Small Methods最新文献

Label-free characterization of nanoparticle surface functionalization at single-particle resolution is essential for a wide range of applications. Solid-state nanopore sensing provides a direct electrical readout that is intrinsically sensitive to the size, surface layer, and interfacial chemistry of single particles in liquid environments. The trapping-based nanopore sensing regime further enables probing surface-dependent particle-pore interactions with extended observation time. Here, a solid-state nanopore trap-based fingerprinting method is presented to differentiate single nanoparticles with distinct surface modifications. The method combines a "trap-release" measurement protocol with a multi-metric analysis workflow that extracts blockade distributions, sub-level statistics and frequency-domain signatures from trapping events, and constructs a unique fingerprint for each particle species. Applied to silica cores (≈25-30 nm) functionalized with APTES, NHS-PEG₄-Biotin and Tween-20, the approach generates distinct fingerprints that map to surface charge, coating conformation and configuration heterogeneity. Moreover, in situ detection of surface chemical transformation via specific streptavidin binding is demonstrated, with stoichiometry-dependent progression of the fingerprints. This platform provides a complementary tool to optical, spectral and ensemble assays for characterizing engineered nanoparticle surfaces and tracking interfacial molecular interactions in solution with label-free and single-particle sensitivity.

Cost-effective catalysts are pivotal in addressing energy and environmental challenges through the catalytic conversion of small molecules. Cyano-bridged metal frameworks (CMFs), as a subclass of reticular materials, demonstrate potential in small molecule conversion. However, CMFs are conventionally utilized as precursors for derivative synthesis, which inadvertently overshadows their intrinsic properties. Recent research has revealed that CMFs have emerged as direct catalysts. Accordingly, the feasibility is investigated of directly employing CMFs as catalysts for small molecule conversion and propose integrated design strategies encompassing element selection, structural modulation, and adaptation to working conditions. Specifically, insights is offered into the rational selection and combination of building units based on an updated understanding of CMFs' coordination environments. A crystallization-kinetics-guided, multi-dimensional assembly methodology is further proposed to achieve structural diversity and topological complexity. Finally, the application potential is demonstrated of CMFs in small molecule conversion through experimental evaluation and theoretical analysis of key intrinsic material properties. This study establishes a conceptual and methodological foundation for advancing CMFs toward broader applications in small molecule conversion.

Alloy-based anodes featuring high capacity and moderate operating potentials hold great promise for high-energy-density all-solid-state batteries (ASSBs). However, the significant volume fluctuations during cycling often lead to solid-solid interfacial failure, compromising reversibility and cycling stability. Multilevel architectural designs of composite alloy anodes have proven effective in enhancing electronic conductivity, ion transport, and interfacial stability. Herein, the influence of stacking sequence on the structural evolution and electrochemical performance of electrodes composed of silicon (Si) and aluminum (Al) is investigated. The results reveal that the plastic deformability of the upper layer active material (directly interfacing with the solid-state electrolyte) and its electrochemical potential window critically influence the reversibility, rate capability, and failure mechanism of the composite anode. Notably, when Si is employed as the upper layer, the anode delivers an initial Coulombic efficiency of 87.3% at 0.25 mA cm^-2, significantly exceeding that of the Al-upper configuration (59.3%). These results provide mechanistic understanding for the rational design of composite alloy anodes, highlighting the importance of component stacking for mitigating kinetic limitations and enhancing the performance of ASSBs.

