Distinct Nanoscale Research Articles

Electrochemical synthesis of NiCo layered double hydroxides on nickel-coated graphite for water splitting: understanding the electrochemical experimental parameters.

The electrochemical synthesis of nickel-cobalt (Ni-Co) layered double hydroxides (LDHs) on a nickel-coated graphite support for water splitting applications was investigated. Three different electrochemical approaches, namely, cyclic voltammetry (CV), chronoamperometry (CA), and chronopotentiometry (CP), were employed for evaluating the electrodeposition of Ni-Co LDHs. The graphite support was initially coated with a thin layer of Ni by applying 50 mA cm-2 constant current density for 120 s. Raman spectroscopy results confirmed the intercalation of nitrates, evidenced by the characteristic Raman bands at 1033 cm-1 (ν 1) and 1329 cm-1 (ν 3). These characteristic bands were indicative of nitrate intercalation, a key feature of LDHs, further supporting the classification of the synthesized material as NiCo LDHs on a nickel-coated graphite support. It was observed that the electrochemical routes used for the synthesis influenced the morphology, composition, and electrochemical behavior of the obtained Ni-Co LDHs. Moreover, atomic force microscopy (AFM) measurements revealed distinct nanoscale surface characteristics associated with the synthesis methods, with the Ni-Co LDH synthesized via the CV route exhibiting higher surface heterogeneity than that synthesized via the constant potential method (CA), resulting in a more textured surface. These findings were further supported by roughness average (Ra) values, where CV-synthesized Ni-Co LDH displayed the highest R a of 221 nm, indicating a more extensive active surface area. The electrochemical performance, both for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), were correlated with these surface variations. This study provides valuable insights into the electrochemical experimental parameters for the synthesis of Ni-Co LDHs and their potential application in water splitting processes.

Bayesian metamodeling of early T-cell antigen receptor signaling accounts for its nanoscale activation patterns.

T cells respond swiftly, specifically, sensitively, and robustly to cognate antigens presented on the surface of antigen presenting cells. Existing microscopic models capture various aspects of early T-cell antigen receptor (TCR) signaling at the molecular level. However, none of these models account for the totality of the data, impeding our understanding of early T-cell activation. Here, we study early TCR signaling using Bayesian metamodeling, an approach for systematically integrating multiple partial models into a metamodel of a complex system. We inform the partial models using multiple published super-resolution microscopy datasets. Collectively, these datasets describe the spatiotemporal organization, activity, interactions, and dynamics of TCR, CD45 and Lck signaling molecules in the early-forming immune synapse, and the concurrent membrane alterations. The resulting metamodel accounts for a distinct nanoscale dynamic pattern that could not be accounted for by any of the partial models on their own: a ring of phosphorylated TCR molecules, enriched at the periphery of early T cell contacts and confined by a proximal ring of CD45 molecules. The metamodel suggests this pattern results from limited activity range for the Lck molecules, acting as signaling messengers between kinetically-segregated TCR and CD45 molecules. We assessed the potential effect of Lck activity range on TCR phosphorylation and robust T cell activation for various pMHC:TCR association strengths, in the specific setting of an initial contact. We also inspected the impact of localized Lck inhibition via Csk recruitment to pTCRs, and that of splicing isoforms of CD45 on kinetic segregation. Due to the inherent scalability and adaptability of integrating independent partial models via Bayesian metamodeling, this approach can elucidate additional aspects of cell signaling and decision making.

Revealing nanoscale structure and interfaces of protein and polymer condensates via cryo-electron microscopy.

Liquid-liquid phase separation (LLPS) is a ubiquitous demixing phenomenon observed in various molecular solutions, including in polymer and protein solutions. Demixing of solutions results in condensed, phase separated droplets which exhibit a range of liquid-like properties driven by transient intermolecular interactions. Understanding the organization within these condensates is crucial for deciphering their material properties and functions. This study explores the distinct nanoscale networks and interfaces in the condensate samples using a modified cryo-electron microscopy (cryo-EM) method. The method involves initiating condensate formation on electron microscopy grids to limit droplet growth as large droplet sizes are not ideal for cryo-EM imaging. The versatility of this method is demonstrated by imaging three different classes of condensates. We further investigate the condensate structures using cryo-electron tomography which provides 3D reconstructions, uncovering porous internal structures, unique core-shell morphologies, and inhomogeneities within the nanoscale organization of protein condensates. Comparison with dry-state transmission electron microscopy emphasizes the importance of preserving the hydrated structure of condensates for accurate structural analysis. We correlate the internal structure of protein condensates with their amino acid sequences and material properties by performing viscosity measurements that support that more viscous condensates exhibit denser internal assemblies. Our findings contribute to a comprehensive understanding of nanoscale condensate structure and its material properties. Our approach here provides a versatile tool for exploring various phase-separated systems and their nanoscale structures for future studies.

