Nanoscale Advances最新文献

Flexible substrates for sensing provide adaptable, lightweight, and highly sensitive platforms for detecting different substances. The flexibility of these substrates allows for seamless integration with complex shapes and dynamic surfaces, enabling monitoring in challenging conditions using methods such as surface-enhanced Raman spectroscopy (SERS). Here we outline a flexible metamaterial array sensor formed from plasmonic silver-coated nanoimprinted piezoelectric polyvinylidene fluoride film. We show that nanoscale array features can be prepared on the surface of the piezoelectric film using a facile nanoimprinting procedure. These nanoimprinted features act as polarization channels that enable plasmonic resonances, enhancing the SERS signal strength and improving reproducibility. We combine this effect with the inherent piezoelectric properties of polyvinylidene fluoride to further enhance the Raman signal strength upon mechanical deformation. Our results demonstrate a significant enhancement of the SERS signal when probed at a wavelength of 532 nm, achieving over an order of magnitude increase in signal strength for a range of analytes. This lightweight and flexible SERS substrate holds significant potential for applications in medical diagnostics, environmental monitoring, and trace detection, offering a highly sensitive and reproducible analytical platform.

Nucleic acid-based therapeutics have the ability to tackle a wide range of diseases and stress tolerance that present significant obstacles for conventional approaches in agriculture. RNA-based medicines have become a promising approach, using nanoformulation treatments to specifically target certain diseases. Nanoformulations offer numerous benefits in comparison to alternative treatment methods, such as precise administration, minimal toxicity, and medication loading compatibility due to their bioactivity. There are a variety of nanoformulations available today, such as liposomes, polymeric nanoparticles (NPs), magnetic NPs, nanogels, and solid lipid nanoparticles (SLNs). RNA-based therapy employs intracellular gene nanoparticles containing messenger RNA (mRNA), which play an important role in stress management and pest as well as disease control. The adoption of mRNA-based technology paves the way for future technological progress. This review focuses on elucidating the process underlying the development of RNA interference (RNAi) and the diverse array of nanocarriers employed for the transportation of RNAi. Currently, this technique is being employed in the field of crop protection to combat diseases, pests, and environmental stress. The article highlights the benefits of RNAi mediated nanoformulations and discusses the significant obstacles that must be overcome to improve the viability of this technology for future applications.

Metal-organic frameworks (MOFs) have attracted increasing attention for the removal of organic pollutants in wastewater via photocatalysis. Here, we design a multivariate modification of ZIF-9 to tune its electronic properties for use in visible light photocatalysis. A controllable synthesis of ZIF-9 and its multivariate forms with the incorporation of copper and the 2-imidazolecarboxaldehyde (ica) ligand was carried out. The materials are tested for the removal of the model dye methylene blue (MB) by a heterogeneous photo-Fenton-like reaction at neutral pH and room temperature. Cu-ZIF-9-ica (UPO-3) shows high photocatalytic activity under both visible and ultraviolet A (UVA) light, achieving 94% MB degradation in 45 min, compared to 65% MB degradation in 120 min using bare ZIF-9. The study revealed a first-order rate constant of 0.0475 min^-1 for Cu-ZIF-9-ica compared to 0.0088 min^-1 for ZIF-9 under visible light. The improvement of the catalyst was clearly attributed to the co-incorporation of Cu and the ica ligand in the MOF, which reduces the band gap, in agreement with DFT calculations. Reproducibility and recyclability tests proved that Cu-ZIF-9-ica can be used for at least 3 cycles without a significant loss of efficiency, making it a promising material for the study and application of wastewater treatment.

This study provides compelling experimental evidence of the synergistic effects of reaction pressure, oxidation state, and catalyst morphology on the C₂₊ selectivity of copper (Cu) oxide catalysts in electrochemical CO₂ reduction (ECR). We employed femtosecond laser structuring and thermal treatments to synthesize Cu(0), Cu(i), Cu(ii), and a mixed oxidation state catalyst Cu(x) with characteristic micro- and nano-morphologies. The optimal CO₂ pressure for maximizing C₂₊ productivity in aqueous bicarbonate media was established by assessing the reaction products at different imposed pressures in a custom-designed, pressurizable two-compartment cell. Among Cu(0), Cu(i), and Cu(ii), thermally produced Cu(i) was the only unstructured catalyst exhibiting ethylene gas-phase selectivity. Nanostructuring enhanced the C₂₊ selectivity such that all three oxidation states could produce ethylene. More importantly, the nanostructured Cu(x) comprising well-dispersed Cu(0), Cu(i), and Cu(ii), exhibited ethylene as well as ethane production - a characteristic associated with the synergistic effects of undercoordinated Cu states in stabilizing reaction intermediates and facilitating charge transfer to yield longer C₂₊ products. This work provides important insights into the key factors influencing C₂₊ selectivity in Cu-based catalysts, establishing the basis for an informed design to yield high-energy density products.

