Journal of Nanoparticle Research最新文献

Sodium sulphide-doped graphene oxide (Na₂S-GO) nanocomposites with varying doping concentrations of sodium sulphide were synthesized and systematically examined for their morphological, structural, dielectric, and electrical conductivity properties. Graphene oxide (GO) required for Na₂S-GO synthesis has been produced by employing a modified Hummers technique. Scanning electron microscopy (SEM) analysis revealed a stacked flake-like morphology characteristic of GO. When coupled with the Energy Dispersive X-ray Analysis (EDAX), it quantified the constituent elements and verified successful doping. X-ray diffraction (XRD) analysis probed the structural properties of the nanocomposites; it confirmed reduction of graphite to GO, with the doped samples exhibiting smaller crystallite sizes than pure GO. Impedance spectroscopy, dielectric studies, and AC conductivity measurements indicated a non-Debye type of relaxation (Cole–Cole) and existence of hopping conduction dynamics. Arrhenius conductivity analysis demonstrated an increase in activation energy with doping. DC analysis indicated that the Mott variable range hopping (VRH) mechanism dominates charge transport in Na₂S-GO nanocomposites.

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Transforming coal tar pitch (CTP) into cleaner fuels and high-value chemicals has attracted considerable attention, largely due to its intricate molecular architecture, high content of polycyclic aromatic hydrocarbons (PAHs), and the environmental concerns associated with its direct use. In this work, we designed a mesoporous zeolite Socony Mobil-5 (ZSM-5)/silicoaluminophosphate-11 (SAPO-11) via hydrothermal synthesis and subsequently introduced Ni nanoparticles (NNPs) using a deposition-precipitation technique, yielding Ni/(ZSM-5/SAPO-11) catalyst with a well-developed hierarchical pore system. Comprehensive structural analyses—employing X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), NH₃ temperature-programmed desorption (NH₃-TPD), pyridine infrared (Py-IR), and X-ray photoelectron spectroscopy (XPS)—revealed that the Ni was highly dispersed throughout the zeolitic framework. To probe catalytic performance under various conditions, anthracene was selected as a model compound. Remarkably, complete hydrogenation of anthracene was achieved after just 1 h of reaction in n-hexane at 160 °C under an initial hydrogen pressure (IHP) of 4 MPa, highlighting the catalyst’s exceptional activity under relatively mild catalytic hydroconversion (CHC) conditions. Furthermore, when applied to the extractable portion (EP) of CTP under the same temperature and pressure for 18 h, the catalyst facilitated nearly full conversion to cycloalkanes (95.6%), oxygen-containing organic compounds (OCOCs, 4.2%), and minor amounts of chain alkanes (CAs, 0.2%). These results collectively point to the pivotal role of both the tailored pore architecture and the uniform distribution of NNPs, which synergistically enhance molecular diffusion, active site accessibility, and the efficiency of hydrocracking and heteroatoms (HAs) removal processes.

Osteoporosis can be categorized into primary and secondary types, with glucocorticoid-induced osteoporosis (GIOP) being the most common form of secondary osteoporosis and the third most prevalent overall. This study explores the anti-osteoporosis effects of zinc oxide nanoparticles (ZnO NPs) and nano-hydroxyapatite (HA NPs) in a rat model of dexamethasone (DEX)-induced osteoporosis. Nanoparticle characterization was conducted using various techniques to evaluate size, shape, and chemical composition. A total of 48 adult female Swiss albino rats were divided into six groups (n = 8). Osteoporosis was induced in Groups II–VI with DEX (7 mg/kg, IM) weekly for 5 weeks. Subsequently, treatments were administered for 3 months: Group I (negative control), Group II (DEX-induced OP), Group III (alendronate (1 mg/kg) weekly), Group IV (ZnO NPs (0.50 mg/kg) monthly), Group V (HA NPs (8 mg/kg) monthly), and Group VI (combination (ZnO NPs/HA NPs) IV monthly). Serum samples were analyzed for bone metabolism markers—including cross-linked C-telopeptide of type I collagen (CTX-1), tartrate-resistant acid phosphatase 5b (TRACP-5b), alkaline phosphatase (ALP), calcium (Ca²⁺), and phosphorus (P). Molecular analysis and histopathological assessment of femurs were performed. Results indicated that treatment with ZnO NPs or HA NPs significantly up-regulated Runt-related transcription factor-2 (RUNX-2) expression; decreased serum CTX-1, TRACP-5b, and ALP levels; and increased Ca²⁺ and P levels, thereby promoting bone mineralization and ameliorating DEX-induced histological alterations in bone tissues. Notably, the combination treatment of ZnO NPs and HA NPs exhibited superior effects due to synergistic actions. This study highlights the promising anti-osteoporosis potential of ZnO NPs and HA NPs, both individually and in combination, for the treatment of dexamethasone-induced osteoporosis.

