Search Results (706)

This study investigated the biosynthesis of magnetite nanoparticles mediated by chia mucilage (CM-Fe₃O₄ NPs) and their application in the co-encapsulation of Lactobacillus rhamnosus GG (LGG) using spray drying. CM-Fe₃O₄ NPs were synthesized by combining CM extract with iron salts, in which hydroxyl and carbonyl groups of CM acted as natural ligands for Fe²⁺/Fe³⁺ ions. A response surface design was applied to optimize synthesis parameters, focusing on size distribution and zeta potential, and confirming the influence of pH on colloidal stability. Characterization by FE-SEM, DLS, XRD, UV-Vis, and FTIR revealed spherical particles with an inorganic core (50–300 nm) and a hydrated organic coating (600–900 nm), consistent with a spinel structure functionalized by CM. Spray-drying encapsulation tests showed that incorporating CM-Fe₃O₄ NPs did not compromise bacterial viability, maintaining optimal moisture content and survival. Growth curves and confocal microscopy corroborated the physiological compatibility of the nanoparticles, with no alterations in LGG morphology or growth dynamics. Under simulated gastrointestinal conditions, co-encapsulated microcapsules exhibited slightly improved survival in the gastric phase and significantly greater viability in the initial intestinal phase. These results suggest that CM-Fe₃O₄ NPs modulate matrix degradation and promote controlled release, ensuring therapeutic concentrations of LGG in the intestine. Overall, the CM-Fe₃O₄ nanocomposite system integrates the protective properties of biopolymers with the functional advantages of iron nanoparticles, offering dual functionality: probiotic stabilization and potential iron supplementation. This innovative, food-grade approach supports the development of next-generation functional foods with combined therapeutic and nutritional benefits. Full article

(1) Background: Overuse of chemical nitrogen fertilizers drives the need for biological alternatives. Azotobacter chroococcum is a promising free-living nitrogen-fixing bacterium, but its efficiency needs improvement. This study investigated how Fe₃O₄ nanoparticles (Fe₃O₄ NPs) and molybdenum trioxide nanoparticles (n-MoO₃) affect A. chroococcum growth and nitrogen fixation, and tested the modified inoculants on Glycine max (legume) and Nicotiana benthamiana (non-legume); (2) Methods: In vitro tests measured bacterial growth, viable counts (CFU), nitrogenase activity, and nitrogen metabolites (total N, NO₃⁻-N, NH₄⁺-N) under 0–100 ng·mL⁻¹ Fe₃O₄ NPs or n-MoO₃. Pot experiments then tested modified inoculants on Glycine max and N. benthamiana for biomass and N, P, K uptake; (3) Results: Both nanomaterials showed low-dose stimulation and high-dose inhibition. At 10 ng·mL⁻¹, bacterial growth (OD₆₀₀ up ~1.2×) and nitrogenase activity (up >90%) rose significantly (p < 0.05–0.001), along with higher total N, NO₃⁻-N, and NH₄⁺-N. In pots, 10 ng·mL⁻¹ modified inoculant improved all Glycine max traits and nutrient uptake (p < 0.05). For N. benthamiana, biomass peaked at 20 ng·mL⁻¹, while stem and root growth did best at 10 ng·mL⁻¹. At 100 ng·mL⁻¹, effects weakened or vanished. A “metabolic remodeling–rhizosphere transformation–systemic response” mechanism is proposed; (4) Conclusions: Low concentrations (10–20 ng·mL⁻¹) of Fe₃O₄ NPs and n-MoO₃ can effectively boost the nitrogen-fixing function and growth-promoting effect of A. chroococcum inoculant, showing good potential for use on both legume and non-legume crops. This study provides a theoretical basis and technical reference for developing efficient, broad-spectrum nanomaterial-microbe composite inoculants. Full article

