, we demonstrate that the alloying of achiral and chiral spacers provides an efficient approach to modulating spin-selective phenomena in 2D chiral perovskites. Mixed-spacer films with achiral n -butylammonium spacers in a chiral methylbenzylammonium lattice exhibit enhanced chiroptical activity and spin-dependent optical responses compared the films with achiral or chiral organic cations. Based on the density functional theory and femtosecond circularly polarized transient absorption measurements, it is unveiled that spacer alloying perturbs the local structural environment and modifies Rashba-related band-edge asymmetry, resulting in a larger spin-selective transient response asymmetry and an enhanced optical Stark effect. It is elaborated that achiral–chiral spacer alloying can regulate Rashba-related spin-selective phenomena in 2D chiral perovskites and lead to coherent spin-optoelectronic functioning.

Spatially periodic modulations of the superconducting gap have been recently reported in diverse materials and are often attributed to the exotic superconducting state of Cooper-pair density waves (PDWs). An alternative mechanism, termed pair-breaking scattering interference (PBSI), was proposed to produce gap modulations without invoking PDWs. Here, we search for signatures of PBSI in bulk FeSe, which hosts no PDWs, using scanning tunneling microscopy with superconductive tips, enabling enhanced energy resolution and Josephson tunneling. Subsurface magnetic scatterers with Yu-Shiba-Rusinov states and reduced Josephson current are identified in FeSe, around which we observe particle-hole symmetric gap modulations. Those modulations have wavevectors consistent with intrapocket PBSI. We further demonstrate that phase-referenced quasiparticle interference imaging offers an independent and direct probe of PBSI beyond gap mapping. These results establish that gap modulations commonly attributed to PDWs can arise from PBSI, motivating further investigation of the intriguing gap modulation phenomenology.

The geometric phase, such as the Pancharatnam-Berry (PB) phase, is widely employed in metasurfaces for broad functionalities. Conventional studies dominantly rely on the linear dependence of the PB phase on the orientation angle of the meta-atoms. Although some previous studies indicate the breakdown of such a linear dependence, its underlying mechanisms remain largely unknown. In this study, we provide a detailed analysis of the evolution of PB phases, unveiling the nonnegligible role of coupling among adjacent meta-atoms. From the perspective of quasi-normal modes (QNMs), we demonstrate that the PB phase is solely related to the far-field radiation polarizations of the QNMs excited, decided by both meta-atom orientations and their mutual coupling. We experimentally demonstrate these effects using a meticulously designed grating, aligning closely with our theoretical predictions. This study establishes a systematic framework for rigorous PB phase analysis, broadening the horizon for the high-precision characterization of meta-optical devices.