Abstract Stacked van der Waals heterostructures based on transition-metal dichalcogenides (TMDs) exhibit a rich variety of exotic interfacial phenomena. Substituting one component with an organic semiconductor (OSC) enables the design of hybrid heterostructures with tunable functionalities for optoelectronic, photovoltaic, and spintronic applications. In this work, exploiting scanning tunneling spectroscopy (STS), photoemission orbital tomography (POT), and G0W0 electronic structure calculations, we experimentally and theoretically demonstrate the self-assembly of an ordered single layer of pentacene (5A) above monolayer WS2, exhibiting a type-II (staggered) band alignment in the hybrid 5A/WS2 interface. Central to this result is the synthesis of extended, atomically flat WS2 ─ an essential prerequisite for a highly ordered and electronically homogeneous OSC/TMD interface ─ which can only be reliably achieved via bottom-up growth, most notably molecular beam epitaxy (MBE). We realize this by leveraging Au(111) as an atomically clean and conductive sample for epitaxial growth ─ a necessary requirement for reliable and comparable STS/POT characterizations. The high quality of the synthesized heterostructure, together with its type-II band alignment, establishes pentacene/WS2 as a model system for orbital-resolved studies of charge transfer, energy-level renormalization, and nonequilibrium interfacial processes in hybrid organic/inorganic 2D heterostructures.
Photodetectors capable of switching between photovoltaic (PV) and photomultiplication (PM) modes are highly desirable for adaptive sensing and optical communication, but integrating high sensitivity with high speed remains a fundamental challenge. Here, we overcome this trade-off by demonstrating a bias-switchable perovskite photodetector (PD) based on a quasi-two-dimensional perovskite via interfacial deep-trap engineering. By tailoring interfacial trap states at the perovskite interface, trap-enabled barrier narrowing and facilitated hole injection are activated at low bias, producing high gain without sacrificing speed. The optimized device operates in self-powered PV mode at 0 V, delivering a detectivity (D*) of 1.12 × 1011 Jones and fast rise/fall times (τr/τf) of 2.10/1.21 μs. Under an ultralow reverse bias of -0.3 V, it achieves a record-high external quantum efficiency exceeding 2100%, a D* of ∼1.7 × 1012 Jones, and μs-level τr/τf in PM mode. Compared with state-of-the-art dual-mode PDs, our approach achieves the lowest bias and μs-level response simultaneously. This bias-switchable perovskite PD integrated with PV and PM dual-mode capability eliminates the need for external amplification circuits and provides rapid detection, highlighting significant potential for applications in portable sensing and dynamic optical environments.
Abstract Accurate staging of inflammatory bowel disease (IBD) using magnetic resonance enterography (MRE) remains challenging because of limited precision. Although microvascular remodeling is a pivotal driver of IBD progression, its contribution to imaging-based activity assessment remains insufficiently characterized owing to the rapid extravasation and short intravascular residence of current contrast agents. Here, an ultralow-dose MRE strategy is developed using a long-circulating (half-life ≈ 5 h), high-relaxivity (r1 = 40.89 mM–1 s–1 at 3.0 T) ultrasensitive nanoprobe to enable direct visualization and quantitative characterization of intestinal microvascular remodeling in vivo. In a rat colitis model, this approach reveals dynamic microvascular alterations during inflammatory progression and generates enhancement patterns that reflect both vascular retention and permeability-associated changes. Quantitative analysis of vascular imaging features enabled the development of a microvascular feature index (MFI), which was significantly associated with histopathological inflammatory activity. Integration of MFI with conventional MR metrics improved disease activity stratification by distinguishing low-activity lesions from moderate-to-severe inflammatory activity. This work establishes inflammation-associated vascular remodeling as an imaging-accessible biological process and demonstrates that contrast kinetics engineering can enable its quantitative characterization as an imaging biomarker. The resulting microvascular-centered framework complements conventional MRE and provides a biologically informed approach for inflammatory activity assessment in IBD.