Background/Objectives: Jaw osteomyelitis (OM) is a refractory purulent inflammation caused by bacterial infection, characterized by persistent infection, excessive bone resorption, and resultant bone defects. Currently, mainstream therapies for jaw OM struggle to eradicate persistent infections, avoid antibiotic resistance, and repair infected bone defects, posing a critical challenge in clinical practice. Methods: Herein, the Fe₃O₄@ZIF-8 core–shell nanoparticles (NPs) platform designed for jaw OM treatment consisted of Fe₃O₄ as the core and zeolitic imidazolate framework-8 (ZIF-8) as the shell. Results: The core–shell platform not only integrated the pH-responsive degradation capability of ZIF-8 but also retained the superparamagnetism of Fe₃O₄ NPs. In the acidic, infectious microenvironment, Fe₃O₄@ZIF-8 NPs underwent continuous degradation, releasing Zn²⁺, thereby conferring potent antibacterial activity. The specific antibacterial mechanism of the nanoparticles lies in the fact that high concentrations of Zn²⁺ directly disrupted bacterial cell membranes and inhibited the bacterial heat shock response. This dysregulates bacterial proteostasis, rendering the bacteria more sensitive to external adverse stresses, ultimately leading to bacterial death. With ZIF-8 framework degradation, the encapsulated Fe₃O₄ NPs were released. Under static magnetic field (SMF) synergy, Fe₃O₄ NPs collaborated with Zn²⁺ to promote bone regeneration and repair infected bone defects in jaw OM lesions. Conclusions: As a multifunctional core–shell platform, Fe₃O₄@ZIF-8 NPs meet the dual clinical needs of antibiosis and osteogenesis, offering a promising translational strategy for jaw OM therapy. Full article

This study presents a straightforward process for producing a hybrid ternary composite of silver nanoparticles (Ag NPs), small graphene oxide (s-GO), and zirconia (ZrO₂) and its use as an electrode material for electrochemical sensing. The physico-chemical properties of the ternary composite were analyzed by means of field emission scanning electron microscopy (FE-SEM), ultraviolet-visible (UV-vis) and FTIR spectroscopy, X-ray Photoelectron Spectrometry (XPS) and contact angle (CA) measurements. The synthesized hybrid nanomaterial was employed as an electrode modifier in the fabrication of a modified screen-printed carbon electrode (SPCE) and used for the simultaneous electrochemical sensing of key environmental pollutants such as hydroquinone (HQ) and catechol (CAT). The developed sensor exhibited linearity in the range of 0–100 µM for both HQ and CAT, with sensitivity values of 2640 µA·mM⁻¹·cm⁻² for HQ and 5120 µA·mM⁻¹·cm⁻² for CAT. The limits of detection (LOD) were 1.5 µM for HQ and 0.72 µM for CAT, respectively. The synergistic enhancement of electron transfer kinetics, the increased electroactive surface area, the strong anti-interference capability, and excellent reproducibility and stability establish these modified electrodes as promising candidates for environmental monitoring and real sample analysis. Full article

The conversion of lignocellulosic biomass (LCB) into biofuels is hindered by its inherent resistance and the drawbacks of conventional pretreatment, which include high cost, intensive energy use, and inhibitor formation. Here, we present a novel, one-pot bioconversion process that bypasses pretreatment by integrating cerium-doped iron oxide nanoparticles (CeFeO₄NPs) with a specialized enzyme system. The system utilizes enzyme supernatant from Penicillium janthinellum mutant EU-30, a strain developed via chemical–physical mutagenesis, which exhibits stable hemicellulase activity and a 25–30% increase in cellulase activity. The integrated approach effectively saccharified raw sugarcane bagasse (SB) within 24 h, generating the highest yields of 12.8 ± 0.5 g/L glucose and 11.54 ± 0.5 g/L xylose compared to other substrates tested. Subsequent fermentation with Saccharomyces cerevisiae yielded 13.47 g/L ethanol (1.21 g/L/h productivity) and demonstrated concurrent consumption of both hexose and pentose sugars. We propose that residual CeFe₃O₄NPs in the hydrolysate mitigate carbon catabolite inhibition, thereby increasing xylose utilization. This was attributed to the residual CeFe₃O₄NPs in the hydrolysate, which are thought to upregulate xylose-metabolism-related genes in S. cerevisiae, thereby alleviating carbon catabolite inhibition. This method offers a streamlined, economical, and sustainable platform for producing carbon-neutral bioethanol from agricultural waste, eliminating costly pretreatment and simplifying downstream processing. Full article

