Nanoscale Horizons最新文献

Boron can become unintentionally incorporated into transition metals during the reduction of metal salts with borohydride. The presence of boron at the surfaces of transition metals (TMs) such as Pd and Pt is known to significantly influence their catalytic properties. In this study, we employ density functional (DFT) calculations to investigate the thermodynamics and kinetics of boron incorporation into ∼1.5 nm particles and extended (111) surfaces of fcc-Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, and Al. Our results reveal that boron exhibits high thermodynamic stability in interstitial subsurface sites on (111) surfaces and nanoparticles of Rh, Pt, and Pd. Unlike extended surfaces, metal nanoparticles (NPs) can also stabilize boron within the coordination environment of surface metal atoms, with such sites being particularly stable in Rh, Ir, and Ni nanoparticles. Furthermore, the energy barriers for B migration at NP edge sites from the surface to subsurface decrease to <0.5 eV (for all metals except Ir), and the migration barrier for boron incorporation into the in-surface sites is lower than 0.2 eV. Notably, B incorporation induces a shift in the d-band center of adjacent metal atoms, which indicates its pronounced impact on the catalytic activity of transition metals.

Biomolecular condensates formed via liquid–liquid phase separation (LLPS) are essential to cellular organization, catalysis, and regulation of biochemical pathways. Inspired by such natural systems, we present a new adaptive coacervate formed by multivalent salt-bridge interactions of polyhexamethylene biguanide (PHMB) polymer and adenosine triphosphate (ATP). These phase separated compartments efficiently sequester guanine-rich DNA sequences that adopt G-quadruplex (GQ) conformations in the presence of potassium ions. Hemin intercalates into these GQ structures to produce a catalytically active DNAzyme with amplified peroxidase-like activity. Within the coacervate, reduced molecular diffusion and increased local substrate concentrations synergistically augment the catalytic efficiency of the DNAzyme by 10-fold compared to that in the unconfined state. Integrating an enzymatic degradation cycle by alkaline phosphatase allows ATP-fueled dissipative behavior of the coacervates. By integrating self-assembling catalytic motifs within a dissipative host environment, this system demonstrates key principles of spatially and temporally regulated catalysis, mimicking features of cellular microreactors. Our work highlights the potential of synthetic LLPS-based platforms as tunable and compartmentalized catalytic systems, with implications for biomimetic reactor design and the development of advanced functional materials.

Entropy-driven drying-mediated self-assembly of plasmonic nanocrystals (termed “plasmonic atoms”) has emerged as a general strategy for fabricating plasmene nanosheets from a wide range of monodisperse nanocrystals. However, extending this approach to binary systems remains challenging due to the complex nanoscale interactions between dissimilar nanocrystal shapes. Here, we introduce a combined enthalpy- and entropy-driven strategy to achieve an orderly mixed two-dimensional (2D) binary nanoassemblies from complementary reacting polymer-ligated nanocrystals. Using nanocubes and nanospheres as model systems, “plasmonic molecules” were first synthesized via enthalpy interactions of different nanocrystals through stoichiometric reactions between complementary grafting polymers. This was followed by an entropy-driven, slow-drying-mediated assembly of “plasmonic molecules”. This led to well-controlled binary plasmenes without phase separation. This method could be extended to a diverse range of other building block shapes and size scales. Our methodology indicates a new pathway for 2D nanocrystal assemblies with well-controlled mixing at nanoscale precision.

Ulcerative colitis has no cure and there are limited options for patients. Many current therapeutic drugs have poor bioavailability and targeting ability, including inhibitors of the cGAS–STING pathway, which has limited their clinical approval for colitis. Here we address this critical need through inflammation-triggered nanomicelles (ITMs) that are composed of biopolymer hyaluronic acid which specifically targets the inflamed colon by binding to CD44 receptors. ITMs encapsulate the cGAS inhibitor RU.521 improving the drug's overall bioavailability, and utilize a reactive oxygen species (ROS)-responsive thioketal linker, enabling site-specific drug release at the inflamed colon. The efficacy of ITMs was shown in a clinically relevant microbial-induced colitis model that recapitulates human colitis. Acute colitis was developed in gnotobiotic altered Schaedler's flora (ASF) IL-10 knockout mice infected with Helicobacter bilis or Escherichia coli 1D to induce severe and moderate colitis, respectively. Oral delivery of ITMs alone significantly reduced inflammation in the E. coli 1D model, while combining ITMs with anti-IL-12p40 antibodies mitigated disease severity in the H. bilis model as revealed by body weight recovery, reduced colon shortening, restoration of the intestinal epithelium, and reduction in proinflammatory cytokines. In vivo end points were validated with ex vivo tissue imaging and assays that identified the downregulation of cGAS expression and other mechanisms by which ITMs enable mucosal healing. These findings highlight the potential of ITMs for targeted, site-specific drug delivery as a novel IBD treatment strategy, and the importance of inhibiting the cGAS–STING pathway in inflammatory diseases.

DNA self-assembly is a highly programmable method to construct arbitrary architectures based on sequence complementarity. Among various constructs, DNA crystals are macroscopic crystalline materials formed by assembling motifs via sticky end association. Due to their high structural integrity and size ranging from tens to hundreds of micrometers, DNA crystals offer unique opportunities to study the structural properties and deformation behaviors of DNA assemblies. For example, enzymatic ligation of sticky ends can selectively seal nicks resulting in more robust structures with enhanced mechanical properties. However, the research efforts have been mostly on experiments involving different motif designs, structural optimization, or new synthesis methods, while their mechanics are not yet fully understood. The complex properties of DNA crystals are difficult to study via experiments alone, and numerical simulation can complement and aid the experiments. The coarse-grained molecular dynamics (MD) simulation is a powerful tool that can probe the mechanics of DNA assemblies. Here, we investigate DNA crystals made of four different motif lengths with various ligation patterns (full ligation, major directions, connectors, and in-plane) using oxDNA, an open-source, coarse-grained MD platform. We found that several distinct deformation stages emerge in response to mechanical loading and that the number and the location of ligated nucleotides can significantly modulate structural behaviors. These findings should be useful for predicting crystal properties and thus improving the design.