Transition metals and their derivatives have demonstrated considerable potential in the field of electromagnetic wave absorption owing to their complementary dielectric and magnetic loss capabilities. However, achieving satisfactory impedance matching with pure transition metal-based materials remains challenging, which restricts the operational frequency bandwidth and limits the minimal thickness. Aerogels, with their unique 3D porous networks, high porosity, large surface area, and ultra-low density, offer an ideal supporting matrix for hosting transition metals and their derivatives. Such composite structures not only improve impedance matching but also introduce diverse attenuation mechanisms, thereby enabling superior electromagnetic wave absorption performance. This review begins with a systematic introduction to the fundamental mechanisms of electromagnetic wave absorption. It subsequently summarizes the design strategies for aerogel architectures from the perspective of gelation principles, categorizes various types of aerogel-based composites incorporated with transition metals and their derivatives, and highlights recent research advances in this emerging field. Finally, the current challenges and future prospects for the development of transition metal-based aerogel absorbers are outlined. This comprehensive overview is intended to illuminate the path for the rational design of next-generation, high-performance microwave absorbers with integrated multifunctionality.

The persistent contamination of aquatic ecosystems by recalcitrant tetracycline antibiotics demands advanced catalytic systems beyond conventional oxidation methods. Here, a sustainable high-entropy catalyst, FeMnCoZnCu@NCNP@CA is reported, comprising MOF-derived multi-metallic nanoparticles confined within a nitrogen-doped carbon matrix and anchored on a 3D cellulose aerogel scaffold. The hybrid is obtained by pyrolyzing a quinary FeMnCoZnCu-NTA MOF precursor. This hierarchical design integrates several key features: high-entropy stabilization to suppress phase segregation, N-doping-driven charge redistribution to enhance conductivity and active-site density and multivalent redox coupling to promote reactive oxygen species generation (SO₄•^-, •OH, ¹O₂) and accelerate electron transfer. The confined carbon matrix effectively minimizes metal leaching (<0.1 ppm), while the aerogel macroporosity ensures rapid diffusion and enables >85% catalyst recovery. Under optimal conditions ([Catalyst] = 0.25 g L^{- 1}, [PMS] = 0.31 g L^{- 1}, pH = 3), FeMnCoZnCu@NCNP@CA achieves >98% tetracycline degradation within 15 min, exhibiting a rate constant (k = 0.070 ± 0.013 min^{- 1}) that is 4.2 times higher than the mono-metallic Fe@NCNP and surpasses di-, tri- and tetra-metallic analogues. This work highlights MOF-derived high-entropy hybrids as a promising platform for antibiotic remediation through the synergistic integration of multi-metallic entropy, nitrogen doping, structural confinement and biomass aerogel engineering.

Artificial membrane systems have enabled powerful studies of lipid dynamics and bilayer mechanics, yet they lack the structural complexity of living cells, where membranes are embedded within an extracellular matrix (ECM). Here, a biomimetic platform is presented that integrates fibronectin (FN) and collagen type I (COL) onto the surface of giant unilamellar vesicles (GUVs) to investigate ECM-induced modulation of membrane properties. ECM coating imparts distinct, protein-specific effects on vesicle curvature, mechanical resilience, and lipid diffusivity. FN promotes vesicle budding and membrane softening, while COL induces rugged membrane topographies and mechanical stiffening. Furthermore, ECM proteins reshape the geometry and stability of phase-separated lipid domains, mimicking curvature heterogeneity observed in cell membranes. Strikingly, vesicle budding events observed in FN-coated GUVs resemble exosome-like release, suggesting that ECM identity not only dictates membrane mechanics but may also regulate vesicle biogenesis. This system captures essential mechanobiological interactions between the ECM and the plasma membrane in the absence of transmembrane linkers. The findings provide a tunable platform for studying ECM-membrane coupling and ECM-vesicle interplay with relevance to exosome modeling, offering new directions for engineering responsive synthetic cells and advancing extracellular vesicle biology.

The 2D nanofilm bulge test, which uses an Atomic Force Microscope (AFM) to measure the deflection of a suspended film under various conditions, has emerged as an important measurement platform for understanding mechanical, barrier, and permeability properties of 2D materials as thickness approaches the angstrom scale. The problem considered in this work is the limitation of such bulge analyses imposed by the AFM whereby dynamic measurements under high pressure, high temperature, and chemically corrosive conditions are limited. In this work, a technique is developed for measuring nanofilm deflection using only visible light interferometry. Both theoretical and semi-empirical models are applied to translate multicolor interference patterns from broadband excitation into estimates of nano-film deflection, allowing nanoscale precision in most cases. The technique and algorithm advanced in this work allows the use of widespread optical microscopy to widen the study of these important 2D nanofilm systems to more relevant conditions.

