Nano Research最新文献

Molecular diagnostic technologies empower new clinical opportunities in precision medicine. However, existing approaches face limitations with respect to performance, operation and cost. Biological molecules including proteins and nucleic acids are being increasingly adopted as tools in the development of new molecular diagnostic technologies. In particular, leveraging their complementary properties—the functional diversity of proteins and the precision programmability of nucleic acids—a wide range of protein-nucleic acid hybrid nanostructures have been developed. These hybrid structures take diverse forms, ranging from one-dimensional to three-dimensional hybrids, as static assemblies to dynamic machines, and possess myriad functions to recognize target biomarkers, encode vast information and execute catalytic activities. Motivated by recent advances in this area of molecular nanotechnology, we review the state-of-art design and application of various types of protein-nucleic acid hybrid nanostructures for molecular diagnostics, and present an outlook on the challenges and opportunities for emerging pre-clinical and clinical applications, highlighting the promise for earlier detection, more refined diagnosis and highly tailored treatment decision that ultimately lead to improved patient outcomes.

Direct ethanol fuel cells (DEFCs) have drawn attention for their simplicity, rapid start-up, high power density and environmental friendliness. Despite these advantages, the widespread application of DEFCs faces challenges, primarily due to the inadequate performance of anode and cathode catalysts. Pd-based materials have shown exceptional catalytic activity for both the ethanol oxidation reaction (EOR) and the oxygen reduction reaction (ORR). Alloying noble metals with rare earth elements has emerged as an effective strategy to further enhance the catalytic activity by modulating the electronic structure. In this study, we synthesized a series of palladium-rare earth (Pd₃RE) alloys supported on carbon to serve as bifunctional catalysts that efficiently promote both ORR and EOR. Compared to Pd/C, the Pd₃Tb/C catalyst exhibits 3.1-fold and 1.8-fold enhancement in activity for ORR and EOR, respectively. The charge transfer in the Pd₃Tb/C results in an electron-rich Pd component, thereby weakening the binding energy with oxygen species and facilitating the two reactions.

Topochemical transformation has emerged as a promising method for fabricating two-dimensional (2D) materials with precise control over their composition and morphology. However, the large-scale synthesis of ultrathin 2D materials with controllable thickness remains a tremendous challenge. Herein, we adopt an efficient topochemical synthesis strategy, employing a confined reaction space to fabricate ultrathin 2D Sn₄P₃ nanosheets in large-scale. By carefully adjusting the rolling number during the processing of Sn/Al foils, we have successfully fabricated Sn₄P₃ nanosheets with varied layer thicknesses, achieving a remarkable minimum thickness of two layers (~ 2.2 nm). Remarkably, the bilayer Sn₄P₃ nanosheets display an exceptional initial capacity of 1088 mAh·g⁻¹, nearing the theoretical value of 1230 mAh·g⁻¹. Furthermore, we reveal their high-rate property as well as outstanding cyclic stability, maintaining capacity without fading more than 3000 cycles. By precisely controlling the layer thickness and ensuring nanoscale uniformity, we enhance the lithium cycling performance of Sn₄P₃, marking a significant advancement in developing high-performance energy storage systems.

Anomalous thermal expansion, or other words, negative thermal expansion (NTE), resulting from the lattice contraction upon temperature increasing, has been an enduring topic for material science and engineering. The variation of a lattice go with the temperature is straightly originated from its electronic structures and is inseparable from those physical properties. In the past several decades, many efforts have been made to searching new series of NTE compounds or control the thermal expansion performance in order to supply various demands of different extreme applications. These development of new NTE systems also dependences on the theoretical studies. Here, we carried out theoretical calculation on CrB₂ and FeZr₂ with anisotropic negative thermal expansion. Intriguingly, theoretical calculations reveal that the binding of either Cr-Cr pair or Fe-Fe pair is relatively small. The results reveal that the origin of NTE is the ordered magnetic state during the increasing of temperature. The localized electrons would prevent the lattice parameters increase with heating, which shows macroscopic NTE phenomenon.

Interaction between heterogeneous, nanometer-sized building blocks (NSBBs) is fascinating from viewpoints of both structures and functions. We report the co-assembly of fullerene C₆₀ and a chiral silver nanocluster (Ag₆), which yields C₆₀ nanoarchitecture decorated with a small amount of Ag₆. While Ag₆ exhibits circular dichroism (CD) signal mainly in the ultraviolet (UV) region, the signal of the C₆₀-Ag₆ hybrid extends to visible region (over 700 nm). Up to five pairs of CD signals were distinguished, which match well with the absorption of the C₆₀ crystal. The successful chirality transfer from the guest of Ag₆ to C₆₀-dominated supramolecular system indicates that the “sergeants and soldiers” effect is valid in architectonics of NSBBs. In addition, the doping of Ag₆ leads to pronounced nonlinear optical response, paving a new way for the development of chiral optical materials.

