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We explore the large-scale behavior of a stochastic model for nanoparticle growth in an unusual parameter regime. This model encompasses two types of reactions: nucleation, where n monomers aggregate to form a nanoparticle, and growth, where a nanoparticle increases its size by consuming a monomer. Reverse reactions are disregarded. We delve into a previously unexplored parameter regime. Specifically, we consider a scenario where the growth rate of the first newly formed particle is of the same order of magnitude as the nucleation rate, in contrast to the classical scenario where, in the initial stage, nucleation dominates over growth. In this regime, we investigate the final size distribution as the initial number of monomers tends to infinity through extensive simulation studies utilizing state-of-the-art stochastic simulation methods with an efficient implementation and supported by high-performance computing infrastructure. We observe the emergence of a deterministic limit for the particle's final size density. To scale up the initial number of monomers to approximate the magnitudes encountered in real experiments, we introduce a novel approximation process aimed at faster simulation. Remarkably, this approximating process yields a final size distribution that becomes very close to that of the original process when the available monomers approach infinity. Simulations of the approximating process further support the conjecture of the emergence of a deterministic limit. [ABSTRACT FROM AUTHOR]

Grafting polymer chains to the surface of nanoparticles overcomes the challenge of nanoparticle dispersion within nanocomposites and establishes high-volume fractions that are found to enable enhanced material mechanical properties. This study utilizes coarse-grained molecular dynamics simulations to quantify how the shear modulus of polymer-grafted nanoparticle (PGN) systems in their glassy state depends on parameters such as strain rate, nanoparticle size, grafting density, and chain length. The results are interpreted through further analysis of the dynamics of chain conformations and volume fraction arguments. The volume fraction of nanoparticles is found to be the most influential variable in deciding the shear modulus of PGN systems. A simple rule of mixture is utilized to express the monotonic dependence of shear modulus on the volume fraction of nanoparticles. Due to the reinforcing effect of nanoparticles, shortening the grafted chains results in a higher shear modulus in PGNs, which is not seen in linear systems. These results offer timely insight into calibrating molecular design parameters for achieving the desired mechanical properties in PGNs. [ABSTRACT FROM AUTHOR]

We energetically predict the morphology of Pd, Ag, Au, and Pt nanoparticles on (0001) sapphire substrates, using density functional theory (DFT) simulations and the well-known Young–Dupre equation. In all cases, the contact angles exceed 90 ° , indicating that the nanoparticles are spherical. Notably, Au nanoparticles exhibit a higher contact angle than those of their counterparts. The validity of the proposed a b i n i t i o nanoparticle morphology prediction approach based on DFT simulations was assessed in comparison with our previous experimental findings pertaining to the time variation of the full width at half maximum (FWHM) of the resonant peak. Furthermore, the diffusivities of single Pd, Ag, Au, and Pt atoms on the substrate were evaluated by calculating the activation energy, offering insights into the underlying physics governing the timing of FWHM peaks. The analysis confirms a higher diffusivity of Au and Ag compared with Pd and Pt. According to the comparison between DFT and experiment results, although no clear relation is observed between the contact angles and timing of FWHM peaks, the diffusivity of sputtered atoms may influence the timing of FWHM peaks. Thus, timing can help to clarify the nanoparticle size, rather than shape. [ABSTRACT FROM AUTHOR]

The influence of a dielectric layer with an embedded 2D array of metal nanoparticles on the spectral characteristics of a distributed Bragg reflector is theoretically studied and numerically validated. A significant dependence of the reflectivity of the hybrid structure on the location of the nanoparticle array relative to the maxima and minima of the optical field in the surface dielectric layer is demonstrated. It is found that the application of a dilute ensemble of nanoparticles (the interparticle distance is from 2 to 5 times larger than the nanoparticle size) in the region of high optical field localization makes it possible to obtain a total suppression of reflection in the photonic bandgap range of distributed Bragg reflector. Contrariwise, if the optical field is almost zero at the nanoparticle array location, its impact on the scattered light is negligible, that is, the resonant nanoparticles are masked by a highly reflective photonic structure. The target wavelength can be tuned inside the photonic bandgap range by adjusting the shape of nanoparticles and interparticle distance in the array. [ABSTRACT FROM AUTHOR]

Understanding the influence of a crowded intracellular environment on the structure and solvation of DNA functionalized gold nanoparticles (ss-DNA AuNP) is necessary for designing applications in nanomedicine. In this study, the effect of single (Gly, Ser, Lys) and mixture of amino acids (Gly+Ser, Gly+Lys, Ser+Lys) at crowded concentrations is examined on the structure of the ss-DNA AuNP using molecular dynamics simulations. Using the structural estimators such as pair correlation functions and ligand shell positional fluctuations, the solvation entropy is estimated. Combining the AuNP–solvent interaction energy with the solvation entropy estimates, the free energy of solvation of the AuNP in crowded solutions is computed. The solvation entropy favours the solvation free energy which becomes more favourable for larger effective size of AuNP in crowded solutions relative to that in water. The effective size of AuNP depends on the different propensity of the crowders to adsorb on Au surface, with the smallest crowder (Gly) having the highest propensity inducing the least effective AuNP size as compared to other single crowder solutions. In mixed crowded solutions of amino acids of variable size and chemistry, distinctive local adsorption of the crowders on the gold surface is observed that controls the additive or non-additive crowding effects which govern an increase (in Gly+Ser) or decrease (in Gly+Lys) in nanoparticle effective size respectively. The results shed light into the fundamental understanding of the influence of intracellular crowding on structure of ss-DNA AuNP and plausible employability of crowding as a tool to design programmable self-assembly of functionalized nanoparticles. [ABSTRACT FROM AUTHOR]

In this study, modification of regular masks using composite nanofibers containing porous nanostructures has been considered in order to increase their efficiency in dealing with new threats. For this purpose, polystyrene was used as a low-cost polymer to prepare nanofibers and modify the surface of the respirator mask. ZIF-8 nanostructures with different sizes (14, 23, 65,144, and 265 nm) and zinc oxide nanoparticles, with an approximate size of 36 nm, were added to polymer nanofibers.2-methyl imidazole and Zn(NO3)2 were used to synthesize nanostructures. Two different methods (injection and stabilization) were used to incorporate nanostructures into fibers. The percentage of ZIF-8 and ZnO nanostructures were 0.5 and 2 wt% respects to polystyrene, respectively. Synthesis reactions and preparation of fibrous filters were carried out at ambient temperature. FESEM, FTIR, EDAX, TGA, and XRD techniques were used to identify the prepared nanoparticles and fibers. To evaluate the performance of the modified filters, their efficiency in removing suspended particles below 2.5 microns as well as CO2, SO2 and NO2 gases was surveyed. The results showed that ZIF nanoparticles with arbitrary sizes have been synthesized and successfully stabilized on the surface of nanofibers. Modifying the surface of the commercial mask by electrospinning method resulted in forming a fibrous layer with an approximate diameter of 700 nm and the presence of stabilized nanostructures in both methods was confirmed using FESEM images. Adding the nanofibers to the surface of the filter significantly increased their efficiency in removing suspended particles and toxic gases. The optimized modified filter contained ZIF-8 with14nm dimension and could remove sub-micron particles, CO2, NO2, and SO2 gases by 99, 91, 87, and 86%, respectively, making it as effective as commercially available N-95 masks. Moreover, it was observed that the incorporation of nanostructures by the stabilization method was more effective in improving the filtering efficiency of the fibrous mask. [ABSTRACT FROM AUTHOR]

This study is aimed at the in situ preparation and antibacterial study of silver nanoparticles within the matrix of an eco‐friendly, biocompatible, biodegradable, and bioavailable biopolymer (chitosan) to form Chi–AgNP film via multiple noncovalent interactions between the organic polymer and the nanoparticles. The film is fully characterized by infrared and ultraviolet spectroscopy, scanning electron microscopy, transmission electron microscopy, X‐ray photoelectron spectroscopy, and thermogravimetric analysis. The characterization confirms the successful incorporation of silver nanoparticles into the polymeric network. Infrared spectroscopy reveals peaks corresponding to the vibration of functional groups present in chitosan with enhanced intensity and blueshifts caused by the presence of silver nanoparticles. Well‐monodispersed spherical silver nanoparticles with an average size of 10 nm are observed in the Chi–AgNP film. The surface plasmon resonance at 447 nm is consistent with a typical silver plasmon. Furthermore, the antibacterial effects on E. coli and S. aureus were determined and attributed to the release of AgNPs observed by UV absorption. [ABSTRACT FROM AUTHOR]

