Nanoscale Horizons最新文献

The use of two-dimensional or nanoscaled materials as active medium in resistive switching (RS) is becoming more and more frequent in the neuromorphic and in-memory computing. Although many works have focused their attention on the RS mechanism of the materials, less attention is devoted to understanding the role of the interfaces with the metallic electrodes, especially when the electrode is also used as substrate for the growth of the material. Indeed, a low temperature growth of the active material on the largest possible metallic substrate would greatly improve the scalability and compatibility with back-end-of-line processing of the resulting memristive devices. Here, we report that tellurium grown by vapour transport deposition at 100 °C on gold substrate improves its RS when the surface of the Au(111) shows the well-known herringbone reconstruction. Indeed, the morphology of the nanoscaled tellurium is influenced by the gold surface reconstruction and, in turn, its RS probed by conductive atomic force microscopy. By comparison with the un-reconstructed surface, a non-negligible reduction of the set and reset voltages is observed. These results demonstrate that proper interface engineering between the material and electrodes might turn out to be as important as the material itself for the memristive performance.

Structure-based DNA memory represents a paradigm shift from nucleotide-encoded storage, circumventing the costly repetitive synthesis and sequencing dependencies while harnessing the programmable architecture of DNA nanostructures. However, the absence of random-access capability has constrained practical implementation. Here, we implement a Boolean search-enabled random-access scheme for structural DNA memory, wherein data is encoded on DNA origami tiles with orthogonally dimensioned index strands (1D/2D/3D addressing). Boolean operations are executed by hybridizing biotinylated probes to target index combinations, enabling the magnetic extraction of specific files. Atomic force microscopy validation confirms the precise retrieval of data across single-, dual-, and triple-indexed libraries. This approach establishes a robust framework for enabling random access in complex structural DNA databases.

The widespread use of antibiotics has led to an increased number of antimicrobial-resistant (AMR) pathogens, highlighting the need for novel antibacterial nanomaterials with chemical and structural tunability. Here, we present the antibacterial properties/pathways of two molybdenum-based double transition metal (DTM) MXenes (Mo₂TiC₂T_x and Mo₂Ti₂C₃T_x) and compare them with Ti₃C₂T_x MXene. We demonstrate that the antibacterial effectiveness of these MXenes is concentration- and time-dependent, with prolonged exposure time being more influential at lower concentration levels (<25 μg mL⁻¹). Physical damage to E. coli cell walls by MXene nanoknives (sharp edges of MXene flakes), and disruption in metabolic functions through oxidative stress were key antibacterial pathways for Mo₂TiC₂T_x, Mo₂Ti₂C₃T_x, and Ti₃C₂T_x MXenes. A 1 h sonication of MXene solutions reduced their flake sizes (average lateral size of 234 ± 163 nm) and led to substantial improvement of their antibacterial performance by bolstering the availability of nanoknives for physical damage to bacterial cells. However, prolonged sonication (2 h) resulted in reduced antibacterial effectiveness, potentially due to morphological defects of MXene flakes. We also studied the metal ion release and disc inhibition zone, which revealed no direct correlation between the MXenes’ antibacterial properties and the leaching of ions or fragments. This study demonstrates the potential for improving the antibacterial effectiveness of molybdenum-containing DTM MXenes by controlling their chemical and structural characteristics.

Lithium–sulfur (Li–S) batteries offer a transformative theoretical energy density (∼2600 Wh kg⁻¹), positioning them as strong candidates for next-generation energy storage systems supporting the global shift toward renewable energy integration and electrified transportation. However, their commercial viability is hindered by challenges such as the polysulfide shuttle effect and safety concerns related to volatile liquid electrolytes. Polymer-based solid-state electrolytes present a compelling pathway to overcome these barriers, offering improved safety, processability, and design flexibility. This review critically examines recent advancements in polymer electrolytes for Li–S batteries, with a particular focus on nanoscale strategies to enhance ionic conductivity, electrochemical stability, and electrode–electrolyte interfacial compatibility. Special attention is paid to nanostructured polymer matrices, functional nanofillers, and interfacial engineering techniques. This review also explores emerging directions, including the development of adaptive “smart” electrolytes and the integration of machine learning for rational materials design. Finally, the environmental and sustainability profiles of polymer-based Li–S batteries are compared with those of conventional lithium-ion systems, considering life cycle aspects such as raw material sourcing, fabrication energy intensity, and global warming potential. This review aims to bridge the gap between nanoscale innovation and macroscopic energy challenges, highlighting the potential of polymer electrolytes to enable scalable, safe, and sustainable Li–S battery technologies.

Monolayered WS₂ exhibits a direct band gap, strongly bound excitons, trions and biexcitons as well as no inversion symmetry in the 2D crystal structure (D_3h), allowing frequency doubling by second-harmonic generation. The recent progress in colloidal synthesis of transition metal dichalcogenides enables the scalable production of phase-pure monolayer-dominated WS₂. In this work, we use parabolic mirror-assisted microscopy to investigate the linear and nonlinear optical properties of deposited colloidal WS₂. Spatial and spectral resolution of one- and two-photon photoluminescence and second-harmonic generation correlates structural motifs of the WS₂ layers including orientation and agglomeration to the local optical response. We find exciton and trion emission at 613 nm and 639 nm respectively, with significantly varying contribution to the overall intensity between one- and two-photon excitation. This is attributed to the increased carrier density under high fluences needed for two-photon excitation. By evaluating the second-harmonic generation intensity, the nonlinear susceptibility of colloidally synthesized WS₂ nanosheets is calculated to range from 4.28–7.55 nm V⁻¹, averaging higher than a commercial WS₂ monolayer reference sample. Our results show that colloidal WS₂ is suitable for large area coverage creating an isotropic WS₂ film, while retaining the highly sought after linear and nonlinear optical properties of WS₂ monolayers, even under surface ligand separated aggregation.

