Nano Letters最新文献

Antibiotic resistance in bacteria poses a global health challenge, underscoring the need for strategies that restore the effectiveness of existing drugs. Here, we demonstrate that amphiphilic Janus nanoparticles (NPs), with separate polycationic and hydrophobic hemispheres, act as effective antibiotic adjuvants that synergistically enhance the activity of conventional antibiotics. Unlike uniformly cationic NPs, Janus NPs exhibited strong synergy with multiple antibiotics against Acinetobacter baumannii, including the multidrug-resistant clinical isolate A. baumannii A42-2. Embedding Janus NPs in agar gel provided a stable platform that reproducibly increased antibiotic susceptibility in various Gram-negative bacteria, including A. baumannii and highly motile species such as Escherichia coli. These findings demonstrate that amphiphilic Janus NPs can synergistically boost antibiotic activity and that embedding them in gels yields a stable platform for assessing their performance and potentially deploying them in future biomedical applications.

Silicon monoxide (SiO) anode offers high theoretical capacity but suffers from poor intrinsic conductivity, sluggish interfacial kinetics, and unstable electrode–electrolyte interphase. Heterogeneous coating can partially alleviate these issues, yet interfacial resistance between coating layers still limits fast-charging performance. Herein, we design a dual-coated SiO anode featuring a high-work-function N-doped carbon layer and a low-work-function TiN layer to create a built-in electric field (BEF) at the heterointerface. This BEF promotes directional Li⁺ transport, substantially lowering interfacial resistance and accelerating ion diffusion kinetics. Consequently, the developed TiN-SiO/C anode achieves exceptional rate performance (758 mA h g^–1 at 5 A g^–1) and long-term cycling stability (694.5 mA h g^–1 after 800 cycles at 2 A g^–1). Moreover, the BEF fosters an inorganic-rich SEI (LiF/Li_xTiN) with reduced Li⁺ migration energy (37.74 kJ mol^–1), improving interfacial mechanical integrity and electrochemical stability. This work highlights work-function-engineered heterointerfaces as a powerful strategy toward high-performance battery materials.

Smart contact lenses (SCLs) have advanced from refractive aids to multifunctional platforms, yet integrating passive (e.g., electromagnetic interference (EMI) shielding) and active (e.g., electroretinogram (ERG)) functionalities remains unexplored. Here, we report dual-mode contact lenses (DMCLs) fabricated by sequential spray-coating of silver nanowires (AgNWs)/MXene on commercial lenses. The AgNWs endow DMCLs with EMI shielding effectiveness (SE) > 20 dB, while MXene stabilizes the conductive network, maintaining performance after 1 month immersion in care solution. Biocompatible coatings ensure safe 8 h wear without irritation. In vivo rabbit experiments validate DMCLs’ ability to record six standard ERG waveforms, with signal fidelity preserved over 1 week. By unifying EMI protection (passive) and ERG monitoring (active) in one platform, DMCLs establish a new paradigm for multifunctional ocular devices in SCL-driven healthcare.

Spin-dependent anisotropic Fermi surfaces in altermagnets can give rise to nonrelativistic spin–charge conversion, known as the altermagnetic spin splitting effect (ASSE). While several studies have reported the inverse ASSE (IASSE) in altermagnetic RuO₂ thin films, its magnitude and sign relative to the spin Hall effect (SHE) remain controversial. Here, we demonstrate reversible IASSE in RuO₂ thin films by controlling the Néel vector orientation and accounting for the anisotropic transport characteristic. Spin Seebeck measurements in CoFeB/RuO₂ heterostructures reveal polarity reversal of the IASSE-induced spin charge conversion (SCC) upon Néel vector switching. This indicates that IASSE can either enhance or suppress SCC depending on the Néel orientation. These results provide compelling evidence for the symmetry-governed and directionally reversible nature of IASSE in RuO₂.

Measuring the atomic-scale surface structure of KTaO₃ (KTO) is important and challenging due to its broken translational symmetry. Here, we employed integrated differential phase contrast imaging to resolve the KTO surface at atomic resolution. Through precise measurements of lattice constants, bond lengths, atomic displacements, and strain gradients, we determined the polarization characteristics at the subunit-cell level. Our results reveal a significant increase in lattice constants and strain gradients within the top ∼4 unit cells as the out-of-plane polarization enhances. Electron energy loss spectroscopy further uncovered the electronic origins of surface reconstruction, showing pronounced distortions of the Ta–O octahedra. In combination with density functional theory calculations, we demonstrate that these effects arise from surface-driven orbital reconstruction and Ta–O hybridization. This work offers insights into subunit-cell surface polarization and is expected to provide guidance for surface engineering in functional applications.

Highly filled thin composite elastomers are crucial for thermomechanical applications in electronics packaging and engineered interfaces. However, most current research focuses on bulk-like materials and performance optimization. This work is the first to investigate the thickness-dependent macroscopic properties of such composites, establishing a distinction between film-like and bulk-like behaviors based on specific properties. Using polydimethylsiloxane-based composite elastomers containing 90 wt % aluminum as a model, we identify two critical thicknesses (200 and 800 μm). Above 800 μm, the material exhibits bulk-like behavior, with mechanical and viscoelastic properties becoming thickness-independent. Below 800 μm, these properties show a pronounced thickness dependence. In contrast, the out-of-plane thermal conductivity exhibits enhancement only below 200 μm, which can be attributed to the anisotropic characteristics of the polymer-mediated hierarchical filler networks. This regime exhibits film-like characteristics, with thermomechanical properties diverging from bulk-like behavior. These findings bridge the gap between basic research and practical applications in thickness-constrained packaging applications.

The stacking order in two-dimensional (2D) materials reveals a hidden quantum degree of freedom, turning multilayers into platforms for ferroelectricity, magnetism, correlated flat bands, and superconductivity─properties largely apart from monolayer counterparts. This stacking-enabled electronic/magnetic diversity defines stackingtronics, where the interlayer registry operates as a programmable knob for modulating quantum matter and reaching next-generation nanodevices. This review covers stacking-order-induced functionalities, multiphysics coupling, and effective strategies for their manipulations. In situ real-space techniques, capable of resolving multiple states and interlayer sliding dynamics, are highlighted for uncovering the microstructural origin of sliding ferroelectric polarization. Finally, we briefly discuss the key challenges in the synthesis, property optimization, structural dynamics and artificial-intelligence-induced growth-structure–property design frameworks that hold promise for the full potential of stackingtronics in 2D materials.