Nanoparticles can offer an alternative approach to fabricate phase‐change materials. The chemical synthesis of GeTe nanoparticles using organometallic precursors exploits high‐boiling solvents and relatively high temperatures (close or even above crystallization temperatures), as reported in the available literature. The aim of this work is the preparation of GeTe nanoparticles by a low‐temperature synthetic method exploiting new organometallic precursors and common organic solvents. Indeed, different preparation methods and characterization of GeTe nanoparticles is discussed. The characterization of the prepared nanomaterial was performed on the basis of X‐ray diffraction, transmission electron microscopy, scanning electron microscopy with energy dispersive X‐ray spectroscopy, laser ablation time‐of‐flight mass spectrometry, Raman scattering spectroscopy, and dynamic light scattering. The results show that the low‐temperature synthetic route leads to amorphous GeTe nanoparticles. Exploited organometallic precursor is stabilised by neutral ligand which can be isolated after the reaction and repeatedly used for further reactions. Furthermore, GeTe nanoparticle size can be tuned by the conditions of the synthesis. [ABSTRACT FROM AUTHOR]

Catalytic reduction of organic pollutants using metal nanoparticles (MNPs) as nanocatalyst is a promising approach. The widespread application of MNPs have led to an increase demand for their production. The green biosynthesis of MNPs using microbes is becoming increasingly important as they are benign and environmentally friendly. In this work, Deinococcus wulumuqiensis (D. wulumuqiensis) with high resistance to stresses was applied for the green preparation of different MNPs, including palladium nanoparticles (Pd NPs), silver nanoparticles (Ag NPs), and Pd−Ag bimetallic nanoparticles (Pd−Ag BNPs). The resultant MNPs exhibited a face‐centered cubic structure, with average size of 6.70 (Pd NPs), 6.24 (Ag NPs), and 6.13 nm (Pd−Ag BNPs), respectively. FT‐IR spectra indicated that the proteins and polysaccharides expressed by D. wulumuqiensis could potentially contributed to the formation of MNPs. The application of as‐prepared biocatalyst in catalytic degradation of pollutant dyes demonstrated that Pd−Ag BNPs had greater degradation ability of 4‐nitrophenol (95.1 %) and Rhodamine B (85.1 %) than monometallic nanoparticles. The pseudo‐first‐order kinetics results further indicated the superior catalytic ability of Pd−Ag BNPs, with rate constant of 0.450±0.009 (4‐nitrophenol) and 1.54×10−2 min−1 (Rhodamine B), respectively. Thus, the present study confirms that D. wulumuqiensis represents a promising candidate for the biosynthesis of Pd‐based nanoparticles with small size, which exhibited potential applications as bionanocatalyst in the degradation of water pollutants. [ABSTRACT FROM AUTHOR]

In this paper, platinum nanoparticles with a size of less than 50 nm were rapidly and successfully synthesized in low-temperature molten salt using a microwave method. The morphology and structure of the product were characterized by SEM, TEM, EDX, XRD, etc. The TEM and SEM results showed that the prepared product was a nanostructure with concave and uniform size. The EDX result indicated that the product was pure Pt, and the XRD pattern showed that the diffraction peaks of the product were consistent with the standard spectrum of platinum. The obtained Pt/C nanoparticles exhibited remarkable electrochemical performance in a formic acid catalytic oxidation reaction (FAOR), with a peak mass current density of 502.00 mA·mg−1Pt and primarily following the direct catalytic oxidation pathway. In addition, in the chronoamperometry test, after 24 h, the mass-specific activity value of the Pt concave NPs/C catalyst (10.91 mA·mg−1Pt) was approximately 4.5 times that of Pt/C (JM) (2.35 mA·mg−1Pt). The Pt/C NPs exhibited much higher formic acid catalytic activity and stability than commercial Pt/C. The microwave method can be extended to the preparation of platinum-based alloys as well as other catalysts. [ABSTRACT FROM AUTHOR]

Small‐angle X‐ray scattering (SAXS) is a widely used method for nanoparticle characterization. A common approach to analysing nanoparticles in solution by SAXS involves fitting the curve using a parametric model that relates real‐space parameters, such as nanoparticle size and electron density, to intensity values in reciprocal space. Selecting the optimal model is a crucial step in terms of analysis quality and can be time‐consuming and complex. Several studies have proposed effective methods, based on machine learning, to automate the model selection step. Deploying these methods in software intended for both researchers and industry raises several issues. The diversity of SAXS instrumentation requires assessment of the robustness of these methods on data from various machine configurations, involving significant variations in the q‐space ranges and highly variable signal‐to‐noise ratios (SNR) from one data set to another. In the case of laboratory instrumentation, data acquisition can be time‐consuming and there is no universal criterion for defining an optimal acquisition time. This paper presents an approach that revisits the nanoparticle model selection method proposed by Monge et al. [Acta Cryst. (2024), A80, 202–212], evaluating and enhancing its robustness on data from device configurations not seen during training, by expanding the data set used for training. The influence of SNR on predictor robustness is then assessed, improved, and used to propose a stopping criterion for optimizing the trade‐off between exposure time and data quality. [ABSTRACT FROM AUTHOR]

BACKGROUND: Nanotechnology has been widely applied in agricultural science. During the process of reducing metal toxicity and accumulation in rice, nanomaterials exhibit size effects. However, there is limited knowledge regarding these size effects. We aim to explore the impact of fertilizer with various sizes of ZnO nanoparticles (ZnO‐NPs) on rice growth and cadmium (Cd) accumulation and to elucidate the potential mechanism of Cd reduction in rice. Foliar applications of different concentrations (0.5 and 2 mmol L−1) and different sizes (30 and 300 nm ZnO‐NPs) of zinc (Zn) fertilizer (Zn(NO3)2) were performed to investigate the effects on rice growth, Cd accumulation and subcellular distribution, and the expression of Zn–Cd transport genes. RESULTS: The results suggested that all the foliar sprayings can significantly reduce the Cd concentrations in rice grains by 41–61% with the highest reduction in the application of ZnO‐NPs with large size and low concentration. This is related to the enhancement of Cd fixation in leaf cell walls and downregulation of Cd transport genes (OsZIP7, OsHMA2, OsHMA3) in stem nodes. Foliar ZnO‐NPs applications can increase the Zn concentration in grains by 9–21%. Foliar applications of Zn(NO3)2 and small‐sized ZnO‐NPs promoted plant growth and rice yield, while the application of large‐sized ZnO‐NPs significantly reduced rice growth and yield. CONCLUSION: The study suggests that the rice yield and Cd reduction are dependent on the size and concentration of foliar spraying and the use of large‐sized ZnO‐NPs is the most effective strategy when considering both yield and Cd reduction comprehensively. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This study presents an easy method for synthesizing ultrafine NixFe1–xFe2O4 nanoparticles with adjustable composition (x = 0–.8), followed by their stabilization into ferrofluids. Structural identification of the crystalline structure, lattice points, and grain boundaries from the broadened diffraction peaks reveal an average crystalline size of the nanoparticles as 10–16.5 nm. Transmission electron microscopy images reveal spherical magnetite nanoparticles with a particle size ranging from 6 to 13 nm, consistent with diffraction studies. In ferrofluids, the NixFe1–xFe2O4 nanoparticles are stabilized in kerosene with oleic acid, a surfactant. Absorbance data of the ferrofluids is seen in the 200–400 nm wavelength region of UV–vis spectra. The magnetic properties of the samples are probed using a Superconducting Quantum Interference Device. The synthesized samples exhibit superparamagnetic behavior at room temperature (300 K). The saturation magnetization of the samples decreases with an increase in Ni composition (x = 0–.8), ranging from 54 to 28 emu/g. This study explores the magnetic and magneto‐optical properties of NixFe1–xFe2O4 ferrofluids. Magneto‐viscosity of ferrofluids is also studied, and the final application of such ferrofluids in data storage, catalysis, and biomedical applications is discussed. [ABSTRACT FROM AUTHOR]