Nanoscale Horizons Scientific Editor Prof. Mark MacLachlan (University of British Columbia, Canada) introduces this hand-selected Editor’s Choice collection on inorganic-biomolecule nanomaterials. This collection features some of the exciting research developments published in Nanoscale Horizons in the past couple of years.

Recent advances in biofabrication demand bioinks that are not only biocompatible and mechanically suitable for tissue engineering, but also responsive to dynamic biological and electrical cues. Here, we introduce a DNA–viologen hybrid bioink system that rapidly forms a structurally defined hydrogel through interfacial gelation, enabling precise spatial control of gelation without requiring external triggers. The resulting hydrogel exhibits a hollow capsule morphology, tunable viscoelasticity, and excellent printability, making it suitable for soft tissue-direct patterning applications. Beyond its mechanical properties, this system integrates reversible electrochromic functionality, allowing dynamic optical responses under electrical stimulation. Taken together, this proof-of-concept study highlights how the integration of electroactive behavior with the programmability of DNA can open opportunities for multifunctional soft materials. The combination of rapid formation, structural adaptability, and electrical responsiveness underscores its promise in emerging applications, including wearable devices, biosensors, and stimuli-responsive platforms.

Two-dimensional (2D) fluorescence-excitation (PLE) spectroscopy offers a powerful way to analyse samples of semiconducting single-wall carbon nanotubes (SWCNTs). The one-to-one correspondence between the SWCNT chiral structure and its optically excited states allows for the identification of individual species based on peaks in 2D PLE data. Changes in the position, width and other features of the lineshape associated with a given peak reveal a plethora of information about the associated SWCNT chirality and e.g. its interactions with the environment. Consistent and physically relevant quantification of that information requires accurate fitting of the 2D data, which has long been hindered by the fact that a sufficiently accurate functional form for the excitation profile of SWCNTs was not known. Here we present a highly accurate analytical empirical model for the excitation lineshape and combine it with one for the emission lineshape in a 2D fitting model that produces accurate fits of 2D PLE maps for any SWCNT sample and allows straightforward extraction of lineshape features, including peak positions, linewidths and intensities as well as other relevant physical quantities such as phonon sidebands in the emission and excitation spectra.

Phase change materials have significant application prospects in thermal energy storage and management. However, challenges such as low thermal conductivity, liquid leakage and solid rigidity have hindered their practical applications. In this study, a dual encapsulation strategy was adopted, using a highly-oriented graphite framework (HOGF) as the large framework and a polyimide/carbon nanotube (PI/CNT) aerogel as the small framework to construct an oriented carbon skeleton with high thermal conductivity. Subsequently, it was impregnated with n-octadecane (OD), and composite phase change materials (OHPC-x) with bidirectional high thermal conductivity, heat storage and high photothermal performance were successfully prepared. The increase of OD endows OHPC with excellent heat storage capacity, and the enthalpy value of OHPC-2 can reach 164.46 J g⁻¹. In addition, the lamellar structure of the HOGF provides phonon transmission channels, endowing the OHPC composite with a relatively high in-plane thermal conductivity (5.8913 W m⁻¹ K⁻¹). CNTs, as thermally conductive fillers and light collectors, can not only expand the heat transfer area but also reduce thermal resistance. Their addition enabled OHPC to achieve an enhanced axial thermal conductivity (2.2934 W m⁻¹ K⁻¹) and a high photothermal conversion rate (86.9%). The developed composite material has achieved a perfect combination of multiple functions and holds great application potential in the efficient utilization of solar energy, building thermal management, and the protection of electronic equipment.

mRNA lipid nanoparticles (LNPs) have emerged as a leading delivery system for mRNA-based vaccines and therapeutics. However, a significant limitation of this system is the presence of poly(ethylene) glycol (PEG). It is widely known that repeated doses of PEG-based therapeutics can induce an anti-PEG antibody response, leading to the accelerated blood clearance (ABC) of LNP therapeutics requiring frequent dosing, as anti-PEG antibodies have been found present in a large proportion of the population. To address this issue, we developed a mouse model for LNP clearance after a repeated dose. We then synthesised LNPs with the PEG component replaced by a library of hydrophilic polymers: poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA), POEGMA-methacrylic acid (POEGMA (−)), POEGMA-2-(dimethylamino)ethyl methacrylate (POEGMA (+)), poly(N,N-dimethylacrylamide) (PDMA), and poly(N-(2-hydroxypropyl) methacrylamide) (PHPMA). Our results demonstrated that all three POEGMA LNPs, especially POEGMA (+) LNPs, exhibited minimal ABC effect after two weekly doses; in contrast, PDMA LNPs demonstrated significantly lower clearance in the presence of anti-PEG antibodies. This study highlights the potential of PEG-free polymer–LNPs as promising mRNA carriers that avoid rapid clearance with repeated administration.