Synthesis methods and applications of mesoporous and microporous materials

Over the past decades, the academic community has devoted considerable attention to mesoporous and microporous materials, primarily due to their distinctive nanoscale pore structures. Despite the extensive research conducted on these materials, there is still a pressing need to develop methods for optimizing their synthesis and improving their performance. Therefore, this paper introduces the basic concepts of mesoporous and microporous materials and their importance, and describes in detail their typical synthesis methods that include the solution-gel method for the synthesis of mesoporous materials and the ionothermal synthesis method for the synthesis of microporous materials. The paper then goes on to examine some of the more common characterization methods that are used in the field, such as X-ray diffraction (XRD), nitrogen adsorption, and transmission electron microscopy (TEM), and also lists some of the ways in which these characterization methods have been used in the context of electrochemical capacitors and photocatalytic explanation. It has been shown that mesoporous and microporous materials have the potential for significant applications in energy storage and environmental remediation. Further research should concentrate on the improvement of the synthesis process and the investigation of additional application areas, with the aim of fully exploiting the potential of these materials.

Unified Understanding of the Structure, Thermodynamics, and Diffusion of Single-Chain Nanoparticle Fluids.

Single-chain nanoparticles (SCNPs) are a fascinating class of soft nano-objects with promising properties and relevance to protein condensates, polymer nanocomposites, nanomedicine, bioimaging, catalysis, and drug delivery. We combine molecular dynamics simulations and equilibrium and time-dependent statistical mechanical theory to construct a unified understanding of how the internal conformational structure of SCNPs, of both a simple fractal globule-like form and more complex objects with multiple internal intermediate length scales, determines nm-scale intermolecular packing correlations, thermodynamic properties, and center-of-mass diffusion over a wide range of concentrations up to dense melts. The intermolecular pair correlations generically exhibit a distinctive deep correlation hole form due to SCNP internal connectivity structure and repulsive interparticle interactions associated with a globular-like conformation on the macromolecular scale, with concentration-dependent deviations at small separations. Unanticipated exponential-like dependences of the equation-of-state, osmotic compressibility, and center-of-mass diffusion constant on SCNP macromolecular packing fraction are theoretically predicted and confirmed via simulations. System-specific behaviors are found associated with SCNP internal structure, but overarching regularities are identified and understood based on a generalized effective globule conformation on macromolecular scales. Diffusivity slows down by 2-3 decades with increasing concentration and is understood as a consequence of a nonactivated excluded volume-driven weak-caging process associated with space-time correlated intermolecular forces experienced by the SCNP. Good agreement between the theory and simulations is established, testable predictions are made, and a quantitative comparison with viscosity measurements on a specific SCNP fluid is carried out. The basic theoretical approach can potentially be extended to treat the chemical and physical consequences of varying the structure of other classes of soft nanoparticles with distinctive internal nanoscale organization relevant in nanotechnology and nanomedicine, and the possible emergence of macromolecular kinetically arrested glasses.

Effect of Size and Morphology of Different ZnO Nanostructures on the Performance of Dye-Sensitized Solar Cells

In this study, the influence of zinc oxide (ZnO) nanostructures with various morphologies on the performance of dye-sensitized solar cells (DSSCs) was investigated. Photo-electrodes were fabricated incorporating ZnO transport layers of distinct nanoscale morphologies—namely nanoparticles, microballs, spiky microballs, belts, and triangles—and their respective current–voltage characteristics were evaluated. It was observed that the DSSCs employing the triangular ZnO nanostructures, with a side length of approximately 30 nm, achieved the highest power conversion efficiency of 2.62%. This was closely followed by the DSSCs using spherical nanoparticles with an average diameter of approximately 20 nm, yielding an efficiency of 2.54%. In contrast, the efficiencies of DSSCs with microball and spiky microball ZnO nanostructures were significantly lower, measuring 0.31 and 1.79%, respectively. The reduction in efficiency for the microball-based DSSCs is attributed to the formation of micro-cracks within the thin film during the fabrication process. All DSSC configurations maintained a uniform active area of 4 mm². Remarkably, the highest fill factor of 59.88% was recorded for DSSCs utilizing the triangular ZnO morphology, with the spherical nanoparticles attaining a marginally lower fill factor of 59.38%. This investigation corroborates the hypothesis that reduced particle size in the transport layer correlates with enhanced DSSC performance, which is further amplified when the nanoparticles possess pointed geometries that induce strong electric fields due to elevated charge concentrations.