This study revolves around the synthesis of poly (amino acid)-based polymers, specifically designed as block copolymers incorporating poly (glutamic acid) and poly (ethylene glycol), with varying glutamic acid moieties. Extensive characterization of these block copolymers was carried out using Fourier Transform Infrared and proton nuclear magnetic resonance (1H NMR) spectroscopy. The integration of the potent anti-cancer agent, doxorubicin, into these constructs was successfully achieved. The determination of nanoparticle sizes was accomplished through dynamic laser light scattering; while, zeta potential measurements provided insights into surface charges. Following the drug loading into nanomicelles, the release profiles were investigated under conditions simulating the tumor-specific acidic pH and physiological blood pH (7.4). In vitro cytotoxicity evaluations were performed, revealing dose and time-dependent reactions for both free and loaded doxorubicin against the MCF-7 breast cancer cell line. Additionally, the mechanisms of cellular uptake were explored using confocal laser scanning microscopy and flow cytometry. The findings unveiled that the cellular uptake of free doxorubicin predominantly follows a diffusion process; while, the drug loaded within nanoparticles is internalized via endocytosis. The nanoparticles were skillfully engineered to possess optimal size, shape, and surface charge, thereby showcasing their potential as proficient vehicles for targeted drug delivery. In summary, this study not only demonstrates the successful synthesis and meticulous characterization of poly (amino acid)-based nanocarriers but also underscores their biocompatibility, favorable attributes, and promising capabilities as effective platforms for precise and targeted drug delivery. [ABSTRACT FROM AUTHOR]

Proton-exchange-membrane fuel cells demand highly efficient catalysts for the oxygen reduction reaction, and core-shell structures are known for maximizing precious metal utilization. Here, we reported a controllable "carbon defect anchoring" strategy to prepare Pt1Ni1@Pt/C core-shell nanoparticles with an average size of ~2.6 nm on an in-situ transformed defective carbon support. The strong Pt–C interaction effectively inhibits nanoparticle migration or aggregation, even after undergoing stability tests over 70,000 potential cycles, resulting in only 1.6% degradation. The stable Pt1Ni1@Pt/C catalysts have high oxygen reduction reaction mass activity and specific activity that reach 1.424 ± 0.019 A/mgPt and 1.554 ± 0.027 mA/cmPt2 at 0.9 V, respectively, attributed to the optimal compressive strain. The experimental results are generally consistent with the theoretical predictions made by our comprehensive microkinetic model which incorporates essential kinetics and thermodynamics of oxygen reduction reaction. The consistent results obtained in our study provide compelling evidence for the high accuracy and reliability of our model. This work highlights the synergy between theory-guided catalyst design and appropriate synthetic methodologies to translate the theory into practice, offering valuable insights for future catalyst development. Efficient and stable catalysts for oxygen reduction reactions are difficult to achieve due to slow kinetics and degradation. Here, the authors use a 'carbon defect anchoring' strategy to create Pt1Ni1@Pt core-shell nanoparticles with high activity and durability. [ABSTRACT FROM AUTHOR]

Nanomaterial-mediated plant genetic engineering holds promise for developing new crop cultivars but can be hindered by nanomaterial toxicity to protoplasts. We present a fast, high-throughput method for assessing protoplast viability using resazurin, a non-toxic dye converted to highly fluorescent resorufin during respiration. Protoplasts isolated from hypocotyl canola (Brassica napus L.) were evaluated at varying temperatures (4, 10, 20, 30 ˚C) and time intervals (1–24 h). Optimal conditions for detecting protoplast viability were identified as 20,000 cells incubated with 40 µM resazurin at room temperature for 3 h. The assay was applied to evaluate the cytotoxicity of silver nanospheres, silica nanospheres, cholesteryl-butyrate nanoemulsion, and lipid nanoparticles. The cholesteryl-butyrate nanoemulsion and lipid nanoparticles exhibited toxicity across all tested concentrations (5-500 ng/ml), except at 5 ng/ml. Silver nanospheres were toxic across all tested concentrations (5-500 ng/ml) and sizes (20–100 nm), except for the larger size (100 nm) at 5 ng/ml. Silica nanospheres showed no toxicity at 5 ng/ml across all tested sizes (12–230 nm). Our results highlight that nanoparticle size and concentration significantly impact protoplast toxicity. Overall, the results showed that the resazurin assay is a precise, rapid, and scalable tool for screening nanomaterial cytotoxicity, enabling more accurate evaluations before using nanomaterials in genetic engineering. [ABSTRACT FROM AUTHOR]

Boron neutron capture therapy (BNCT) as a binary targeted particle radiotherapy strategy has shown potent anti‐cancer potential. However, biological barriers and restricted blood supply pose challenges in achieving adequate boron concentration within deep‐seated tumor lesions. BNCT with other anti‐cancer therapies, such as X‐ray radiotherapy and photothermal therapy, is devised to address the limitations of BNCT efficiency. However, the potential risk of organ‐accumulating toxicity and treatment complexity of dual exogenous activation hinders its development. To address this problem, newly redox‐responsive boron nano‐chains (RBNC) are reported that combine BNCT and endogenous chemodynamic therapy (CDT)‐enhanced ferroptosis. RBNC specifically activates nanoparticle size conversion (large‐to‐small) in response to GSH/H2O2 in the tumor microenvironment, releasing boron delivery agents boron quantum dots (BQD) and Fe3+. RBNC exhibits negligible systemic toxicity while demonstrating high boron accumulation at tumor. Meanwhile, the introduction of Fe3+ not only produces ·OH through reaction with H2O2, but also depletes GSH and reduces GPX4 activity in tumors, resulting in amplified intracellular oxidative stress and chemodynamically enhanced ferroptosis. Thus, the work provides a strategy to solve the problem of insufficient boron concentration and poor targeting of boron delivery agents and fill the gaps of BNCT combined with CDT and ferroptosis. [ABSTRACT FROM AUTHOR]

Nanoparticles synthesized from green sources have attracted great recognition in the present times, which can be ascribed to their distinctive attributes and diversified applicability. Therefore, the present study employed Ocimum basilicum seed extract to synthesize silver nanoparticles. UV–vis spectrophotometry revealed strenuous peaks for different concentrations of silver nanoparticles ranging between 400 and 430 nm. The average crystal size calculated using X-ray diffraction analysis was 6.7 nm. Energy-dispersive X-ray analysis clearly displayed the presence of silver ions in the elemental structure of the synthesized nanoparticles. The morphology of synthesized nanoparticles revealed by scanning electron microscopy was documented in terms of spherical shape surrounded by an organic layer and nanoparticle size was estimated to be in between 10 and 80 nm. The nanoparticles exhibited substantial antibacterial activity against 46 foodborne bacterial isolates and 15 clinical isolates of Klebsiella pneumoniae, with the largest inhibition zones measuring 24 and 13 mm, respectively. Minimum inhibitory concentration values ranged between 500 and 800 µl/ml for various isolates. The antibacterial effect of all antibiotics revealed considerable enhancement when combined with nanoparticles. The calculated fractional inhibitory concentration index values were < 1 validating excellent synergism between nanoparticles and all antibiotics except ciprofloxacin against the majority of bacterial isolates. Interestingly, the biogenic nanoparticles showed significant antioxidant potential with IC50 value of 165 µg/ml as well as anti-inflammatory activity with an IC50 value of 82 µg/ml. Conclusively, the seed extract of Ocimum basilicum can be prospected for the development of antibacterial silver nanoparticles against pathogenic bacteria. [ABSTRACT FROM AUTHOR]