There is a growing need for multifunctional biomaterials to serve both structural stabilization and biological function in bone regeneration. In this work, we developed hydroxyapatite–gelatin composites that combine dual-drug delivery with bioactivity and cytocompatibility. Macroporous composites were fabricated using a foam-templated precipitation route, and dual drugs were loaded (rifampicin, an antimicrobial, and indomethacin, an anti-inflammatory). Release kinetics exhibited a triphasic release profile with ~ 65–70% release taking place in the first 96 h, followed by sustained release until 240 h. The initial release kinetics showed the drug was released according to the Higuchi model; the profile shifted towards diffusion–swelling as confirmed by the Korsmeyer–Peppas fitting. When immersed in simulated body fluid in vitro, apatite was uniformly deposited within 7 days, indicating mineralization capacity was preserved. Cytocompatibility studies using MG-63 osteoblast-like cells showed 90% viability or greater for all extract concentrations, exceeding ISO 10993–5 criteria. These results demonstrate the composites as a multifunctional bone filler platform, enabling localized delivery of antimicrobial and anti-inflammatory drugs, bioactivity, and cytocompatibility.

The adsorption behavior of 2-(4-oxo-2-thioxothiazolidin-3-yl)-N-(p-tolyl)acetamide (OTA) on silver nanoparticles was studied using surface enhanced Raman scattering (SERS) and density functional theory (DFT). The presence of various inactive Raman modes in SERS is due to polarizability variations in the presence of metal. Negative adsorption energy shows strong bonding between silver and OTA. Structural characteristics represent charge transfer of the metal cluster that underwent bonding with OTA. The hardness and chemical potential of OTA are 1.6527 and −4.4407 eV, while these in OTA1 (C=O near to Ag₆) are 1.1789 and −3.7449 eV, and the reduction in these values shows a strong shared interaction with OTA and Ag. The υC=O are observed in SERS at all concentrations and show up and down changes in frequencies, giving interaction with Ag and orientation changes with concentration changes. Since OTA is an acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitor, docking with 1GQR and 6ASM gives binding affinities of −8.5 and −7.8 kcal mol⁻¹. Molecular dynamics (MD) simulations indicate that docked OTA remained stable, maintained by H-bonds. When OTA was near Ag₆, changes were observed in electron density at several places.

This study conducts a comprehensive first-principles density functional theory analysis on pristine PtS₂ monolayers and those doped with O, Se, Te, Si, P, and Cl atoms. Geometry optimization reveals that different doping induces ordered changes in bond lengths and lattice parameters. Electronic structure calculations indicate that doping effectively tunes the bandgap from semiconducting to near-metallic states, inducing pronounced orbital hybridization at the Fermi level. Optical property analysis (real and imaginary dielectric functions, absorption coefficients, and reflectivity) reveals the differences in the response of doped systems in the UV, VIS, and NIR wavelength bands. Furthermore, the O- and P-doped systems were investigated systematically. The bandgap and main absorption/reflection peaks undergo reversible redshift and blueshift when bi-directional strain is applied to the O- and P-doped systems. The study provides a comprehensive and compact theoretical basis for the applications of tunable photovoltaic devices, IR detectors, and flexible strain sensors based on PtS₂.

Superparamagnetic iron oxide nanoparticles (SPIONs) are promising in cancer nanomedicine due to their magnetic responsiveness and biocompatibility, yet their clinical use is hindered by instability, oxidation, and lack of active targeting. Here, we report a multi-stimuli-responsive nanocarrier that integrates magnetic responsiveness from the SPION core, folic acid–mediated active targeting, and pH-sensitive release. Oleic acid (OA)–stabilized SPIONs (OCION) were coated with a Brij–folic acid (BF) conjugate, and quercetin (QCT), a poorly soluble anticancer drug, was encapsulated in the hybrid lipid bilayer (HLB). The BF to OCION ratio was optimized, and the 6:1 formulation yielded uniform, monodisperse nanoparticles OCION@BF with excellent colloidal stability for 30 days and preserved superparamagnetic properties. The optimized OCION@BF achieved 95% encapsulation efficiency and enabled sustained, pH-responsive QCT release, with faster liberation under acidic conditions. Biological assays confirmed that blank OCION@BF was non-toxic, while QCT@OCION@BF significantly improved anticancer efficacy against MCF-7 cells, showing a ~ 2.4-fold lower IC₅₀ than free QCT. Collectively, OCION@BF combines exogenous (magnetic), endogenous (folate-targeting), and microenvironmental (pH-responsive) stimuli responsiveness, representing a versatile platform for efficient delivery of poorly soluble drugs and a promising candidate for targeted cancer therapy.