Super-resolution GSDIM microscopy unveils distinct nanoscale characteristics of DNA repair foci under diverse genotoxic stress

DNA double-strand breaks initiate the DNA damage response (DDR), leading to the accumulation of repair proteins at break sites and the formation of the-so-called foci. Various microscopy methods, such as wide-field, confocal, electron, and super-resolution microscopy, have been used to study these structures. However, the impact of different DNA-damaging agents on their (nano)structure remains unclear. Utilising GSDIM super-resolution microscopy, here we investigated the distribution of fluorescently tagged DDR proteins (53BP1, RNF168, MDC1) and γH2AX in U2OS cells treated with γ-irradiation, etoposide, cisplatin, or hydroxyurea. Our results revealed that both foci structure and their nanoscale ultrastructure, including foci size, nanocluster characteristics, fluorophore density and localisation, can be significantly altered by different inducing agents, even ones with similar mechanisms. Furthermore, distinct behaviours of DDR proteins were observed under the same treatment. These findings have implications for cancer treatment strategies involving these agents and provide insights into the nanoscale organisation of the DDR.

Nanoconfinement of ultra-small Bi2Te3 nanocrystals on reduced graphene oxide: a pathway to high-performance sodium-ion battery anodes.

Bismuth telluride (Bi2Te3) nanomaterials have attracted considerable attention owing to their intriguing physicochemical properties and wide-ranging potential applications arising from their distinctive layered structure and nanoscale size effects. However, synthesizing sub-100 nm ultra-small Bi2Te3 nanocrystals remains a formidable challenge. To date, there has been little investigation on the performance of these ultra-small Bi2Te3 nanocrystals in sodium-ion batteries (SIBs). This study presents a general strategy for synthesizing ultra-small Bi2Te3 nanocrystals on reduced graphene oxide (Bi2Te3/rGO) through a nanoconfinement approach. First-principles calculations and electrochemical kinetic studies confirm that the ultra-small Bi2Te3/rGO composite material can effectively mitigate volumetric expansion, preserve electrode integrity, and enhance electron transfer, Na-ion adsorption, and diffusion capacity. As a result, the Bi2Te3/rGO electrode demonstrates a remarkable initial specific capacity of 521 mA h g-1 at 0.1 A g-1, showcasing outstanding rate behaviour and long-lasting cycle life exceeding 800 cycles at 1 A g-1 while preserving exceptional rate properties. The function of the battery is indicated by ex situ TEM and XPS findings, which propose a conventional dual mechanism involving conversion and alloying. This work paves the way for rapid advancements in Bi2Te3-based SIB anodes while contributing to our understanding of sodium ion storage mechanisms.

Copper-doped nanostructured MoS2 with distinct nanoscale morphology for efficient bacteria inactivation and catalytic degradation of antibiotics

Copper-doped nanostructured MoS2 with distinct nanoscale morphology for efficient bacteria inactivation and catalytic degradation of antibiotics

Influence of titanium nanoscale surface roughness on fibrinogen and albumin protein adsorption kinetics and platelet responses.

Biomaterials with nanoscale topography have been increasingly investigated for medical device applications to improve tissue-material interactions. This study assessed the impact of nanoengineered titanium surface domain sizes on early biological responses that can significantly affect tissue interactions. Nanostructured titanium coatings with distinct nanoscale surface roughness were deposited on quartz crystal microbalance with dissipation (QCM-D) sensors by physical vapor deposition. Physico-chemical characterization was conducted to assess nanoscale surface roughness, nano-topographical morphology, wettability, and atomic composition. The results demonstrated increased projected surface area and hydrophilicity with increasing nanoscale surface roughness. The adsorption properties of albumin and fibrinogen, two major plasma proteins that readily encounter implanted surfaces, on the nanostructured surfaces were measured using QCM-D. Significant differences in the amounts and viscoelastic properties of adsorbed proteins were observed, dependent on the surface roughness, protein type, protein concentration, and protein binding affinity. The impact of protein adsorption on subsequent biological responses was also examined using qualitative and quantitative in vitro evaluation of human platelet adhesion, aggregation, and activation. Qualitative platelet morphology assessment indicated increased platelet activation/aggregation on titanium surfaces with increased roughness. These data suggest that nanoscale differences in titanium surface roughness influence biological responses that may affect implant integration.