Red‐emitting nanophosphors have a multirole in improvising the next‐generation bulk/micro/nano‐level lighting devices, particularly in refining white light quality and device performance. Nonetheless, it is difficult to synthesize nanosized phosphors with good yield and paralleled high absorption efficiency both in UV and blue regions, which is critical for modern lighting. Herein, new Mg14Ge4.99+σO24‐x+δFx: Mn4+ red nanoparticles with sizes below 100 nm are designed to improve not only the luminescence but also the blue light absorption. This approach has validated the applicability of red‐emitting nanophosphors into flexible UV and blue nitride nanowire light‐emitting‐diodes (LEDs), and commercial bulk LEDs, for the first time, with boosted intensity and color superiority for a variety of lighting utilizations. For these phosphor LEDs (pc‐LEDs), optimized red nanophosphor with an external quantum efficiency of ≈44.5%, color purity of ≈100%, and thermal stability of ≈72% at 150 °C is used. The optimized nanophosphor is combined with a flexible UV‐AlGaN/GaN nanowire LED and a blue‐InGaN/GaN‐LED. The resultant devices show promising red electroluminescence without any degradation at elevated currents. Finally, several unfamiliar LED packaging is designed with yellow and red phosphors implemented on 2 sets of double LED units to reach CRI > 85. The re‐premeditated LED packages are useful for high‐definition lighting. [ABSTRACT FROM AUTHOR]

Developing efficient oxygen electrocatalysts with low cost, high catalytic activity, and robust stability remains a formidable challenge for rechargeable zinc–air batteries (ZABs). Herein, highly dispersed ultrasmall PtPdFeCoNi high‐entropy alloy nanoparticles with a size of ≈ 2 nm and randomly distributed multimetallic single atoms spatially immobilized on the 3D hierarchically ordered porous nitrogen‐doped carbon skeleton (denoted as PtPdFeCoNi/HOPNC) are successfully synthesized via ultra‐rapid Joule heating process. The spatial immobilization on 3D HOPNC skeleton is the key to the high dispersion of multi‐active sites of oxygen electrocatalysts, and the formed hierarchical pore structure is conducive to the successful construction of the rapid mass transfer channel. As a result, the as‐prepared PtPdFeCoNi/HOPNC exhibits a positive half‐wave potential of 0.866 V versus RHE for oxygen reduction reaction (ORR), a low overpotential of 310 mV at 10 mA cm−2 for oxygen evolution reaction (OER), and low Tafel slopes for both ORR and OER. Furthermore, ZAB using PtPdFeCoNi/HOPNC as bifunctional oxygen catalysts exhibits excellent rate performances and superior cycling stability, surpassing that of a commercial Pt/C‐RuO2 mixture. The spatial immobilization strategy of HOPNC provides a new idea for the design and synthesis of efficient catalysts for various applications. [ABSTRACT FROM AUTHOR]

Pharmaceutical formulations are increasingly based on drug nanoparticles or carrier nanoparticles encapsulating drugs or mRNA molecules. Sizes and monodispersity of the nanoparticles regulate bioavailability, pharmacokinetics and pharmacology. Microfluidic mixers promise unique conditions for their continuous preparation. A novel microfluidic antisolvent precipitation device was realized by two-photon-polymerization with a mixing channel in which the organic phase formed a sheet with a homogeneous thickness of down to 7 μm completely wrapped in the aqueous phase. Homogeneous diffusion through the sheet accelerates mixing. Optical access was implemented to allow in-situ dynamic light scattering. By centering the thin sheet in the microchannel cross-section, two important requirements are met. On the one hand, the organic phase never reaches the channel walls, avoiding fouling and unstable flow conditions. On the other hand, in the sheet positioned at the maximum of the parabolic flow profile the nanoparticle velocities are homogenized which enables flow-compensated Dynamic Light Scattering (flowDLS). These unique features allowed in-situ particle size determination for the first time. Monitoring of lipid nanoparticle precipitation was demonstrated for different rates of solvent and antisolvent flows. This breakthrough innovation will not only enable feedback control of nanoparticle production but also will provide new insights into the dynamics of nanoparticle precipitation. [ABSTRACT FROM AUTHOR]

Optical tweezers revolutionized the manipulation of nanoscale objects. Typically, tunable manipulations of optical tweezers rely on adjusting either the trapping laser beams or the optical environment surrounding the nanoparticles. Here, tunable and switchable trapping using nanoparticles made of a phase‐change material (vanadium dioxide or VO2) are achieved. By varying the intensity of the trapping beam, transitions of the VO2 between monoclinic and rutile phases are induced. Depending on the nanoparticles' sizes, they exhibit one of three behaviors: small nanoparticles (in the settings, radius <0.12$<0.12$ wavelength λ$\lambda$) remain always attracted by the laser beam in both material phases, large nanoparticles (>0.22λ$>0.22 \lambda$) remain always repelled. However, within the size range of 0.12−0.22λ$0.12\!-\!0.22\lambda $, the phase transition of the VO2 switches optical forces between attractive and repulsive, thereby pulling/pushing them toward/away from the beam center. The effect is reversible, allowing the same particle to be attracted and repelled repeatedly. The phenomenon is governed by optical Mie modes of the nanoparticles and their alterations during the phase transition of the VO2. This work provides an alternative solution for dynamic optical tweezers and paves a way to new possibilities, including optical sorting, light‐driven optomechanics and single‐molecule biophysics. [ABSTRACT FROM AUTHOR]

This review summarizes the progress in the research on polyoxometalate (POM)-decorated gold (Au) and silver (Ag) core–shell structures (Au/Ag@POMs), emphasizing their substantial application potential in catalysis, medicine, and biology. It outlines the central strategies for fabricating Au/Ag@POMs with diverse morphologies and dimensions, leveraging POMs as protective ligands and reducing agents as well as for ligand exchange. Of particular note is the focus on the analysis of the nanoparticle size, shape, and intricate architecture of POM shells using cryo-electron microscopy techniques. By integrating recent findings on atomically precise POM-stabilized nanoclusters, this review delves deeper into understanding surface interface structures, intrinsic atomic architectures, and electronic interactions between POM shells and metallic cores. Collectively, advancements in this field underscore significant strides in the controllable synthesis and precise structural manipulation of Au/Ag@POM architectures, thus paving the way for engineering high-performance metal catalysts. [ABSTRACT FROM AUTHOR]

Highlights This study evaluated the percolation threshold in polymer nanocomposites and its dependence on the aggregation/agglomeration phenomenon. The main objective of the investigation was to propose a particular method that besides revealing the impact of different involved parameters on the percolation threshold could also provide useful information regarding the system characteristics. In line with that, a specific geometrical structure was employed to represent the clusters and assess the variation of the percolation threshold and characteristics of the polymer/particle interphase region. The findings were applied in an improved form of the percolation theory to perform validation against the related experimental data. Improvement was conducted by involving the impact of the newly estimated percolation threshold, aggregations/agglomerations, interphase region, and so forth. Also, specific theories were employed to define the electrical conductivity of the nanoparticle clusters and interphase region. The results showed that the percolation threshold is directly affected by the content of the nanoparticles and the characteristics of the aggregates/agglomerates. Besides, it was revealed that parameters, such as the size of nanoparticles, physical characteristics of the polymer matrix and interphase region, dispersion quality, etc. may substantially affect the percolation threshold and subsequently other physical properties of the system, such as electrical conductivity. A structural approach toward understanding the percolation phenomenon. Defining the particular dependence of percolation threshold on dispersion quality. Estimating the content of aggregates/agglomerates using percolation theory. Improving the percolation theory to predict the electrical conductivity. Applying the scaling theory to define the electrical conductivity of the interphase. [ABSTRACT FROM AUTHOR]

In this research, tantalum nanoparticles were prepared by the laser ablation method and the effect of an electric field on their structural properties was investigated. The optical absorption spectra were studied to comprehend the optical properties of nanoparticles. Size and morphology of nanoparticles are illustrated by TEM images. The average size of tantalum nanoparticles is 19 and 45 nm for synthesized samples without and with electric fields, respectively. By applying an electric field, the morphology of nanoparticles changed from spherical to tangled shapes. XRD analysis showed the crystalline structure of nanoparticles. The investigation of bending and stretching of molecular functional groups and the measurement of the hydrodynamic radius were done by FTIR, RAMAN and DLS analyses, respectively. FTIR, RAMAN, XRD and DLS analyses confirm the structure. EDX spectra confirmed the existence of ingredients. The stability of colloidal is indicated by zeta potential analysis. Photoluminescence spectra reveal nanoparticle properties. As the electric field increases, the size of nanoparticles increased, morphology changes from spherical, and oxidation increases. [ABSTRACT FROM AUTHOR]