Abstract Accurate optical gain measurement at the microscale has long been plagued by photorefractive effects that distort optical spectroscopy signals under high excitation conditions. Here, we develop a phase-sensitive microscopic transient white-light interferometry that disentangles gain dynamics from transient refractive index changes, enabling direct access to intrinsic gain in photorefractive materials. Applying this method to CsPbBr3 single-crystal microplatelets, we reveal that conventional measurements underestimate gain by up to 20%. The corrected gain exhibits a duration of 500 ps and a bandwidth of ∼30 nm. We further uncover that the optical confinement factor governs a nonmonotonic thickness dependence of gain, peaking at ∼140 nm. Exploiting this optimal cavity length in a DBR structure yields a lasing threshold of 0.07 μJ·cm–2. This work presents a general method for measuring gain in photorefractive micronano materials and offers design guidelines for high-performance microlasers and integrated photonic circuits.
Abstract Rheumatoid arthritis (RA) is a chronic autoimmune disease marked by persistent synovial inflammation, cartilage erosion, and systemic manifestations, including cognitive and neuropsychiatric complications. Increasing evidence highlights the bidirectional interplay of the joint-brain axis between peripheral inflammation and central nervous system dysfunction as a critical contributor to RA pathogenesis. Current frontline treatments, such as methotrexate (M), face challenges, including poor bioavailability, off-target toxicity, and limited efficacy in addressing neuroinflammation. To address these limitations, we developed methotrexate-loaded tryptophan-Poly(lactic-co-glycolic acid)-glutathione nanomicelles (M-WPG NMs), an advanced enzyme- and pH-responsive drug delivery platform designed for targeted release at inflamed joints. In collagen-induced arthritis (CIA) models, M-WPG NMs demonstrated superior therapeutic efficacy by significantly reducing joint inflammation, downregulating pro-inflammatory cytokines, and preserving joint architecture. Additionally, M-WPG NMs attenuated microglial activation and mitigated associated neuroinflammation in chronic RA, offering dual modulation of both peripheral and central inflammatory responses. This multifunctional nanocarrier improves methotrexate delivery, enhances therapeutic outcomes, and addresses the often-overlooked neurological components of RA. Our findings support the application of M-WPG NMs as a next-generation nanomedicine for comprehensive RA management, capable of controlling disease progression while offering protection against RA-induced cognitive dysfunction.
Abstract Brucellosis, a major global zoonosis causing over 2.1 million human infections annually, poses a significant threat to public health and livestock economies. Conventional vaccines face substantial limitations, including residual virulence and diagnostic interference in live attenuated vaccines, and poor immunogenicity in subunit vaccines. To address these issues, we developed BP26-OMP16Es, a self-assembling nanoparticle vaccine constructed by fusing immunodominant B- and T-cell epitopes from OMP16 to the self-assembling antigen BP26 via flexible linkers, yielding single-copy (1×) and double-copy (2×) epitope tandem nanoparticles. These particles formed homogeneous, barrel-shaped structures (14–23 nm) with strong immunoreactivity against Brucella-specific antibodies. In murine models, the vaccine elicited potent humoral and cellular immune responses, characterized by high antibody titers, enhanced IFN-γ+ CD8+ T cell proliferation, a balanced Th1/Th2 profile, and the induction of immunological memory for durable protection. Immune sera also mediated effective clearance of infected macrophages via antibody-dependent cellular cytotoxicity (ADCC). Challenge experiments confirmed that the vaccine significantly reduced splenic Brucella burden and alleviated pathological damage, with the 2× construct offering superior protection. In summary, this study integrates self-assembling nanotechnology with a multiepitope strategy to create a safe and potent vaccine platform. The 2× design enhances epitope density, boosting immunogenicity and conferring solid protection against Brucella infection. This approach provides valuable insights for developing vaccines against brucellosis and other intracellular pathogens.
Abstract Energy funneling holds strong promise for highly efficient energy conversion and light-emitting devices. Owing to their unmatched structural diversity, lead halide perovskites constitute an ideal platform to explore energy funneling phenomena and applications, a prominent example among which is the mixed-phase, quasi-2D perovskites. Here we report energy funneling between distinct exciton states within nominally phase-pure 2D perovskites, which is induced by lattice distortion that can be quantitatively controlled through organic cations. The existence of two excitonic states with distinct energies is manifested as correlated dual absorption and emission features from room temperature down to 4 K, which is further confirmed by magnetic circular dichroism spectroscopy. Transient absorption measurements reveal sub-picosecond energy funneling from the high-energy exciton to the low-energy exciton, which is also pump power dependent due to the state filling effect. These observations are highly reminiscent of but differ fundamentally from the inter-phase energy funneling in quasi-2D perovskites. Our study opens an additional avenue of controlling energy/charge flow in metal halide perovskites through structural engineering.
