Journal of Nanoparticle Research最新文献

Ag nanoparticles can easily be deposited on semiconductors through the photocatalytic growth process to yield directly attached metal nanoparticles on the material surface. However, the growth behavior and kinetics of the photocatalytic growth require further investigations to guide controlled preparation. Herein, the behavior and kinetics of photocatalytic growth Ag nanoparticles on sol–gel TiO₂ films were first explored by in situ UV–Vis-NIR extinction spectroscopy and scanning electron microscopy. The results suggested average size evolution of Ag NPs varied according to d³ ∝ t law, and Ostwald ripening mechanism dominated by the growth process of Ag NPs. The in situ UV–Vis-NIR extinction spectra highlighted the presence of a critical concentration of Ag⁺ ion at a given irradiation intensity. The critical AgNO₃ concentration C(I) gradually rose with the irradiation intensity. The values of C(I) at 1, 1.6, and 5.3 mW/cm² irradiations were approximately 400, 800, and 1600 mg/L, respectively. For Ag⁺ ion levels below the critical concentration, the growth of Ag NPs was controlled by Ag⁺ diffusion-limited growth. For Ag⁺ ion levels above the critical concentration, the growth of Ag NPs was controlled by photo-induced carrier diffusion-limited growth. Overall, the clarified kinetics of photocatalytic growth of Ag nanoparticles on sol–gel TiO₂ films would help prepare customized noble metal nanoparticles by photocatalytic growth or other similar methods like electrochemical deposition and galvanic cell replacement.

In this work, a simple, inexpensive, and environmentally benign method has been developed to synthesize luminescent sulfur and nitrogen co-doped carbon quantum dots (S,N-CQDs) utilizing DL-DOPA, o-phenylenediamine, and sulfuric acid via microwave-assisted synthesis. The optical characteristics of the as-fabricated S,N-CQDs were analyzed using various spectroscopic techniques, including UV–Vis, fluorescence, and TCSPC techniques. For structural characterization, a comprehensive approach was employed, involving HR TEM, FE-SEM coupled with EDX, and XRD. Additionally, the functional groups and surface composition were identified through XPS, FTIR, and Raman spectroscopy. The thermal stability of the as-fabricated S,N-CQDs was assessed using thermogravimetric analysis (TGA), confirming their robust structural properties. The synthesized S,N-CQDs, with an average size of 9.3 nm, demonstrated impressive thermal stability, remarkable biocompatibility, and a high quantum yield of 17%, along with outstanding optical and chemical properties, and promising biological activities. They demonstrated excellent free radical scavenging activity (EC50: 61.26 µg/mL) and effective antimicrobial properties. Moreover, the as-fabricated S,N-CQDs exhibited outstanding selectivity and sensitivity toward Fe³⁺ ions, with a limit of detection (LOD) of 0.15 µM. Their ability to distinguish Fe³⁺ from other metal ions confirms their potential as fluorescent probes for Fe³⁺ detection in environmental and biological samples.

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Phosphorus (P) is a crucial macronutrient for plant growth, root development, and yield. Commercial P fertilizers have low efficiency of delivery and utilization and are lost from plant root zones by either low availability or leaching or surface runoff that leads to environmental damage. This review investigates how nano P fertilizers (NPFs) can overcome the current inefficiencies of conventional formulations and, thus, enhance plant yield while minimizing negative environmental impacts. NPFs have significant potential for augmenting plant germination by more effectively penetrating seed coatings and facilitating greater water and nutrient uptake. The nanoscale nature of NPF also uniquely facilitates greater P absorption by roots, which in turn enhances chlorophyll synthesis, improves light absorption, and optimizes electron transport efficiency—key factors in boosting plant photosynthesis. Additionally, it stimulates overall physiological processes (e.g., secondary metabolite production, root exudation), increases antioxidant enzyme activities, and enhances plant yield. NPFs can also minimize the accumulation of toxic elements by several mechanisms, including controlling contaminant bioavailability in soil by enhancing competing plant essential element (e.g., P, Ca) uptake. Moreover, NPFs also mediate soil pH, which has important implications for soil biogeochemistry in low-pH agricultural areas. Soil microbiomes and associated processes will often improve with NPF application relative to conventional P formulations. Although great potential has been demonstrated, a mechanistic understanding of certain aspects of NPF activity remains incomplete, including impacts across diverse crop species, environmental conditions, and soil types. However, NPFs offer great potential as an important tool in the transformation of conventional agriculture, simultaneously lessening the usage of finite P resources, reducing the environmental footprint of agriculture, and improving future food security.

Graphical Abstract

The structural and electronic properties of neutral and charged Mg and ZnMg clusters, for different sizes, have been investigated in order to know how the reactivity of pure magnesium clusters will be influenced by the substitution of a single atom of zinc, and how these clusters interact with the oxygen atom. The calculations have been performed in the framework of the density functional theory in the generalized gradient approximation for the exchange and correlation. The results show that doping with a single Zn impurity is enough to change the structure of the host magnesium cluster and modify the bonding pattern making the structures more stable. The calculated adiabatic electron affinity and vertical detachment energy of pure magnesium clusters show good agreement with the available experimental data and indicate that Zn doping enhances their stability during the reduction process. The adsorption of Zn atom significantly affects the stability of the magnesium clusters during the oxidation process. The calculated results of the adsorption energy of oxygen show that, in general, the reactivity of oxygen atom decreases when the cluster size increase, which impact their anticorrosive properties making them more suitable for generating protective coating layers.