ABSTRACT Corrosion is a major problem and protective coatings offer an effective solution. However, organic coatings are often associated with microcracks caused by the evaporation of solvents during coating preparation. This study investigates the use of titanium dioxide (TiO2) nanoparticles as a coating additive to protect mild steel surfaces. Additionally, doping TiO2 with tin (Sn) is believed to enhance its properties due to the reduced size of the nanoparticles. These nanoparticles were synthesised using the sol–gel method and subjected to various analyses. The coated mild steel samples were prepared using the dip‐coating method and immersed in 3.5 wt.% sodium chloride (NaCl) solution for 30 days. Electrochemical impedance spectroscopy (EIS) and Tafel polarisation showed that the Sn‐doped TiO2 nanoparticles as an additive improved the corrosion resistance, as evidenced by a positive shift in corrosion potential (Ecorr) and reduced corrosion current density (Icorr). [ABSTRACT FROM AUTHOR]

Two different kinds of ZnO nanoparticles (NPs) with distinct particle sizes were synthesized by a precipitation method. For the first time, the effects of two distinct sizes ZnO NPs on the growth, photoluminescence properties and kojic acid (KA) yield of Aspergillus oryzae (A. oryzae) were examined. The findings showed that ZnO-A and -B NPs, with average particle sizes of 11.93 nm and 34.41nm, respectively, exhibited a hexagonal crystal structure. It was found that when the concentration of NPs was below 100μg/mL, ZnO NPs were nontoxic and served as activators to stimulate the growth of A. oryzae, and the biomass of solid and liquid medium, the total integral emission intensity, the content of extracellular protein and total organic carbon and KA yield of A. oryzae grown with ZnO-A (ZnO-B) NPs were about 2.19 (1.97), 2.47 (1.56), 1.67 (1.16), 2.45 (1.95), 0.47 (0.50) and 2.07 (1.37) times more than that of control sample (without NPs), respectively. [ABSTRACT FROM AUTHOR]

We report on the synthesis of SnO2 nanoparticles and SnO2:CNT hybrids, via a one-step solgel method. Herein, we investigate the influence of the synthesis conditions on their physical, chemical, optical and electrochemical properties. The crystalline structure, nanoparticle size and morphology are assessed by X-ray diffraction and transmission electron microscopy. The chemical states are elucidated by X-ray photoelectron and Raman spectroscopies. Their electrochemical behavior is studied by cyclic voltammetry. Overall, an oxygen-poor environment during the synthesis leads to smaller SnO2 nanoparticles, along with an increased number of surface defects. Photoluminescence spectroscopy demonstrates that under an oxygen-poor environment, bridging-oxygen vacancies are more abundant. Additionally, SnO2 nanoparticles containing a higher amount of oxygen vacancies exhibit a higher cycling stability of 90%. The cycling stability is further enhanced in hybrid SnO2:CNT. The electrochemical behavior is corroborated to the surface defects and in turn, the band bending mechanism in SnO2 n-type semiconductor. [ABSTRACT FROM AUTHOR]

In this work, carboxymethyl starch‐xanthan gum nanoparticles (CXN) with different ratios are prepared by ethanol precipitation method. The effects of different ratios, NaCl content, and pH on the particle size and zeta potential of the nanoparticles are investigated, as well as the rheological properties and stability of the CXN emulsions. The results show that with the increase of xanthan gum (XG), the particle size, and zeta potential of the nanoparticles decrease and the prepared emulsions have higher shear stress and viscosity, as well as greater thermal and storage stability. Changes in pH and NaCl concentration significantly affect the particle size and zeta potential values of the nanoparticles. Excess acids or bases increase the viscosity of the emulsions. At low salt concentrations (0.05 M), the emulsion viscosity increases significantly, after which the emulsion viscosity decreases with increasing salt concentration. Neutral pH conditions at room temperature are not conducive to the stability of the emulsions. At high temperatures (100 °C), high salt concentrations, excessive acids or bases can destabilize emulsions. This study provides a new way to reduce the particle size of nanoparticles and a feasible strategy for developing long‐term stable Pickering emulsion. [ABSTRACT FROM AUTHOR]

The synthesis of monodisperse and stable alginate nanoparticles (ALG-NPs) was achieved through the crosslinking of sodium alginate with Ca2+ ions within sodium bis(2-ethylhexyl)sulfosuccinate (AOT) reverse micelles (RMs) as nano-templates. This study addresses the challenge of controlling the size and stability of nanoparticles, which is critical for their applications in drug delivery and tissue engineering. We explored the effects of varying the water content, the choice of non-polar solvent, and the pH of the resuspension medium on nanoparticle formation. Using both n-heptane and isopropyl myristate (IPM) to form AOT RMs, we found that nanoparticle size increased with water content in both solvents, attributed to differing degrees of crosslinking efficiency influenced by the proximity of alginate and calcium ions at lower water content. Notably, IPM produced smaller and more crosslinked ALG-NPs than n-heptane, likely due to its impact on interfacial interactions. Additionally, raising the pH of the resuspension medium resulted in smaller NPs due to enhanced alginate availability for cross-linking. These findings highlight the potential of AOT RMs as versatile templates for generating polymeric nanoparticles with precise control over their characteristics. The significant role of solvent choice and pH in tailoring nanoparticle properties is underscored, providing valuable insights for future applications. The controlled size and stability of these ALG-NPs make them excellent candidates for drug delivery systems and tissue engineering, given their biocompatibility and biodegradability. [ABSTRACT FROM AUTHOR]

CO2 hydrogenation to methanol has emerged as a promising strategy for achieving carbon neutrality and mitigating global warming, in which the supported Pd/In2O3 catalysts are attracting great attention due to their high selectivity. Nonetheless, conventional impregnation methods induce strong metal‐support interaction (SMSI) between Pd and In2O3, which leads to the excessive reduction of In2O3 and the formation of undesirable PdIn alloy in hydrogen‐rich atmospheres. Herein, we innovatively synthesized Pd/In2O3 nanocatalysts by the electrostatic self‐assembly process between surface‐modified composite precursors with opposite charges. And the organic ligands concurrently serve as Pd nanoparticle protective agents. The resultant Pd/In2O3 nanocatalyst demonstrates the homogeneous distribution of Pd nanoparticles with controllable sizes on In2O3 supports and the limited formation of PdIn alloy. As a result, it exhibits superior selectivity and stability compared to the counterparts synthesized by the conventional impregnation procedure. Typically, it attains a maximum methanol space‐time yield of 0.54 gMeOH h−1gcat−1 (300 °C, 3.5 MPa, 21,000 mL gcat−1 h−1). Notably, the correlation characterization results reveal the significant effect of small‐size, highly dispersed Pd nanoparticles in mitigating MSI. These results provide an alternative strategy for synthesizing highly efficient Pd/In2O3 catalysts and offer a new insight into the strong metal‐support interaction. [ABSTRACT FROM AUTHOR]