Abstract Oxidation-induced material failure severely threatens the service life of metallic materials spanning from industrial engineering components to nanoscale catalysts. In particular, the sudden structural collapse during early oxidation is highly destructive, however, its underlying atomic-scale mechanisms remain elusive. Herein, we directly captured the real-time dynamic evolution of this degradation using in situ atomic-resolution transmission electron microscopy. The structural degradation proceeds through an initial reversible oscillation followed by a rapid collapse. During the oscillatory stage, the reversible detachment and recapture of the outermost Ag atoms create transient surface vacancies that facilitate the incorporation of oxygen into the subsurface. Localized lattice expansion induced by subsurface oxygen lowers the lateral diffusion barrier, shifting the transport mechanism from vertical penetration to lateral diffusion. Ultimately, subsurface oxygen accumulation weakens interfacial metallic bonds, precipitating abrupt surface exfoliation. This study proposes the atomic-scale mechanism of how oxygen infiltrates the metal subsurface to trigger catastrophic failure, demonstrating a direct relationship between atomic-scale strain and macroscopic structural degradation during metal oxidation.
Abstract Vitreous floaters affect >80% of people over 60, severely impairing quality of life, yet no safe and effective treatment exists. Nd/YAG laser vitreolysis requires dangerously high fluences, risking retinal injury, and fails to address the underlying pathological cascade. Here, we report a laser-triggered cluster nanobomb (PDN-C) for ultralow-fluence vitreolysis and homeostasis restoration. The nanobomb comprises a magnetic iron-oxide core and targeting-peptide-linked bullets. It actively penetrates the viscous vitreous and anchors to pathological collagen aggregates. Upon pulsed-laser irradiation at a fluence ∼1000-fold lower than clinical Nd/YAG therapy, the core converts the laser into localized microbubble cavitation that ejects the bullets and ablates >87% of collagen mass without retinal phototoxicity. Mechanistically, the ejected bullets achieve a dual-biochemical blockade of the pathogenic ROS-MMP axis: doxycycline inhibits MMP-driven type IV collagen degradation, while the ultrananozyme scavenges ROS, delaying vitreous liquefaction. By coupling precision photomechanical ablation with dynamic microenvironment remodeling, this nanobomb offers a highly effective and safe translational paradigm for vitreous floaters, addressing both the symptoms and the underlying disease pathology.
Abstract Plasmonic nanostructures enable surface-enhanced Raman scattering (SERS) through nanoscale hotspots, where electromagnetic fields are strongly confined. Both hotspot intensity and density are critical for enhancing SERS, yet their individual contributions to SERS performance have not been directly compared within a structurally consistent system. Herein, we present four plasmonic nanostructures comprising a cubic nanoframe (CNF) with an identical outer geometry but a distinct internal architecture: hollow, tetrahedron-embedded, porous, or tetrahedron-embedded/porous to control hotspot intensity and density. Through single-particle and ensemble SERS measurements, we demonstrate that the tetrahedral solid core governs hotspot intensity while the porous domain controls hotspot density. Furthermore, hotspot intensity predominates SERS signal intensity at high analyte (2-naphthalenethiol) concentrations (10–4 to 10–8 M), whereas hotspot density becomes the critical determinant at low analyte concentrations (under 10–8 M). By preserving both characteristics, the tetrahedron-embedded porous CNF enabled superior peak resolution at high concentrations and reliable detection down to 10–15 M. This work demonstrates a reliable structure–property framework for the rational design of plasmonic-sensing platforms with simultaneously optimized signal intensity and detection sensitivity.