This paper presents a comprehensive investigation into the synthesis, morphological characteristics, electrical conductivity, dielectric behavior, and electrocatalytic activity of perovskite-structured iron manganite (FeMnO₃), with a specific focus on its performance in the hydrogen evolution reaction (HER). FeMnO₃(FMO) nanoparticles (NPs) were synthesized using a sol–gel-type Pechini method and characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and field-emission scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (FESEM-EDS). XRD analysis confirmed the formation of a crystalline structure with cubic symmetry assigned to the Ia-3 space group, with an average crystallite size of 52.47 nm. FESEM images revealed a relatively uniform morphology with an average particle diameter of 55.84 nm. The redox and oxidation states of Fe and Mn can be studied by temperature-programmed oxidation (TPO-O₂) in order to understand oxygen uptake and metal oxidation processes occurring within the FMO lattice. The dielectric constant, dielectric loss, electric modulus and electrical conductivity were calculated as a function of frequency and temperature using a Novocontrol Alpha-A broadband dielectric spectrometer (Novocontrol system) coupled with the LCR-800 precision meter. The dielectric data reveal that the FMO has semiconducting behavior with dominant charge- or ionic-relaxation processes. The electrocatalytic activity toward the HER was evaluated using linear sweep voltammetry (LSV), with the working electrode modified by an FMO catalyst ink. The material exhibited significant catalytic activity within the HER potential range, and an increase in the number of cycles led to stabilized current and enhanced hydrogen evolution. These results highlight the stability of FeMnO₃ for hydrogen generation. Full article

Given the increasing environmental degradation, this study investigates advanced zinc oxide (ZnO)-based materials for the mineralization of toxic compounds through the combined action of photo- and piezocatalysis. Two complementary strategies were employed to enhance catalytic efficiency. First, ZnO_1−xN_x thin films were deposited by reactive high-power impulse magnetron sputtering (R-HiPIMS) to reduce the band gap energy. Second, flower-like ZnO nanostructures were synthesized using the pulsed thermionic vacuum arc (p-TVA) technique to increase the specific surface area. Both systems were further modified by decoration with Ag₂O nanoparticles to improve charge separation. The R-HiPIMS technique offers significant advantages in terms of precise control over processing parameters, enabling accurate tuning of film properties, including microstructure, chemical composition, and electronic structure. However, films produced via R-HiPIMS generally exhibit lower photo-piezocatalytic activity compared to nanostructured counterparts, primarily due to their comparatively reduced effective surface area and limited charge separation efficiency. In contrast, the p-TVA technique enables the synthesis of nanostructured thin films with substantially enhanced photo-piezocatalytic performance. This improvement is attributed to the increased effective surface area and the promotion of more efficient electron–hole pair separation. The materials were comprehensively characterized in terms of optical properties (UV–Vis spectroscopy), chemical composition and bonding (XPS), crystalline structure (XRD), surface morphology (FE-SEM), and photo-piezocatalytic performance. Catalytic activity was evaluated via the degradation of methylene blue (MB) under visible light irradiation and mechanical vibrations. Nitrogen incorporation in ZnO_1−xN_x thin films led to an increase in photocatalytic efficiency from 20% to 28.7%, while the simultaneous application of light and mechanical stimulation increased efficiency to approximately 50%. Under identical irradiation conditions, Ag₂O-decorated ZnO and Ag₂O-decorated ZnO_1−xN_x exhibited photo-degradation reaction rate constants up to 65% higher than bare counterparts, attributed to reduced electron–hole recombination. ZnO nanostructures achieved degradation efficiencies of 59%, rising to 88.3% with Ag₂O decoration under solar illumination for 120 min. When combined with mechanical vibrations, after 60 min, the degradation efficiencies reached 93% for ZnO and 98% for Ag₂O/ZnO systems. A photodegradation mechanism of Ag₂O NPs-decorated ZnO heterostructures was proposed. Full article

Oxaliplatin (OXA) is a chemotherapeutic agent that suffers from poor pharmacokinetics and off-target toxicity. To enable controlled OXA release, we engineered a multi-functional iron oxide nanoparticle (IONPs) drug delivery system, based on pH-responsive mesoporous Fe₃O₄ (Fe₃O₄@MSN-NH₂) nanoparticles (NPs), conjugated with folic acid (FA) for receptor-mediated targeting and guided by a magnetic robot platform (MRP) under simulated physiologically relevant dynamic circulation/flow system. For FA-conjugated NPs (Fe₃O₄@MSN-NH₂/FA), ~29.73% OXA loading was achieved compared to ~10.3% in controls (Fe₃O₄@MSN-NH₂/OXA), quantified by ICP-OES. Under dynamic circulation flow over 48 h, MRP enhanced pH-responsive OXA release (quantified by HPLC-UV), reaching ~92% and 88% (Fe₃O₄@MSN-NH₂/OXA and Fe₃O₄@MSN-NH₂/FA, respectively) at pH 5, versus 47% and 40% (Fe₃O₄@MSN-NH₂/OXA and Fe₃O₄@MSN-NH₂/FA, respectively) without MRP, demonstrating precise control in acidic tumor-mimicking conditions. MRI relaxometry exhibited strong T2-weighted contrast (T2 = 0.015 s at 50 μg/mL for Fe₃O₄@MSN-NH₂/FA/OXA), confirming theranostic potential. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) studies revealed variable Folate receptor alpha (FOLR1) expression among colorectal cancer cell lines (Caco2, SW620, SW48, and T84), with Caco2 demonstrating high levels. MTT assays indicated selective targeting of FOLR1-positive cells by FA-functionalized NPs (Fe₃O₄@MSN-NH₂/FA). This multi-functional drug delivery system integrates targeted delivery, MRP release, and real-time imaging, offering a promising technique for precision oncology. Full article