One of the physical methods for obtaining magnetite nanoparticles (NPs) is electron beam physical vapor deposition (EB PVD), which requires complex equipment, but allows obtaining a significant amount of pure (ligand-free) NPs. The biomedical application of such NPs is less studied than materials from other synthesis methods. The objective is to study the effect of pure magnetite NPs in the NaCl matrix obtained by EB PVD on hematological indicators, gases, electrolytes and parameters of iron metabolism in the blood of intact animals. The physical characteristics of NPs were studied using high-resolution transmission electron microscopy, scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy mapping, electron energy-loss spectroscopy, selected area electron diffraction and fast Fourier transform. In vivo experiments were conducted on albino male rats, which were injected with solution of magnetite-sodium chloride NPs (1.35 mg Fe/kg). After 3 and 72 h, hematological parameters, blood gases, electrolytes, and serum iron were determined. The synthesized NPs had an average size of 11 nm. They were identified as magnetite, where polycrystals and single crystals were present. The absence of contamination in crystal boundaries, clear orientation and orderliness of atoms in crystals were established. The administration of NPs in the sodium chloride matrix to animals was characterized by a transient increase in the main indicators of red blood accompanied by an increase in the saturation of erythrocytes with hemoglobin and their mean volume after 3 h. It did not worsen blood gases and pH, but decreased blood Na+ content after 72 h. The investigated NPs caused changes in the parameters of serum iron characteristic to iron preparations, which after 3 h were smaller compared to the reference iron drug, and after 72 h—similar to it. More intense rapid effects on hematological parameters at lower serum iron indicate greater activity of the studied pure magnetite NPs obtained by EB PVD syntesis compared to the reference iron preparation. Highlights: Pure magnetite nanoparticles in the NaCl matrix were obtained by EB PVD. They were studied using high-resolution transmission electron microscopy. These nanoparticles had a size of 11 nm, clear orientation and orderliness of atoms in crystals. In healthy animals, they caused a transient increase in red blood indicators. They did not worsen blood gases and pH, but decreased Na+ content in the blood. The nanoparticles caused changes in the serum iron typical to iron preparations. These changes were not toxic and lasting due to compensatory reactions. [ABSTRACT FROM AUTHOR]

This article reveals how apparently similar looking nanoparticles with same size, shape, and mass may exhibit widely varying Brownian diffusivity due to inherent features of nanoscale dynamics. Such variabilities may, in certain cases, reach order of magnitude fluctuations depending on the interfacial and bulk properties of the Brownian body. Accordingly, the theory explains several unanswered questions in connection to submicron systems including anomalous thermal properties of nanofluids and strangely varying transmittivities of biologically originated particulate droplets. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles have been synthesized using green synthesis from Echium amoenum Fisch. &C.A.Mey. extract. The extract of this flower was used to reduction of silver nitrate solution and stabilization of formed silver nanoparticles. The extract of this flower contains different anthocyanin compounds, polyphenols, and vegetable stearic fatty acids that can contribute in reduction and stabilization of silver nanoparticles. Characterization of the nanoparticles was performed using X-ray diffraction method (XRD), dynamic light scattering (DLS), UV–Visible spectrum, and open aperture Z-scan method. The measurements showed that stable nanoparticles with an average size of about 54 nm were synthesized and the use of this extract was successful. Adding a few droplets of the extract to the nano-colloid made the peak of localized surface plasmon resonance (LSPR) clearer. Also, the trend of absorption spectrum changes with the addition of droplets and their nonlinear absorption changes were investigated. Nonlinear optical measurements also showed that silver nanoparticles synthesized by this method exhibit reversed saturation absorption which is due to multi-photon absorption and electrostriction effects. This green synthesis method can lead to the synthesis of stable and high-performance silver nanoparticles with high potential in electro-optic devices and can be considered as an environmentally friendly and low-cost synthesize method. [ABSTRACT FROM AUTHOR]

Background: Cancer is the most lethal disease in humans, accounting for one out of every six fatalities. The most frequent type of cancer among women is breast cancer, followed by cervix cancer. Iron oxide nanoparticles, due to their superparamagnetic traits, are one of the most widely used nanomaterials for diagnosing and treating breast cancer. For site-specific medication delivery, biotin was coupled with magnetite nanoparticles. Materials and Methods: The dextran-coated IONP was synthesized by a simple coprecipitation process and biotin was attached to the surface of dextran via a carboxylic/amine group. X-ray Diffractometer, Thermal gravimetric Analysis, Fourier Transformed Infrared Spectrometer, Atomic Force Microscopy and Vibrating Sample Magnetometer were used to investigate the structural, morphological, and magnetic properties of the produced materials. Results and Discussion: The iron oxide nanoparticle particle size was determined to be 325 nm. The MTT assay of IONPs and dextran-coated biotin-conjugated IONPs with low IC50 values of 24.18 μg/mL and 1.66 μg/mL exhibit cytotoxicity toxicity against MCF 7 cells, whereas the cytotoxicity of biotin-linked IONPs higher when compared with pure iron oxide. Conclusion: Iron oxide nanoparticle and dextran-coated biotin-conjugated iron oxide nanoparticle results confirmed the anti-breast cancer efficacy on human breast cancer cells by causing effective cytotoxicity and ensuring the drug delivery to a specific site. [ABSTRACT FROM AUTHOR]

Titanium dioxide nanoparticles, or TiO2 NPs, have shown potential in the fight against a range of diseases, including bacteria, viruses, fungi and parasites. Doping metals with nanoparticles modify their size and magnetic characteristics by decreasing the energy band gap and mixing spins and electrical charges. Furthermore, it has been shown that owing to their higher surface-to-volume ratio and improved ability to interact with bacterial cells, smaller metal-doped nanoparticles have better antibacterial action. Due in large part to their production, TiO3-NPs have outstanding antifungal and antibacterial capabilities. The major mechanism of TiO3-NPs' antibacterial activity is their potent oxidizing capacity, which produces superoxide and hydroxyl anion radicals. Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli are just a few of the pathogens against which TiO2 NPs have been shown to have antibacterial ability. Review topics will include the most recent discoveries in the sectors of water treatment, agriculture and medicine as well as the synthesis of TiO3- nanoparticles and their antimicrobial actions. TiO2 NPs as antibacterial agents: prospects and challenges will also be highlighted in the review. [ABSTRACT FROM AUTHOR]

The growing demand for hydrogen–air fuel cells with a proton-exchange membrane has increased interest in the development of scalable technologies for the synthesis of Pt/C catalysts that will allow us to fine-tune the microstructure of such materials. We have developed a new in situ technique for controlling the kinetics of the transformation of a platinum precursor into its nanoparticles and deposited Pt/C catalysts, which might be applicable during the liquid-phase synthesis in concentrated solutions and carbon suspensions. The technique is based on the analysis of changes in the redox potential and the reaction medium coloring during the synthesis. The application of the developed technique under conditions of scaled production has made it possible to obtain Pt/C catalysts with 20% and 40% platinum loading, containing ultra-small metal nanoparticles with a narrow size distribution. The electrochemically active surface area of platinum and the mass activity of synthesized catalysts in the oxygen electroreduction reaction have proved to be significantly higher than those of commonly used commercial analogs. At the same time, despite the small size of nanoparticles, the catalysts' degradation rate turned out to be the same as that of commercial analogs. [ABSTRACT FROM AUTHOR]

In this research, biogenic selenium nanoparticles were produced by the fungi Yarrowia lipolytica, and the biological activity of its nanoparticles was studied for the first time. The electron microscopy analyses showed the production of nanoparticles were intracellular and the resulting particles were extracted and characterized by XRD, zeta potential, FESEM, EDX, FTIR spectroscopy and DLS. These analyses showed amorphous spherical nanoparticles with an average size of 110 nm and a Zeta potential of −34.51 ± 2.41 mV. Signatures of lipids and proteins were present in the capping layer of biogenic selenium nanoparticles based on FTIR spectra. The antimicrobial properties of test strains showed that Serratia marcescens, Klebsiella pneumonia, Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis were inhibited at concentrations between 160 and 640 μg/mL, while the growth of Candida albicans was hindered by 80 μg/mL of biogenic selenium nanoparticles. At concentrations between 0.5 and 1.5 mg/mL of biogenic selenium nanoparticles inhibited up to 50% of biofilm formation of Klebsiella pneumonia, Acinetobacter baumannii, Staphylococcus aureus and Pseudomonas aeruginosa. Additionally, the concentration of 20–640 μg/mL of these bioSeNPs showed antioxidant activity. Evaluating the cytotoxicity of these nanoparticles on the HUVEC and HepG2 cell lines did not show any significant toxicity within MIC concentrations of SeNPs. This defines that Y. lipolytica synthesized SeNPs have strong potential to be exploited as antimicrobial agents against pathogens of WHO concern. [ABSTRACT FROM AUTHOR]