Abstract The anthrax protective antigen forms a heptameric transmembrane channel under acidic conditions and serves as a biological nanopore. Its use in nanopore sensing is limited by stability and signal quality under conventional electrolytes containing potassium or sodium ions. A stable anthrax protective antigen nanopore was constructed using a pH-asymmetric organic ionic liquid electrolyte, operated under a proton-driven gating mechanism. The resulting nanopore was evaluated for electrochemical performance, chemical stability, and capacity to distinguish levorotatory and dextrorotatory amino acid enantiomers. The system operated without the need for enzymes, chemical reactions, or machine-learning algorithms. The anthrax nanopore exhibited a single-channel open current of–approximately 5 pA, whereas commonly used protein nanopores display current amplitudes of tens to hundreds of picoamperes. This architecture provides a basis for chiral molecule identification via direct nanopore current readout.
The bulk spin photovoltaic (BSPV) effect can generate pure spin currents under illumination, but a general symmetry rule connecting pure spin photocurrent tensors across multiple sliding ferroelectric states remains lacking. Here, we establish a symmetry-programming principle for BSPV responses in sliding ferroelectric altermagnets. By combining first-principles calculations with spin space symmetry analysis, we show that interlayer sliding maps the allowed nonlinear spin photocurrent tensors between symmetry-related ferroelectric configurations. Bilayer MnPS3 realizes a six-state triangular-lattice example with direct reversal and C3-related reorientation, whereas bilayer Fe2MoS4 provides a four-configuration square-lattice prototype governed by a C2-type connection rule. In the target transport channels, the magnetic-sublattice-connecting symmetry allows the spin photocurrent while forcing the corresponding charge photocurrent to vanish, thereby producing a pure spin photocurrent. The SOC-included calculations preserve this symmetry-enforced spin-charge decoupling and the sliding-state switching relations. These results establish a symmetry-based framework for ferroelectric tuning of optospintronic responses.
RNA vaccines have become a transformative technology in infectious disease prevention and cancer treatment, thanks to their rapid development, high immunogenicity, and scalability in production. However, the clinical application of RNA vaccines faces significant challenges, including the inherent instability and susceptibility to degradation of naked RNA, its poor permeability across cell membranes, and the potential for nonspecific immune responses following systemic administration. Nanodelivery systems are key to addressing these challenges; by providing physical protection, enabling targeted delivery, promoting cellular uptake, and facilitating escape from endosomes, they significantly enhance the efficacy and safety of RNA vaccines. This review provides a comprehensive overview of the latest advances in nanodelivery systems for RNA vaccines, focusing on the characteristics of three distinct types of RNA vaccines─linear mRNA, self-amplifying RNA, and circular RNA─as well as the applications of lipid nanoparticles, polymeric nanoparticles, virus-like particles, and other emerging nanocarriers in enhancing RNA stability, boosting immunogenicity, and enabling precise targeting. Furthermore, this study will examine the key challenges in this field, including vector biosafety, large-scale production, cost-effectiveness, and storage and transportation, and will also outline future research directions and prospects for clinical translation.
Lithium-ion sieve (LIS) hydrogels offer a solution to powder loss and poor site accessibility of LIS in lithium extraction through swelling. However, their adsorption efficiency is constrained by the inherently slow diffusion of lithium ions (Li+) through tortuous pathways within the hydrogel matrix. Herein, we regulate Li+ transport channels in LIS hydrogels by engineering dynamic adsorption networks through swelling enhancement with anionic surfactants. By integrating pulsed-field gradient nuclear magnetic resonance (PFG-NMR) diffusion experiments with molecular dynamics simulations, we demonstrate that rapid swelling creates low-tortuosity percolation channels, which significantly accelerate Li+ diffusion and enhance active-site accessibility during adsorption. So, the LIS hydrogel achieves a Li+ adsorption capacity of 52.79 mg g-1 HMO, approaching the theoretical capacity, with a high adsorption rate constant of 5.85 mg mg-1 h-1. The LIS hydrogel retains over 80% of its capacity after 20 cycles while reducing Mn2+ dissolution loss. In natural Bohai seawater, it shows high Li+ selectivity and delivers a Li+ adsorption capacity of 12.45 mg g-1 HMO in a 15-day scaled-up extraction test. The accelerated swelling by anionic surfactant micelles also enhances photothermal lithium extraction efficiency by modulating water states. This work provides a general and robust strategy for designing high-efficiency adsorbents for the reversible extraction of strategic metals from natural seawater.