Nanoparticle accumulation at tumor sites has been well reported in vivo, where targeting typically shows increased retention, but challenges remain for clinical translation. This work examines the effect of targeting ligand binding affinities and nanoparticle size on retention and transport through a solid tumor. We first show using cell affinity assays that modifying a wildtype (WT) anti-epidermal growth factor receptor (EGFR) affibody-enzyme fusion protein into a UV-photocrosslinkable (N23BP) version led to a significant decrease in affinity, whether as a free protein or as a conjugate to silica nanoparticles. Despite the reduced EGFR affinity, all protein conjugated nanoparticles showed binding and uptake to EGFR-overexpressing HTB9 bladder cancer cells as detected by confocal microscopy and flow cytometry. Next, transport studies of the protein conjugated nanoparticles using monoculture spheroids revealed that spheroid binding was higher for 17 nm particles bound with the WT proteins than N23BP, which was expected based on their respective K _D values. However, the 17 nm particles conjugated with the photocrosslinkable N23BP affibody-enzymes showed an altered distribution profile that peaked further into the spheroid than the WT nanoparticle conjugates or in the absence of UV treatment. We correlate this finding with increased transport and retention of the photocrosslinked N23BP-nanoparticle conjugates in 3D spheroids to both the lower binding affinity of the affibodies for EGFR and the ability to introduce covalent linkages between the affibody and cell receptor. The larger 40 nm protein-conjugated nanoparticles showed limited penetration regardless of affinity or photocrosslinking on a 12 h timescale but did show overall increased transport after 24 h.

As plasmonic absorbers attract considerable attention in the fields of solar energy harvesting, sensors, and cloaking technology, achieving dynamic tuning holds promise for multifunctional applications. However, existing designs face challenges in achieving real-time dynamic regulation across the visible band. In this study, we propose an innovative approach to achieve dynamic broadband absorption at visible wavelengths via an electrochemical lithium metal battery. Through rigorous experimentation and simulation, we demonstrate that the dynamic absorber achieves remarkable reversibility, with 80% absorption at lithium deposition states and a 40% modulation amplitude in reflectance over 30 cycles. At the intersection of the plasmonic absorber and lithium battery, our results may provide insights for light detection such as the monitoring environment.

Methyl parathion (MP) is a widely used pesticide; it is recognized as being toxic to both target and non-target species, posing serious risks to environmental and human health. Monitoring and controlling MP residues is thus essential, necessitating the development of innovative sensors that are highly sensitive, selective, and reproducible. In the present study, an efficient electrochemical MP sensor is proposed based on silver nanoparticles (AgNPs) in conjunction with graphene oxide/ionic liquid (GO/IL) on screen printed electrodes (AgNPs@GO/IL@SPCE). The AgNPs were synthesized via a cost-effective wet-chemical process and characterized using UV-Vis spectroscopy and transmission electron microscopy (TEM). The modified electrodes were characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The active surface area and charge transfer were examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), respectively. The modified electrodes' electrocatalytic performance towards the reduction of MP was investigated by CV, complemented by semiempirical quantum chemistry calculations to elucidate the interaction and the electrochemical reduction mechanism of MP. The sensor demonstrates a remarkable limit of detection of 0.009 μmol L^-1 within a linear range of 0.025 to 200 μmol L^-1. It has an excellent analytical performance in terms of selectivity, reproducibility, and long-term stability over 60 days. The designed sensor was effectively used to inspect MP in groundwater and surface water samples, with recovery values ranging from 95.60% to 99.68%.

Controlling the layer-by-layer chemistry and structure of nanomaterials remains a crucial focus in nanoscience and nanoengineering. Specifically, the integration of atomically thin semiconductors with antiferromagnetic two-dimensional materials holds great promise for advancing research. In this work, we successfully demonstrate a new synthesis approach for high-crystallinity CrCl₃/MoS₂ van der Waals heterostructures via a thermodynamically optimized chemical vapor transport (CVT) process on c-sapphire (0001) substrates. The 2H-MoS₂ layers can be grown as monolayers or with varying twist angles whereas the deposition of CrCl₃ layers in a second step forms the well-defined heterostructure. Of particular significance are the sharp and clean edges and faces of the crystals, indicating high-quality interfaces in the heterostructures. Raman spectroscopy, AFM and HRTEM confirm the monocrystalline character and precise structure of these layered nanomaterials, in which their intrinsic properties are preserved and unaffected by strain. This can pave the way for next-generation applications, particularly in valleytronics, opto-spintronics, and quantum information processing.

Zhenyuan Xia, Yeye Wen and Muqiang Jian introduce the Nanoscale Advances themed issue on carbon nanomaterials for smart applications.

The drugs clopidogrel and clonidine are frequently used to treat cardiovascular diseases, which are the leading cause of mortality worldwide. Since these medications are frequently taken in combination, it is crucial to examine their molecular interactions. Therefore, herein, the bandgap energy, chemical potential, chemical hardness and softness parameters were calculated using a density functional theory (DFT)-based method. In addition, infrared (IR) spectrum, natural bond orbital (NBO), molecular electrostatic potential (MEP), electron localization function (ELF) and total density of states (TDOS) plots complemented the analysis. Clonidine exhibited greater sensitivity to electrophilic attack, while the electronic affinity of clopidogrel was slightly higher. According to the MEP map, negative charge density was located on the oxygen atoms of clopidogrel, and the positive charge was located on the nitrogen atoms of clonidine. Notably, both the drugs exhibited similar reactivity in water. Clopidogrel was less reactive than clonidine, and the interaction between the molecules occurred via physisorption, which was in agreement with the TDOS plot. NBO analysis revealed a low charge variation, in accordance with the physical adsorption-like bonding between the drugs. The lowest energy for the clopidogrel-clonidine interaction was attained via the formation of four H bonds, as indicated by a significant intensive peak at 3360 cm^-1 in the IR spectrum. Hydrogen bonds played a crucial role in the controlled drug delivery application as it allowed moderate and reversible drug adsorption, facilitating drug release in the biological environment. IR spectra also supported the absence of degradation or chemical reaction between the drugs, confirming the preservation of the individual active pharmaceutical ingredient.