The study investigated processes of bimetallic copper/silver nanoparticle formation in aqueous media using two reducing agents: sodium borohydride and ascorbic acid. Adding these reducing agents in sequence allows the synthesis of bimetallic nanoparticles at room temperature. The influence of stabilizing agents such as sodium dodecyl sulfate, cetyltrimethylammonium bromide, and oleic acid and their combinations on the composition of nanoparticles in suspensions and the stability of suspensions was examined. When using a combination of oleic acid and sodium dodecyl sulfate, bimetallic copper/silver nanoparticles with a preset composition of 4:1 were formed. These nanosized systems remain stable for at least 3 months. The proposed synthetic method allows the fabrication of copper/silver nanoparticles ranging in size from 30 to 40 nm. The studied nanoparticles were shown to completely inhibit the colony growth of E. coli and S. aureus test strains on dense nutrient media when diluted to 10%, with exposure times of 3 and 5 h.

Carbon dots (CDs) have been obtained by laser ablation of charcoal in a biocompatible liquid and deposited as a thin film on a silicon substrate. A ns-pulsed Nd:YAG laser, operating at 1064 nm of wavelength, irradiates for times up to 3 h the solid carbon target placed into a phosphate-buffered saline (PBS) solution and distilled water, to prepare the CDs dispersion. The prepared thin film on silicon, under a UV lamp at 365 nm in air generates fluorescence in the visible region, with a band around 470 nm, with a blue color. Further investigations concern the thin-film irradiation using 0.8–3.0 MeV protons with 3 nA current in a vacuum, showing also fluorescence in the visible region, from about 400 up to 700 nm, as recorded by a suitable optical spectrometer. The practical applications of CDs are also presented especially in the biomedical field and in the dosimetry ambit, where they can be employed for bioimaging, diagnostics, and therapy.

The removal of Ni²⁺ ions from the effluent of the paper mill was accomplished by using magnesium ferrite nanoparticles. The nanoparticles were produced through a sol–gel process at low temperatures. Experimental factors were meticulously optimized to enhance the adsorption process. Optimal conditions were determined to be 1.0 mL of buffer solution with a pH of 8.0, 100 mg of nano-sorbent, and mixing for 30 min. When these conditions were put to test, the removal efficiency was enhanced to ≥ 98.4%. Additionally, it was discovered that the nanoparticles exhibit exceptional reusability upon regeneration after the first use. The investigation of adsorption equilibrium was conducted utilizing the Langmuir, Freundlich, and Sips models. The Sips isotherm demonstrated the strongest correlation with the experimental results, as indicated by the coefficient of determination (R²) of 0.9976 while the reaction order was estimated as 1.61 by the kinetic model.

Lung cancer is the leading cause of cancer-related deaths, worldwide. To date, various strategies have been developed and examined for treating lung cancer. The era of nanotechnology has opened a new avenue for designing advanced nanoparticulate systems for single or multiple delivery of chemotherapeutics. Despite the promising synergism between these systems, some challenges still remain. Therefore, various combination therapies based on nanostructures are developed to alleviate the drawbacks of conventional systems. These combinations may or may not have synergistic therapeutic effects. It has been observed that using combination therapies could result in a higher rate of response to treatment when compared with each modality alone. While these nanotechnological routes demonstrate promising therapeutic potentials, still some challenges such as manufacturing scalability, stability under physiological conditions, and ability to clinical translation remain unsolved. These therapies not only moderate the symptoms of the disease but also are useful for cure. It is worth noting that performing various combinations of therapies based on the symptoms, stage, and type of lung cancer could have better therapeutic outcomes than single therapies. Therefore, these kinds of treatments are proposed for clinical lung cancer treatment.

Currently, iron oxide nanoparticles around 25–30 nm in diameter are the standard magnetic tracers used for magnetic particle imaging (MPI) applications. Compared to iron oxide nanoparticles, less research has been performed in creating pure iron nanoparticles for MPI applications. Previous studies have created iron core–iron oxide shell nanoparticles around 15 nm in diameter, but in order to achieve optimal MPI signal similar to iron oxides, larger diameters around 20 nm are needed. However, due to the strong magnetic characteristics of pure iron, synthesizing pure iron nanoparticles above 15 nm in diameter can be challenging due to the high risk of agglomeration. Therefore, an investigation into creating 20-nm-sized iron nanoparticles was performed utilizing potential surfactants that might prevent agglomeration. A thermal decomposition of iron pentacarbonyl was performed with different surfactants including decylamine (DA), dodecylamine (DDA), hexadecylamine (HDA), octadecylamine (ODA), and dioctyldecylamine (DODA) to determine potential differences in size or composition. All surfactants possessed a linear structure and only varied in alkyl-chain length. From the results, it was found that longer alkyl-chain length surfactants assisted in creating larger iron nanoparticle sizes.