Coating of magnetic nanoparticles with functional polymers increases the applicability of these nanomaterials. A modular approach to functionalizing these polymer coatings can be achieved using click chemistry. This work reports the synthesis of magnetic nanoparticles coated with a dopamine anchoring group containing polymer with furan groups as side chain residues. Using the 'graft-to' approach, polymers are coated onto magnetic nanoparticles using a simple place exchange reaction. Various analytical techniques were used to characterize the polymer-coated nanoparticles for their size and surface composition. Utilization of poly(ethylene glycol) (PEG)-based polymer renders the magnetic nanoparticles water dispersible. The presence of the furan ring on the polymer brushes enables their facile functionalization using a maleimide group-bearing molecule under catalyst-free conditions. A hydrophobic fluorescent dye, used as a model drug, is conjugated onto the nanoparticles using the Diels-Alder reaction. One can anticipate that the facile fabrication and functionalization of these clickable polymer-coated magnetic nanoparticles will be attractive for various biomedical applications. [ABSTRACT FROM AUTHOR]

Nanoparticle-enhanced laser-induced breakdown spectroscopy (NELIBS) represents a promising tool for detecting trace elements. This work improves NELIBS by substituting metal nanoparticles with nano-silica particles to achieve rapid detection of Cs elements at low concentrations. This substitution effectively prevents cluster formation and simplifies the experiment preparation process. The research optimizes factors such as target movement speed, nanoparticle concentration, and nanoparticle size to identify the optimal experimental parameters. Comparative analysis of the 3D morphology of laser ablation areas with and without nanoparticles reveals that evenly distributed nano-silica particles on the target surface provide the most effective colloidal particle lens array (CPLA) effect, and increasing the roughness of the target surface thereby enhancing the quality of laser ablation. With a laser frequency of 10 Hz, optimal characteristic spectral signals are achieved when the target movement speed exceeds 2 mm/s. Under conditions of a concentration of 0.1 mg/mL and an average particle size of 50 nm, the greatest enhancement effect on Cs element LIBS characteristic spectral signals is observed. Consequently, the limit of detection (LOD) and the limit of quantitation (LOQ) of elemental Cs by LIBS technology are reduced to 0.45 mg/L and 1.51 mg/L, respectively, facilitating real-time detection of Cs element at low concentrations. In addition, the nano-silica particles have also had a certain enhancement effect on the spectral signal of elemental properties in the target, proving that enhancing the LIBS characteristic spectral signal using nano-silica particles is a feasible method. [ABSTRACT FROM AUTHOR]

The size-dependent photoluminescence (PL) blue shift in organometal halide perovskite nanoparticles has traditionally been attributed to quantum confinement effects (QCEs), irrespective of nanoparticle size. However, this interpretation lacks rigor for nanoparticles with diameters exceeding the exciton Bohr radius ( r B ). To address this, we investigated the PL of MAPbBr3 nanoparticles (MNPs) with diameters ranging from ~2 to 20 nm. By applying the Brus equation and Burstein–Moss theory to fit the PL and absorption blue shifts, we found that for MNPs larger than r B , the blue shift is not predominantly governed by QCEs but aligns closely with the band filling effect. This was further corroborated by a pronounced excitation-density-dependent PL blue shift (Burstein−Moss shift) at high photoexcitation densities. Additionally, trap-state filling was also found to be not a negligible origin of the PL blue shift, especially for the smaller MNPs. The time-resolved PL spectra (TRPL) and excitation-density-dependent TRPL are collected to support the coexistence of both filling effects by the high initial carrier density (~1017–1018 cm−3) and the recombination dynamics of localized excitons and free carriers in the excited state. These findings underscore the combined role of the band filling and trap-state filling effects in the size-dependent PL blue shift for solution-prepared MNPs with diameters larger than r B , offering new insights into the intrinsic PL blue shift in organometal halide perovskite nanoparticles. [ABSTRACT FROM AUTHOR]

Breast cancer is one of the deadliest cancers for women, so cell labeling and therapy of breast cancer become imperative. In this work, dextran- and carboxymethyl dextran–coated Fe3O4 nanoparticles (Fe3O4@DEX and Fe3O4@CMD) were well synthesized through the co-precipitation method. The dextran and carboxymethyl dextran coating reduces the average particle size of Fe3O4 nanoparticles from 10.9 to 4.0–5.5 nm, and the coated samples exhibit average hydrodynamic diameters ranging from 31 to 110 nm. The coating promotes the dispersibility of nanoparticles. Saturation magnetization is reduced from 60.3 to 5.6–7.1 emu/g in the coated MNPs due to the large weight ratio of the coating layer and the decrease in particle size. Hemolysis and cytotoxicity assay results indicate the excellent biocompatibility of Fe3O4 nanoparticles. The cellular uptake assay confirms that both dextran- and carboxymethyl dextran–coated Fe3O4 nanoparticles are easily taken in by breast cancer cells. Comprehensively considering dispersion, biocompatibility, and cellular uptake, the Fe3O4@CMD is more suitable for application in the bio-labeling of breast cancer cells. The SAR values of the Fe3O4@DEX and Fe3O4@CMD range from 19.2 to 30.7 W/g. The SAR value is mainly influenced by the hydrodynamic diameter in the coated samples. The Fe3O4@CMD20 shows the maximum SAR value of 30.7 W/g and has potential application in magnetic hyperthermia therapy. [ABSTRACT FROM AUTHOR]

In order to control pathogenic microorganisms, three polymer compositions were prepared and tested. First, a water-soluble positively charged polycomplex was synthesized via the electrostatic binding of anionic polyacrylic acid to an excess of polyethylenimine to enhance the biocidal activity of the polycation. Second, an aqueous solution of AgNO3 was added to the polycomplex, thus forming a ternary polycation-polyanion-Ag1+ complex with an additional antimicrobial effect. Third, the resulting ternary complex was subjected to UV irradiation, which ensured the conversion of Ag1+ ions into Ag nanoparticles ranging in size mainly from 10 to 20 nm. Aqueous solutions of the polymer compositions were added to suspensions of the Gram-positive bacteria S. aureus and the Gram-negative bacteria P. aeruginosa, with the following main results: (a) Upon the addition of the binary polycomplex, 30% or more of the cells survived after 20 h. (b) The ternary complex killed S. aureus bacteria but was ineffective against P. aeruginosa bacteria. (c) When the ternary complex with Ag nanoparticles was added, the percentage of surviving cells of both types did not exceed 0.03%. The obtained results are valuable for the development of antibacterial formulations. [ABSTRACT FROM AUTHOR]

Ultrahigh molecular weight polymers display outstanding properties and have great application potential. However, the traditional polymerization methods have inevitable disadvantages that challenge the green synthesis of ultrahigh molecular weight polymers. The paper achieved an ultrahigh molecular weight poly (trifluoroethyl methacrylate) via a novel polymerization and discussed the mechanistic, kinetic, and experimental aspects. The combination of palladium nanoparticles with ethyl 2-bromopropionate has been identified as an exceedingly efficient system for initiating the polymerization of trifluoroethyl methacrylate. An ultrahigh molecular weight poly (trifluoroethyl methacrylate) with a number-average molecular weight up to 3.03 × 106 Da has been synthesized at a feeding molar ratio of [poly (trifluoroethyl methacrylate)]/[ethyl 2-bromopropionate]/[palladium nanoparticles] = 3.95 × 104:756:1 at 70 °C. The reaction orders concerning palladium nanoparticles, ethyl 2-bromopropionate, and poly (trifluoroethyl methacrylate) were determined to be 0.59, 0.34, and 1.38, respectively. By analyzing a series of characterizations, we verified that the polymerization of poly (trifluoroethyl methacrylate) was initiated by the ethyl 2-bromopropionate residue radicals, which were generated from the interaction between palladium nanoparticles and ethyl 2-bromopropionate. The comparatively large size of the palladium nanoparticles provided a barrier to chain-growing radicals, promoting the synthesis of ultrahigh molecular weight polymers. [ABSTRACT FROM AUTHOR]