Analysis of nanoscale evolution features of microstructure of asphalt based on atomic force microscopy

Analysis of nanoscale evolution features of microstructure of asphalt based on atomic force microscopy

Improving the thermophysical aspects of innovative clay brick composites for sustainable development via TiO2 and rGO nanosheets

Improving the thermophysical aspects of innovative clay brick composites for sustainable development via TiO2 and rGO nanosheets

Nanocellulose: from biosources to nanofiber and their applications

Abstract Nanocellulose is a product of cellulose, a sustainable and plentiful resource. It’s distinctive nanoscale structure makes it a versatile, green and interesting material for a variety of applications. This article describes in detail the biosources of nanocellulose, the types and characteristics of nanocellulose, and the techniques used to produce nanocellulose fibers. The mechanical properties and morphologies of nanocellulose fibers are addressed in depth, along with their prospective applications in sectors, including paper packaging, building materials, composites, biomedicine, energy storage and filtration. In addition, the current state of nanocellulose research, including the opportunities in the field, as well as the future prospects of nanocellulose as a viable and sustainable material for a vast array of applications, are discussed.

STED imaging of endogenously tagged ARF GTPases reveals their distinct nanoscale localizations.

ADP-ribosylation factor (ARF) GTPases are major regulators of cellular membrane homeostasis. High sequence similarity and multiple, possibly redundant functions of the five human ARFs make investigating their function a challenging task. To shed light on the roles of the different Golgi-localized ARF members in membrane trafficking, we generated CRISPR-Cas9 knockins (KIs) of type I (ARF1 and ARF3) and type II ARFs (ARF4 and ARF5) and mapped their nanoscale localization with stimulated emission depletion (STED) super-resolution microscopy. We find ARF1, ARF4, and ARF5 on segregated nanodomains on the cis-Golgi and ER-Golgi intermediate compartments (ERGIC), revealing distinct roles in COPI recruitment on early secretory membranes. Interestingly, ARF4 and ARF5 define Golgi-tethered ERGIC elements decorated by COPI and devoid of ARF1. Differential localization of ARF1 and ARF4 on peripheral ERGICs suggests the presence of functionally different classes of intermediate compartments that could regulate bi-directional transport between the ER and the Golgi. Furthermore, ARF1 and ARF3 localize to segregated nanodomains on the trans-Golgi network (TGN) and are found on TGN-derived post-Golgi tubules, strengthening the idea of distinct roles in post-Golgi sorting. This work provides the first map of the nanoscale organization of human ARF GTPases on cellular membranes and sets the stage to dissect their numerous cellular roles.

Development of ε-poly(L-lysine) carbon dots-modified magnetic nanoparticles and their applications as novel antibacterial agents.

Magnetic nanoparticles (MNPs) are widely applied in antibacterial therapy owing to their distinct nanoscale structure, intrinsic peroxidase-like activities, and magnetic behavior. However, some deficiencies, such as the tendency to aggregate in water, unsatisfactory biocompatibility, and limited antibacterial effect, hindered their further clinical applications. Surface modification of MNPs is one of the main strategies to improve their (bio)physicochemical properties and enhance biological functions. Herein, antibacterial ε-poly (L-lysine) carbon dots (PL-CDs) modified MNPs (CMNPs) were synthesized to investigate their performance in eliminating pathogenic bacteria. It was found that the PL-CDs were successfully loaded on the surface of MNPs by detecting their morphology, surface charges, functional groups, and other physicochemical properties. The positively charged CMNPs show superparamagnetic properties and are well dispersed in water. Furthermore, bacterial experiments indicate that the CMNPs exhibited highly effective antimicrobial properties against Staphylococcus aureus. Notably, the in vitro cellular assays show that CMNPs have favorable cytocompatibility. Thus, CMNPs acting as novel smart nanomaterials could offer great potential for the clinical treatment of bacterial infections.