This manuscript reports a green approach for producing multifunctional acrylic fabrics co-decorated with Fe₃O₄ and Ag nanoparticles using Brachychiton populneus extract. Acrylic fabric was first amidoxime-functionalized to enable strong anchoring of Fe₃O₄ nanoparticles, followed by in situ deposition of AgNPs, during which the extract’s phytochemicals acted as reducing and stabilizing agents. FTIR, SEM/EDX, and VSM analyses confirmed successful surface modification and nanoparticle incorporation. The sequential treatments produced measurable add-on values (16.7% after amidoximation, followed by 10.9% and 8.5% after Fe₃O₄ and AgNP deposition, respectively). The Ag/Fe₃O₄-coated fabrics exhibited enhanced hydrophobicity and strong antimicrobial activity, with inhibition zones up to 14 mm against bacteria (including MRSA) and 26.9 mm against fungi at the highest Ag loading. Antioxidant activity was also markedly improved, showing up to a 78-fold increase in reducing power. Overall, this sustainable plant-mediated route provides an effective strategy for developing antimicrobial and antioxidant acrylic textiles for technical and protective applications. Full article

Zn_1−xFe_xO nanocomposites (NCs) with varying Fe concentrations (x = 0, 0.1, 0.2, 0.3, and 0.4) were effectively prepared using the hydrothermal approach, and their morphology, structural, optical, and magnetic properties were systematically analyzed. XRD analysis confirmed Fe doping reduced crystallinity and crystallite size. TEM images of Zn_1−xFe_xO NCs exhibited smaller and more agglomerated nanostructures compared to the pure ZnO NPs. Raman and XPS analyses indicated increased lattice disorder, oxygen vacancies, and the coexistence of Fe²⁺/Fe³⁺ species. UV–Vis spectra showed enhanced visible light absorption and a tunable band gap, while PL results reflected defect-induced emission shifts and quenching, associated with zinc vacancies, interstitials, and oxygen-related defects. Magnetic measurements revealed a transition from diamagnetism to ferromagnetic-like behavior at room temperature for Fe content x ≥ 0.2, with magnetization strongly dependent on doping level. These results highlight Zn_1−xFe_xO for advanced optoelectronic and spintronic applications. Full article

The stability of nanoparticles (NPs) in ODS steel is an important factor affecting their long-term service behavior. In the current work, the 9Cr-ODS steel samples were irradiated using 3.5 MeV Fe¹³⁺ ion irradiation up to 20 dpa at 350–650 °C, and the microstructure stability was studied using the transmission electron microscope. The correlation between the particle coarsening rate and the irradiation depth has been investigated. The results show that fine Y-Ti-O NPs undergo coarsening under irradiation at 350 and 500 °C, and the coarsening rate shows a trend of first increasing and then decreasing with the increase in depth. NP coarsening reached its peak at a certain depth, and the peak depth increased with the increase in irradiation temperature. While the coarsening was inhibited at 650 °C, almost no changes in particle size were observed, only slightly coarsening at the end of the irradiation layer. In addition, b = 1/2<111> type dislocation loops were dominant at 350 °C, and the formation of b = <100> type dislocation loops was confirmed at 500 °C. Dislocation lines were formed at 650 °C. Additionally, the segregation of Cr, O, C, Y, and Ti toward the surface in the irradiated layer was observed due to the surface effect. The stability of NPs with irradiation temperature is discussed. Full article