Abstract Two-dimensional (2D) semiconductors, with their atomically thin geometry and excellent electrostatic control, are promising channel materials for ferroelectric field-effect transistors (FeFETs). However, integrating high-quality ferroelectric gate stacks onto these ultrathin channels in a manner compatible with modern semiconductor manufacturing, particularly under back-end-of-line (BEOL) constraints, remains a major challenge primarily due to interfacial instability. Here, we demonstrate interface-engineered top-gated 2D FeFETs based on monolayer molybdenum disulfide (MoS2) integrated with ferroelectric hafnium–zirconium oxide (HZO) via atomic layer deposition. An ultrathin high-κ yttrium oxide (Y2O3) interfacial layer serves as both a nucleation and protection layer, enabling conformal HZO growth while preserving a sharp van der Waals interface. All fabrication steps were conducted below 300 °C, fully satisfying BEOL thermal budgets. The resulting devices exhibit intrinsic polarization-driven switching rather than trap-dominant behavior. Notably, they achieve a nearly ideal memory window of 3.6 V, corresponding to ∼90% of the theoretical maximum, under a low operating voltage of ±3.5 V, along with distinguishable nonvolatile switching characteristics. These results establish a CMOS and BEOL-compatible interface engineering strategy for integrating high-performance 2D FeFETs, providing a scalable pathway toward monolithic 3D systems for future embedded memory and logic-in-memory applications.
Abstract Atopic dermatitis (AD) is a chronic inflammatory skin disorder in which keratinocyte (KC)-derived thymic stromal lymphopoietin (TSLP) orchestrates pathogenic crosstalk between epithelial cells and immune cells. Here, we present a boron-doped copper single-atom nanomaterial (Cu/NC-B) designed to achieve a dual functional blockade of the TSLP signaling axis, offering a more comprehensive therapeutic intervention. Therapeutically, Cu/NC-B significantly alleviated MC903-induced AD-like lesions, showing efficacy comparable to that of crisaborole (CB) with a superior safety profile. Single-cell transcriptomics analysis revealed that Cu/NC-B selectively targets a previously uncharacterized, highly inflammatory KC subpopulation (KC_Spinous_Tslp), thereby disrupting a critical cellular node in AD pathology. At the molecular level, Cu/NC-B exerts its effects through two complementary pathways: epigenetic repression of TSLP via nicotinamide adenine dinucleotide (NAD+)-dependent activation of SIRT1/3 and competitive antagonism of the TSLP receptor (TSLPR). Our work establishes Cu/NC-B as a dual-action nanotherapeutic capable of concurrently suppressing TSLP transcription and disrupting its receptor engagement, thereby proposing a targeted intervention for AD treatment.
Abstract Nanozymes, which mimic the catalytic activities of natural enzymes, have been investigated as therapeutic agents for treating reactive oxygen species (ROS)-related diseases. Despite progress having been made in nanozyme engineering, their diverse nanostructures and poor atom utilization efficiency severely limit further applications. Symmetric Fe–N4 coordination in iron-based single-atom nanozymes (SANs) confers intrinsic ROS scavenging activity; however, excessive adsorption of oxygen intermediates restricts catalytic turnover. Here, we describe a spin-state engineering strategy to address this limitation through asymmetric coordination design. Phosphorus incorporation transforms the symmetric Fe–N4 motif into an Fe–PN3 configuration, inducing a transition of Fe 3d orbitals from a low-spin to a high-spin state. Density functional theory calculations indicate that this spin modulation raises the count of unpaired electrons and moves the d-band center nearer the Fermi level, which in turn tunes the binding energies of oxygen intermediates and speeds up the catalytic cycle. Consequently, the Fe–PN3 nanozyme exhibits substantially enhanced ROS detoxification efficiency compared with its Fe–N4 counterpart. In a glucocorticoid-induced osteonecrosis model, the spin-engineered nanozyme modulates the pathological redox microenvironment, restores impaired autophagic flux, and preserves tissue integrity. Single-cell RNA sequencing further indicates coordinated modulation of oxidative stress-responsive and autophagy-related pathways. Collectively, this work supports asymmetric coordination-induced spin-state regulation as a strategy for designing high-performance iron-based single-atom nanozymes with translational potential in ROS-driven degenerative diseases.