Innovative Approaches to Thermal Management in Next-Generation Electronics

In conclusion, the analysis and measurement of thermal properties are crucial for a wide range of applications in science, technology, and industry. For energy efficiency optimisation, the design of sophisticated materials, and the creation of cutting-edge technologies, it is essential to comprehend how heat is transmitted and handled within materials. Researchers can precisely evaluate thermal conductivity, heat capacity, and other thermal parameters using a variety of experimental methodologies, including both conventional and cutting-edge technologies. This enables accurate material characterisation and performance evaluation. The landscape of thermal management and energy conversion has been significantly shaped by nanostructured materials. Their distinct nanoscale characteristics provide chances to modify thermal behaviour, boost effectiveness, and add new features. Researchers are able to manage heat conduction, phonon behaviour, and charge transport through the use of designed nanostructures, which has led to breakthroughs in a variety of industries, including electronics, energy storage, thermoelectric devices, and more. In addition to promoting energy efficiency and waste heat recovery, these developments pave the path for sustainable solutions to the world’s rising energy needs and environmental problems. We are on the verge of ground-breaking discoveries that have the potential to restructure industries, enhance energy sustainability, and pave the way for a more effective and linked society as we continue to investigate and harness the complex behaviour of heat within materials.

Electrocatalytic CO 2 Reduction over Bimetallic Bi-Based Catalysts: A Review

Electrocatalytic CO ₂ Reduction over Bimetallic Bi-Based Catalysts: A Review

Regulation of cardiomyocyte adhesion and mechanosignalling through distinct nanoscale behaviour of integrin ligands mimicking healthy or fibrotic extracellular matrix.

The stiffness of the cardiovascular environment changes during ageing and in disease and contributes to disease incidence and progression. Changing collagen expression and cross-linking regulate the rigidity of the cardiac extracellular matrix (ECM). Additionally, basal lamina glycoproteins, especially laminin and fibronectin regulate cardiomyocyte adhesion formation, mechanics and mechanosignalling. Laminin is abundant in the healthy heart, but fibronectin is increasingly expressed in the fibrotic heart. ECM receptors are co-regulated with the changing ECM. Owing to differences in integrin dynamics, clustering and downstream adhesion formation this is expected to ultimately influence cardiomyocyte mechanosignalling; however, details remain elusive. Here, we sought to investigate how different cardiomyocyte integrin/ligand combinations affect adhesion formation, traction forces and mechanosignalling, using a combination of uniformly coated surfaces with defined stiffness, polydimethylsiloxane nanopillars, micropatterning and specifically designed bionanoarrays for precise ligand presentation. Thereby we found that the adhesion nanoscale organization, signalling and traction force generation of neonatal rat cardiomyocytes (which express both laminin and fibronectin binding integrins) are strongly dependent on the integrin/ligand combination. Together our data indicate that the presence of fibronectin in combination with the enhanced stiffness in fibrotic areas will strongly impact on the cardiomyocyte behaviour and influence disease progression.This article is part of the theme issue ‘The cardiomyocyte: new revelations on the interplay between architecture and function in growth, health, and disease’.

Visualizing Dynamic Environmental Processes in Liquid at Nanoscale via Liquid-Phase Electron Microscopy.

Visualizing the structure and processes in liquids at the nanoscale is essential for understanding the fundamental mechanisms and underlying processes of environmental research. Cutting-edge progress of in situ liquid-phase (scanning) transmission electron microscopy (LP-S/TEM) and inferred possible applications are highlighted as a more and more indispensable tool for visualization of dynamic environmental processes in this Perspective. Advancements in nanofabrication technology, high-speed imaging, comprehensive detectors, and spectroscopy analysis have made it increasingly convenient to use LP S/TEM, thus providing an approach for visualization of direct and insightful scientific information with the exciting possibility of solving an increasing number of tricky environmental problems. This includes evaluating the transformation fate and path of contamination, assessing toxicology of nanomaterials, simulating solid surface corrosion processes in the environment, and observing water pollution control processes. Distinct nanoscale or even atomic understanding of the reaction would provide dependable and precise identification and quantification of contaminants in dynamic processes, thus facilitating trouble-tracing of environmental problems with amplifying complexity.

Synthesis and Structural Characterization of Morphologically Distinct Nanoscale Hydroxyapatites

Synthesis and Structural Characterization of Morphologically Distinct Nanoscale Hydroxyapatites