The functionalization of DNA origami with peptides is a powerful strategy for creating nanodevices for therapeutic and diagnostic applications. A critical but often overlooked challenge is the non-specific electrostatic binding of cationic peptides to the anionic DNA nanostructure, which leads to uncontrolled stoichiometry and undermines functional predictability. Here, the study systematically characterizes this issue and demonstrates a practical purification strategy to mitigate it. It is quantitatively shown that cationic peptides associate with DNA origami in vast excess of their intended binding sites, a phenomenon not observed with anionic control peptides. This non-specific binding is confirmed to be electrostatic and is effectively screened by high salt. To address this, a charge-dependent purification approach is evaluated using polyethylene glycol (PEG) precipitation, showing that cationic peptides require extensive purification (≥7 cycles), whereas anionic peptides need only minimal treatment (2 cycles) to achieve precise loading. Crucially, the study provides definitive functional evidence that a therapeutic peptide (brain-derived neurotrophic factor-mimicking peptide) must be attached via stable, site-specific hybridization to elicit a potent biological response; non-specifically adsorbed peptides are largely inactive. This work provides a set of critical design guidelines and purification considerations necessary for the rational design of reliable and functionally predictable DNA nanodevices.

Microscale patterning of delicate materials such as colloidal nanoparticle monolayers, solvent-swollen polymer substrates, and 3D resonators in millimeter/terahertz (mm/THz) dielectric metasurface remains a formidable challenge for conventional photolithography. Overcoming these limitations is critical for the next generation of wearable electronics, photonic devices, and metamaterials. Here, a versatile strategy using photocurable perfluoropolyether (PFPE) is introduced to create high-precision, reusable soft template guided by predesigned photomasks. These templates enable non-destructive, high-fidelity transfer of diverse functional materials including metal films, composites, and nanoparticle monolayer onto a wide range of substrates. Remarkably, the PFPE template can be reused multiple times without compromising patterning fidelity, offering a cost-effective solution for large-scale manufacturing. Beyond general microscale patterning, this approach provides unprecedented control over 3D dielectric resonators in mm/THz all-dielectric metasurfaces, delivering superior electromagnetic performance. With its combination of precision, reusability, and adaptability to various surfaces, this method opens exciting opportunities for microscale fabrications across flexible electronics, advanced photonics, and metasurfaces, redefining what is possible with soft-template patterning.

The Sb₂S₃ absorber has received tremendous attention in recent years for high-performance solar cells due to its excellent optoelectronic properties, especially for indoor photovoltaics that have gained significant interest as a sustainable solution for powering Internet of Things electronics. However, the Sb₂S₃ absorber suffers from its complicated defect characteristic, which is closely associated with the quasi-1D crystal structure. Herein, a chemical bath deposition (CBD) based precursor engineering strategy is developed to deposit high-quality Sb₂S₃ absorber films via pH regulation and nominal cation doping. The careful characterization of Sb₂S₃ films reveals that the manipulation of the chemical environment of CBD precursor solutions promotes the heterogeneous nucleation and growth of Sb₂S₃ films on the substrate, further resulting in the reduction in the grain boundary (GB) density. The reduced GB contributes to the decrease in defect density in Sb₂S₃ films. Benefitting from the suppressed nonradiative recombination and increased carrier concentration, the resultant planar Sb₂S₃ solar cells yield a competitive power conversion efficiency of 7.90%. Furthermore, a high-performance Sb₂S₃ solar minimodule with an active area of 16.25 cm² is first constructed using laser scribing. This work underscores the importance of the precursor engineering for solution-processed antimony chalcogenide solar cells.