Abstract Cross-point memory arrays offer the minimum 4F2 cell footprint for high-density storage and in-memory computing, but their scalability is fundamentally limited by sneak-path currents unless each memory element is paired with a two-terminal selector that combines ultralow leakage, high drive current, steep turn-on, low operating voltage, high endurance, and thermal stability. Here, a van der Waals (vdW) step-barrier tunneling selector platform is reported, in which semiconductor–insulator–semiconductor energetics are engineered through transition-metal dichalcogenide/h-BN heterostructures and contact selection. Across four heterojunction variants, the platform delivers nonlinearity exceeding 107, OFF-state current densities down to ∼10–9 μA/μm2, ON-state current densities approaching 1 μA/μm2, and low operating voltages, together with weakly temperature-dependent ON-state transport from 80 to 300 K. Accelerated testing at 125 °C verifies endurance of at least 1011 cycles. Monolithic integration with resistive random-access memory yields a uniform 5 × 7 1S1R array, while circuit-level simulations show that 1S1R crossbars maintain a 94.8% read margin and >90% write margin even at the 256 × 256 scale, where selector-free arrays nearly fail. These results demonstrate the effectiveness of vdW step barriers as a selector platform for dense and energy-efficient cross-memory arrays.
Abstract Biological transmembrane molecular machines such as ATP synthase and flagellar motors couple chemical gradients to rotary motion and are essential to life. These biological pumps utilize energy and information ratchet mechanisms to overcome Brownian motion and directionally transport solutes across membranes. By contrast, fluid flow can be attained at the macroscopic level by continuous rotary motion. Here we explore the limits of rotary pump miniaturization by investigating the possibility of constructing a nanoscale Archimedes screw pump from a rapidly rotating DNA helix within a nanopore. Atomistic molecular dynamics simulations revealed that MHz rotational frequencies would be needed to surpass Brownian motion. Net water and ion translocation was driven in the same direction, irrespective of the charge on the DNA or nanopore, which was consistent with a nanoscale screw-pump mechanism. The efficiency of transduction of mechanical rotational input to the direction mechanical transport of water and ions was <0.00001%. Species flux followed the order water ≫ K+ > Na+ > Cl– ≫ Mg2+ ≈ Ca2+. The transport selectivity between cations and anions generated ionic currents (<100 pA). Altering the charges on the DNA, nanopore, and electrolyte modulated ion selectivity, and even reversed the generated streaming current in some scenarios. These simulations underscore the requirement for ratchet-based mechanisms in molecular machines operating at low velocities, while also providing insights that might be exploited in the design of advanced nanofluidic devices for ion separation or energy transduction.
Abstract Photocatalytic hydrogen peroxide (H2O2) generation represents a green pathway to produce H2O2, but currently its application is significantly limited by the low accumulated H2O2 concentration. Due to the metastable nature of H2O2, an ideal photocatalyst should possess excellent optoelectronic properties for fast H2O2 generation and a suitable surface to prevent H2O2 decomposition by photogenerated charge carriers. In this work, we have developed an efficient photocatalyst based on nitrogen-rich carbon nitride (C3N5). Potassium ion (K+) was applied to modify the electronic structure and surface properties of C3N5 to improve its H2O2 accumulation concentration. It shows that K+ can lower exciton binding energy and extend the lifetime of photogenerated charge carriers. A more stable *OOH intermediate is formed on KC3N5, with the O2 adsorption configuration changed from the Yeager type to the Pauling type on KC3N5. As a result, KC3N5 shows a selectivity of 97.2% for H2O2 generation pathway, achieving a H2O2 production rate of 44.2 mmol h–1 g–1 with an apparent quantum yield (AQY) of 89.3% at 420 nm. More impressively, after 16 h of continuous reaction, the H2O2 concentration reaches 656.8 mM (2.2 wt %), a concentration close to medical-use requirements. The findings provide a strategy for practical photocatalytic H2O2 production by regulating both excitonic properties and O2 adsorption behavior in photocatalysts.