This paper introduces a streamlined three-step synthesis method for crafting porous Fe₂O₃/ZnO nanofibers (NFs). Initially, Fe₂O₃ nanoparticles (NPs) were synthesized using the hydrothermal method. Subsequently, PVP NFs laden with Fe₂O₃ NPs and zinc salt were synthesized via an electrospinning method. Finally, porous Fe₂O₃/ZnO NFs were fabricated through calcination, resulting in an average diameter of approximately 100 nm. Gas-sensing experiments illuminate that the porous Fe₂O₃/ZnO NFs exhibit outstanding sensitivity, selectivity, and robust long-term stability. Although the response magnitude decreased under high relative humidity (RH) due to competitive adsorption, the sensor maintained distinct detectable responses towards NO₂ vapor at an optimum temperature of 225 °C. Particularly noteworthy is the substantial enhancement in NO₂ sensing properties observed in the Fe₂O₃/ZnO composite compared to pure ZnO NFs. This enhancement can be ascribed to the distinctive microstructure and heterojunction formed between Fe₂O₃ and ZnO. Full article

Developing precise tumor-targeting delivery systems while minimizing off-target toxicity continues to pose significant challenges in medicine application. The integration of two different functional materials has emerged as a promising strategy in current biomedical research. Herein, a hybrid nanocomposite consisting of Fe₃O₄ and ZnO was synthesized via a simple approach and employed as a nanoscale drug delivery system to explore the loading capacity and stimuli-responsive release characteristics of the anticancer agent doxorubicin (DOX). Results show that the synthesized nanoparticles (NPs) exhibit a multi-scale nanostructure consisting of the spindle-like ZnO nanorods with a mean length of 280 nm, on which the Fe₃O₄ NPs with a diameter of around 16 nm are uniformly dispersed. The ZnO@Fe₃O₄ NPs possess superparamagnetic behavior and a fast response to the external magnet and demonstrate exceptional near-infrared (NIR) photothermal conversion efficiency. In drug release studies, the ZnO@Fe₃O₄ NPs achieve the controlled DOX release in the simulated acidic tumor microenvironment as well as NIR laser irradiation. Further, the ZnO@Fe₃O₄-DOX composites significantly suppress the viability of human cervical cancer cells (HeLa) upon laser activation. These findings suggest that ZnO@Fe₃O₄ NPs are promising candidates for combined photothermal therapy, magnetic-targeted drug delivery, and stimuli-responsive controlled release applications. Full article

Zinc oxide nanoparticles (ZnO NPs) have garnered increasing attention in agriculture due to their potential to enhance plant growth and nutrient use. This research investigates the concentration-dependent effects of ZnO NPs on young crabapple (Malus robusta) plants, addressing gaps in understanding how different concentrations influence plant development. A hydroponic experiment was conducted, applying foliar treatments of 200 mg L⁻¹ ZnSO₄ (S200) and 200, 500, and 1000 mg L⁻¹ ZnO NPs (N200, N500, N100). The control group (CK) was treated with deionized water (dH₂O). Growth parameters, antioxidant enzyme activity, and nutrient contents were measured to evaluate the impact of ZnO NPs on plant development and nutrient uptake. The results showed that N200 enhanced growth, increasing plant height by 22.64%, total dry weight by 49.36%, and root length by 116.07%. In contrast, N500 and N1000 induced oxidative stress, elevating H₂O₂ and MDA by 32.02~54.43% and inhibiting growth. N200 also improved nutrient uptake, increasing K, Ca, Fe, and Zn uptake fluxes by 84.92%, 112.12%, 185.15%, and 149.92%, respectively, whereas N1000 suppressed overall nutrient uptake but increased root Ca accumulation by 64.59%. These findings suggest that ZnO NPs can enhance plant growth and nutrient utilization at low concentrations, with potential implications for agricultural practices involving nanoparticle (NP)-based fertilizers. Full article

In recent years, photocatalysis using semiconductor materials has gained significant attention as an effective strategy for dye degradation under mild conditions. Among various metal oxide photocatalysts, zinc ferrite (ZnFe₂O₄) has gained attention due to its narrow band gap, good stability, low cost, and activation under visible light. ZnFe₂O₄ nanoparticles (NPs) were synthesized using a co-precipitation process and tested for their photocatalytic effectiveness in degrading synthetic dyes Fast Green FCF and Orange II Sodium Salt under visible light. This study emphasizes the benefits of utilizing ZnFe₂O₄ as a visible light-activated, cost-effective, and environmentally friendly photocatalyst. These findings add to the growing research on wastewater treatment options. Full article