High-entropy alloys (HEAs) are promising candidates for the electrocatalyst of hydrogen evolution reaction (HER) due to their unique properties such as cocktail electronic effect and lattice distortion effect. Herein, the ultrasmall (sub-2 nm) nanoparticles of PtRuCoNiCu HEA with uniform element distribution are highly dispersed on hierarchical N-doped carbon nanocages (hNCNC) via low-temperature thermal reduction, denoted as us-HEA/hNCNC. The optimal us-HEA/hNCNC exhibits excellent HER performance in 0.5 M H₂SO₄ solution, achieving an ultralow overpotential of 19 mV at 10 mA·cm⁻² (without iR-compensation), high mass activity of 13.1 A·mg_{noble metals}⁻¹ at −0.10 V and superb stability with a slight overpotential increase of 3 mV after 20,000 cycles of cyclic voltammetry scans, much superior to the commercial Pt/C (20 wt.%). The combined experimental and theoretical studies reveal that the Pt&Ru serve as the main active sites for HER and the CoNiCu species modify the electron density of active sites to facilitate the H* adsorption and achieve an optimum M-H binding energy. The hierarchical pore structure and N-doping of hNCNC support also play a crucial role in the enhancement of HER activity and stability. This study demonstrates an effective strategy to greatly improve the HER performance of noble metals by developing the HEAs on the unique hNCNC support.

The advancement of lithium-based batteries has spurred anticipation for enhanced energy density, extended cycle life and reduced capacity degradation. However, these benefits are accompanied by potential risks, such as thermal runaway and explosions due to higher energy density. Currently, liquid organic electrolytes are the predominant choice for lithium batteries, despite their limitations in terms of mechanical strength and vulnerability to leakage. The development of polymer electrolytes, with their high Young’s modulus and enhanced safety features, offers a potential solution to the drawbacks of traditional liquid electrolytes. Despite these advantages, polymer electrolytes are still susceptible to burning and decomposition. To address this issue, researchers have conducted extensive studies to improve their flame-retardant properties from various perspectives. This review provides a concise overview of the thermal runaway mechanisms, flame-retardant mechanisms and electrochemical performance of polymer electrolytes. It also outlines the advancements in flame-retardant polymer electrolytes through the incorporation of various additives and the selection of inherently flame-retardant matrix. This review aims to offer a comprehensive understanding of flame-retardant polymer electrolytes and serve as a guide for future research in this field.

VX is a highly toxic organophosphorus nerve agent that the Chemical Weapons Convention classifies as a Schedule 1. In our previous study, we developed a method for detecting organophosphorus compounds using peptide self-assembly. Nevertheless, the self-assembly mechanisms of peptides that bind organophosphorus and the roles of each peptide residue remain elusive, restricting the design and application of peptide materials. Here, we use a multi-scale computational combined with experimental approach to illustrate the self-assembly mechanism of peptide-bound VX and the roles played by residues in different peptide sequences. We calculated that the self-assembly of peptides was accelerated after adding VX, and the final size of assembled nanofibers was larger than the original one, aligning with experimental findings. The atomic scale details offered by our approach enabled us to clarify the connection between the peptide sequences and nanostructures formation, as well as the contribution of various residues in binding VX and assembly process. Our investigation revealed a tight correlation between the number of Tyrosine residues and morphology of the assembly. These results indicate a self-assembly mechanism of peptide and VX, which can be used to design functional peptides for binding and hydrolyzing other organophosphorus nerve agents for detoxification and biomedical applications.

Oxygen reduction reaction (ORR) occurs at the cathode of electrochemical devices like fuel cells and in the Huron-Dow process, reducing oxygen to water or hydrogen peroxide. Over the past years, various electrocatalysts with enhanced activity, selectivity, and durability have been developed for ORR. However, an atomic-level understanding of how materials composition affects electrocatalytic performance has not yet been achieved, which prevents us from designing efficient catalysts based on the requirements of practical applications. This is partially because of the polydispersity of traditional catalysts and their unknown structure dynamics in the electrocatalytic reactions. Here we establish a full-spectrum of atomically precise and robust Au_xAg_25-x(MHA)18 (x = 0–25, and MHA = 6-mercaptohexanoic acid) nanoclusters (NCs) and systematically investigate their composition-dependent catalytic performance for ORR at the atomic level. The results show that, with the increasing number of Au atoms in Au_xAg_25-x(MHA)₁₈ NCs, the electron transfer number gradually decreases from 3.9 for Ag₂₅(MHA)₁₈ to 2.1 for Au₂₅(MHA)₁₈, indicating that the dominant oxygen reduction product alters from water to hydrogen peroxide. Density functional theory simulations reveal that the Gibbs free energy of OOH adsorption (Δ_GOOH*) on Au₂₅ is closest to the ideal ΔG_OOH* of 4.22 eV to produce H₂O₂, while Ag alloying makes the ΔG_OOH* deviate from the optimal value and leads to the production of water. This study suggests that alloy NCs are promising paradigms for unveiling composition-dependent electrocatalytic performance of metal nanoparticles at the atomic level.

The growing demand for electric vehicles highlights the need for energy storage solutions with higher densities, spotlighting Li metal anodes as potential successors to traditional Li-ion batteries (LIBs). Achieving longer calendar aging life for Li metal anodes is crucial for their practical use, given their propensity for corrosion due to a low redox potential, which leads to compromised cycling stability and significant capacity loss during storage. Recent research investigated that this susceptibility is mainly dependent on the surface area of Li metal anode and the properties of the solid electrolyte interphase (SEI), particularly its stability and growth rate. Our research adds to this understanding by demonstrating that the amount of Li plating is a key factor in its corrosion during open-circuit storage, as assessed across various electrolytes. We discovered that increasing the Li plating amount effectively reduces Coulombic efficiency (C.E.) loss during aging, due to a lower surface area-to-Li ratio. This implies that the choice of electrolyte for optimal storage life should consider the amount of Li plating, with higher capacities promoting better storage characteristics.