Nanotheranostics aims to perform a premature and non-invasive diagnosis combined with therapy focused on the specific place where the disease is by using nanomaterials. To evaluate the ability to penetrate and retain the inorganic nanoparticles (NPs) in the cells, analytical techniques such as Single-Particle ICP-MS (SP-ICP-MS) are required to characterize these NPs. SP-ICP-MS provides not only the size distribution and concentration of NPs but also the concentration of the dissolved elements. In recent years, direct alkaline dilution of blood, serum, and urine is performed in clinical laboratories for routine analysis. This alkaline diluent is named clinical diluent and it is a mixture of ammonia, EDTA, 2-propanol, Triton X100, and purified water. In this work, a methodology to characterize AuNPs in blood and urine samples using SP-ICP-MS has been developed. Samples were directly diluted with clinical diluent before multiquadrupole ICP-MS analysis. The effect of this clinical diluent on the behaviour and stability of AuNPs has been studied. Good stability of AuNPs was observed for both the particle size and particle concentration (<17% difference in 10 days). Moreover, analytical parameters of this method such as linearity, detection limit, accuracy, and precision in blood and urine samples were studied for both the particle size and particle concentration. Linearity was evaluated for particle size (from 10 to 100 nm) and particle concentration (from 5 × 10³ to 1 × 104 NP per mL). Furthermore, recoveries between 88% and 103% for the NP concentration and between 100% and 110% for the nanoparticle size were obtained. Dissolved and gold nanoparticle detection limits have also been estimated. [ABSTRACT FROM AUTHOR]

Highlights In this study, we present a model for predicting the Young's modulus of polymer/nanodiamond (ND) composites, taking into account the interphase properties. The Christensen‐Lo model is adapted and refined to predict the modulus of ND‐based nanocomposites by considering the properties of spherical NDs and their surrounding interphase. The outcomes of the developed model are benchmarked against experimental data, exploring the impact of various parameters, such as ND radius, ND concentration, and interphase properties (thickness and modulus) on the nanocomposite modulus. Findings suggest an inverse correlation between the size of the nanoparticles and the modulus of nanocomposite. Specifically, it is observed that nanoparticles with a minimum radius of 1 nm and a maximum concentration of 5 vol% can increase the nanocomposite modulus by 180%. Additionally, maximum thickness and modulus of the interphase can significantly improve the nanocomposite modulus. The highest interphase thickness of 10 nm and maximum interphase modulus of 100 GPa can grow the modulus of samples by 300%. The predicted influences of all parameters on the nanocomposite modulus validate the accuracy of the developed model. A model for the Young's modulus of polymer nanodiamond (ND) composites is presented. ND radius, ND concentration, and interphase thickness and modulus are considered. The outcomes of the developed model are compared to the experimental data. 5 vol% of the smallest ND (R = 1 nm) increases the nanocomposite modulus by 180%. The thickest and the toughest interphase enhance the nanocomposite modulus by 300%. [ABSTRACT FROM AUTHOR]

For global deployment of proton exchange membrane fuel cells, achieving optimal interaction between the components of the cathode active layer remains challenging. Studies addressing the effect of nanoparticle location (inside vs outside of pores) on performance and durability mostly compare porous and nonporous carbon supports, thus coming short of decoupling nanoparticle locality from carbon support effects. To address the influence of nanoparticle locality on performance and durability, new carbon‐supported electrocatalysts with designed and distinct nanoparticle localities are presented. The developed methodology allows to place Pt nanoparticles preferentially inside or outside of the mesopores of conductive carbon supports from materials under development at Cabot Corporation. Synthesis protocols are tuned to control nanoparticle size, crystallinity, and loading; this way the effect of Pt locality can be studied for two experimental carbon supports in isolation from all other parameters. For one carbon support, Pt active surface area and activity are significantly lower when nanoparticles are placed inside the pores. In contrast, for another, more graphitic carbon support, placing nanoparticles inside or outside of the carbon pores produces no appreciable difference in active surface area and performance rotating disk electrode measurements. Given their carefully tailored structure, these catalysts provide a framework for evaluating locality‐performance‐durability relationships. [ABSTRACT FROM AUTHOR]

Raman spectroscopic data of quenching phases in experiments on the dissolution of Pt in reduced carbonic fluid, containing about 30 mol % of CO, both with and without chlorine at P = 200 MPa and T = 950–1000°C are presented. Water content in the fluid was no more than 4.5 mol %. The only soluble form of Pt determined in the acetone solution of the quenching phases and in the experimental products is platinum carbonyl. Low concentrations of carbonyl (no more than a few ppm) become detectable using Raman spectroscopy due to the SERS effect (Surface-Enhanced Raman Scattering), which is possible in the presence of Pt nanoparticles in the objects under study. Platinum nanoparticles, formed at the decomposition of carbonyls, generates specific photoluminescence (PL) peak approximated by Gaussian with parameters FWHM = 1050–1300 cm–1, kmax = 2050–2100 cm–1 both in acetone solution and experimental samples. The spectra of CO (main band k ≈ 2050 cm–1) adsorbed on Pt nanoparticles supported on glassy carbon, formed during the decomposition of excess CO relative to the CCO buffer, corresponded to nanoparticle sizes of about 2 nm. No convincing evidence of a mixed chloride-carbonyl composition of platinum was found in the spectra, which may reflect the lower thermodynamic stability of these mixed complexes at high P-T parameters. Large concentrations of platinum Pt on carbon (up to 2000–3000 ppm) can be explained by the formation of the Pt-C matrix bond and the weakening of the Pt-CO bond in carbonyls, causing their decomposition. Unusual PL peaks were detected in samples from experiments with chlorine-containing fluids, very reminiscent of the PL background of noble metal nanoparticles and attributed to the effect of carbon nanoparticles. [ABSTRACT FROM AUTHOR]

The synthesis of new compounds and nanoparticles is one of many attempts to circumvent the drug resistance. Albumin nanoparticles are biocompatible drug carriers with an ability to incorporate drugs without modifications. 10H-2,7-diazphenothiazine (2,7-DAPT) is a newly phenothiazine derivative with an anticancer, immunomodulatory and anti-inflammatory activity with a low cytotoxicity toward normal splenocytes at the same time. Up to now, no administration route for 2,7-DAPT has been proposed, so the novelty of the study is synthesis of nanoparticles containing an active ingredient not yet used in the clinic. The aim of the study was to encapsulate 2,7-DAPT into bovine serum albumin (BSA) nanoparticles by desolvation method. This study was supplemented with spectroscopic studies of 2,7-DAPT, size and morphology measurements as well as release analysis at pH 7.4 and 5.6. 2,7-DAPT is a compound with high stability in solution and an ability to absorb at UV-Vis range. Based on the results of scanning electron microscopy, nanoparticles size oscillates around the value of 204 nm. The release of 2,7- DAPT from the nanoparticles was characterized by different mechanisms of release, which were dependent on the pH of the release buffer. The above results indicate the potential usefulness of the obtained nanoparticles. Due to the lack of studies of nanoparticles containing this substance, more detailed future analyses are required. [ABSTRACT FROM AUTHOR]

High entropy or multi-principles component oxides as a new class of materials have been widely investigated for various applications due to their unique properties and multi-functionalities in recent years. In this study, a high entropy transparent ceramics ((Gd 0.2 Tb 0.2 Y 0.2 Lu 0.2 Yb 0.2) 3 Al 5 O 12) has been fabricated by spark plasma sintering (SPS) using co-precipitation synthesized powders. The powder preparation process was studied by TAG-DSC and FTIR. The phase structure, morphology, and element distribution of the obtained powder and ceramic samples are explored by XRD, SEM, and EDS mapping. It shows that the high entropy oxide (HEO) ceramic powder has a pure garnet phase, nanoparticle size, and homogenous elements distribution. The sintered ceramic exhibits the highest in-line transmittance in the visible and IR range of approximately 52 % at 700 nm and 74 % at 3.6 μm, respectively. In addition, characteristic optical properties of the final ceramics were demonstrated by photoluminescence spectroscopy. This work indicated that high-entropy garnet transparent ceramics with multi-wavelength emissions will provide more possibilities for multifunctional optical applications in the future. [ABSTRACT FROM AUTHOR]