Porous silicon (PSi)-based biosensors are promising platforms for label-free biomarker detection in complex environments, including potential in vivo applications, but their use remains limited due to their susceptibility to biofouling caused by their high surface area. Here, we address this challenge by covalently immobilizing zwitterionic peptides with glutamic acid (E) and lysine (K) repeating motifs onto PSi thin films. Systematic screening identified a specific sequence, EKEKEKEKEKGGC, which exhibited superior antibiofouling properties compared to conventional polyethylene glycol (PEG) coatings. This peptide effectively prevented nonspecific adsorption of biomolecules from complex biofluids, including gastrointestinal (GI) fluid and bacterial lysate. Applying this strategy to a PSi-based aptasensor for lactoferrin detection, we achieved more than one order of magnitude improvement in both the limit of detection and (LOD) and signal to noise ratio over PEG-passivated sensors, enabling sensitive detection in clinically relevant concentration ranges. The peptide's antibiofouling performance was also extended to biofilm-forming bacteria and adherent mammalian cells, underscoring its broad-spectrum protection against both molecular and cellular contamination. This universal strategy enhances the reliability of PSi biosensors by addressing a key cause of sensor failure in real-world applications.

The single-molecule dynamics of π-conjugated organic molecules on surfaces is fundamental for applications ranging from catalysis to molecular electronics. Adsorption and diffusion, in particular of organic aromatics, are typically driven by van der Waals forces, energy dissipation in terms of friction, and quantum effects, making them ideal for probing surface energy landscapes. However, their fast motion at thermal equilibrium poses experimental challenges. Recent advances have provided unprecedented insights into the diffusion mechanisms of several organic molecules on metallic and graphitic surfaces. These studies reveal a spectrum of motion, from ballistic transport to Brownian diffusion, influenced by surface symmetry, molecular size, charge transfer, and molecular degrees of freedom. Notably, friction at 2D material interfaces can be exceptionally low, leading to superlubricity – a phenomenon which highlights the role of atomic-scale interactions in determining energy dissipation and molecular mobility. We review experimental and computational techniques capturing diffusion at atomic length scales, highlighting how density functional theory and molecular dynamics complement experimental findings. Despite recent advances, key questions remain, such as how friction varies across different surfaces and how external factors affect mobility. Understanding these interactions is essential for controlling molecular assembly and surface functionalisation: controlling diffusion and dissipation at the nanoscale may enable self-assembled nanostructures, where controlled molecular motion drives highly ordered surface architectures. Finally, beyond technological applications, surface diffusion is also critical in astrochemistry, where it influences the formation of complex organic molecules.

All-solid-state supercapacitors (ASSCs) are critical for next-generation flexible and wearable electronic devices, but their development has been hindered by the challenge of balancing high energy storage performance with mechanical flexibility in wearable energy storage systems. MXene materials offer excellent electrical conductivity, large surface area, and outstanding charge storage capability, but their application in flexible devices is limited by poor mechanical stability and structural degradation. To overcome these challenges, we have developed MXene/cellulose nanofiber (CNF) composites. CNF is a cheap and environmentally friendly material with a huge storage capacity on earth. The doping of CNFs into a layered MXene material prevents the stacking of the MXene, improves the ionic transport speed, maintains the excellent electrochemical properties of the MXene, and enhances the structural reinforcement and flexibility. The flexible, binder-free ASSCs have excellent electrochemical properties with a volumetric capacitance of 94.21 F cm⁻³. The electrochemical properties also showed no degradation in bending tests in the range of 30°–120°. The capacitance retention was 97.87% after 10 000 bending cycles at an angle of 60°. This work provides a scalable and green approach to fabricating high-performance MSCs and points the way to the next generation of wearable electronics.

Extracellular vesicles (EVs) have emerged as valuable sources for liquid biopsy in disease diagnostics, given their protein and nucleic acid cargoes (e.g., miRNA, mRNA, glycoRNA) can serve as critical biomarkers. DNA nanotechnology, leveraging its inherent programmability, high specificity, and powerful signal amplification capability, offers a transformative approach for the bioanalysis of EVs. This review summarizes recent advances in DNA nanotechnology-based analytical methodologies for detecting EV-associated proteins and nucleic acids. We detail the underlying principles, applications, and performance of key strategies, including aptamer-based recognition, enzyme-free catalytic amplification circuits (e.g., HCR, CHA), enzyme catalytic amplification techniques (e.g., RCA, CRISPR-Cas systems), and DNA nanostructures-assisted amplification. The integration of these DNA tools into multiplexed detection platforms is also discussed. Finally, current challenges and future perspectives concerning clinical translation of EV detection are presented.

MEMS and NEMS increasingly integrate multiple functions within compact platforms, enabled by piezoelectric and ferroelectric materials such as PZT, BaTiO₃, AlN, ScAlN, PVDF, and Hf_0.5Zr_0.5O₂. These materials support devices including mechanical sensors, RF resonators for gas detection, energy harvesters, non-volatile memories such as FeRAM and FeFETs, and neuromorphic computing arrays, as well as microspeakers and microphones for compact audio interfaces. They also play a key role in reconfigurable photonic components through acousto-optic and electro-optic modulation. This review examines materials, device designs, and integration strategies shaping next-generation intelligent microsystems across domains such as Artificial Intelligence of Things (AIoT), wearables, and robotics.