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Ballistic aggregates (BAs) have long been used in astrophysics to model interstellar dust, particularly for analyzing their light scattering and absorption characteristics. In this work, we extend the application of BA structures into the plasmonic domain by investigating their optical response at the nanoscale. Using the discrete dipole approximation (DDA), we numerically simulate the extinction and absorption behavior of 50 nm radius metal nanoparticles (Al, Ag, Au) arranged in BA, BAM1, and BAM2 configurations. Our results confirm that the optical properties of these clusters are strongly influenced by porosity, number of monomers, and the refractive index of the embedding medium. Notably, we identify a transition wavelength, below which extinction increases with porosity, while above it, the trend reverses. We also observe a redshift in surface plasmon resonance (SPR) with decreasing porosity and increasing cluster size, offering broad tunability of the extinction spectrum. The near-field analysis further reveals significant field enhancement due to interparticle coupling. These findings suggest that nanoscale BA-type clusters could serve as viable candidates for plasmon-enhanced light absorption in photovoltaic applications.

The rapid control of opportunistic pathogens—through both their detection and elimination—is crucial to mitigate health risks, especially for immunocompromised individuals. In this study, silver nanoparticles (AgNPs) were synthesized via a simple and environmentally friendly approach, using ascorbic acid reduction under medical steam sterilizer conditions, and evaluated as a dual-function colloidal platform that integrates antimicrobial activity and surface-enhanced Raman scattering (SERS)-based pathogen identification. Structural characterization using scanning electron microscopy, zeta potential, UV–Vis spectroscopy, and X-ray diffraction confirmed uniform morphology, high colloidal stability, and crystallinity. The AgNP substrates provided robust and reproducible SERS signals, achieving an analytical enhancement factor of approximately 10⁶ at concentrations down to 1 nM, with sample-to-sample variability below 5%. The antimicrobial assays demonstrated rapid biocidal activity, with > 99% (R > 2) of Escherichia coli, Staphylococcus aureus, and Candida albicans eliminated within 1 h, and significant bactericidal efficacy (R > 6) maintained over 48 h. Importantly, the controlled antimicrobial interaction facilitated the release of intracellular components, yielding more consistent and distinctive spectral profiles that enhanced species-level discrimination. Principal component analysis (PCA) revealed clear separation among pathogen-specific spectral clusters, while a linear support vector machine (SVM) classifier achieved 95.7% accuracy, confirming strong discriminative capability. Overall, this study serves as a proof of concept for a dual-function colloidal AgNP platform, synthesized via an accessible autoclave-assisted green approach, that combines antimicrobial action with SERS-based pathogen identification in a simple and reproducible format.

Alzheimer’s disease (AD) therapies remain limited by poor blood–brain barrier (BBB) penetration and modest cognitive recovery. This study aimed to develop and evaluate transferrin-conjugated S-adenosylmethionine-loaded citric acid-stabilized superparamagnetic iron oxide nanoparticles (Tf-SAMe-CA-SPIONs) as a targeted nanoplatform for brain delivery. SPIONs were synthesised by co-precipitation and optimised using a design of experiments approach. The formulation was characterised for physicochemical, magnetic, and structural attributes, and its BBB permeability and neuroprotective efficacy were assessed using in vitro and zebrafish AD models. The optimised SPIONs displayed hydrodynamic diameters of 58–71 nm (PDI < 0.33). Following citric acid stabilisation, the particle size increased to 111.3 nm (PDI 0.347, zeta potential –20.08 mV), while transferrin–SAMe conjugation further enlarged the particles to around 196.4 nm with a zeta potential of –28.28 mV. XRD confirmed the magnetite spinel crystalline structure, and VSM analysis verified their superparamagnetic behaviour with a saturation magnetisation (Ms) of 52 emu/g. The formulation demonstrated a high drug-loading efficiency of 72% and exhibited transferrin receptor–mediated cellular uptake in vitro. In vivo, treatment with the formulation led to significant cognitive enhancement in zebrafish, as evidenced by increased correct entries, reduced latency, and prolonged reward chamber occupancy, outperforming currently available formulations. Tf–SAMe–CA–SPIONs demonstrated excellent stability, efficient brain-targeted delivery, and marked improvement in cognitive function. By integrating targeted delivery, magnetic responsiveness, and neuroprotective effects, this multifunctional nanoplatform offers a promising theranostic strategy for the treatment and management of Alzheimer’s disease.

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