Applied Nanoscience最新文献

The growing global demand for sustainable energy solutions has led to a surge of interest in bioethanol production from lignocellulosic biomass. However, low productivity, inefficient substrate conversion, and inadequate fermentation kinetics restricts its economic. This research addresses these issues by exploring the use of nanotechnology, mainly iron oxide (Fe₃O₄) nanoparticles, to enhance fermentation efficiency for bioethanol synthesis from sugarcane bagasse. Methodologically, 100 g of sugarcane bagasse was pre-treated with 10% (w/v) sulfuric acid, followed by pH adjustment using calcium hydroxide. The hydrolyzed mixture underwent fermentation with Saccharomyces cerevisiae in the presence of varying concentrations of Fe₃O₄ nanoparticles (0.05 g, 0.10 g, 0.15 g, and 0.20 g). Bioethanol yield was monitored over 7 days, and the samples were distilled to quantify bioethanol production. Results indicate that the addition of Fe₃O₄ nanoparticles significantly improved bioethanol yield. The sample containing 0.20 g of nanoparticles achieved the highest bioethanol concentration of 19.4% (v/v) and exhibited the most substantial reduction in sugar levels from 8.5% (w/v) to 4.20% (w/v) as well as a decrease in pH from 5.50 to 3.50 over the fermentation period. ANOVA confirmed that iron oxide nanoparticles and fermentation time had a significant impact on ethanol yield (p < 0.05). Tukey HSD showed significant improvement up to 120 h with stabilization thereafter. Increased concentrations of nanoparticles had a greater impact on ethanol yield, and this reveals synergistic role with fermentation time to maximize output. Hence, the incorporation of Fe₃O₄ nanoparticles enhances the bioethanol production process from sugarcane bagasse, making it a viable method for improving bioethanol yield in lignocellulosic biomass fermentation.

Wheatgrass-extracted nanoemulsion (NE) and nanoemulgel (NEG) were developed and tested to improve topical delivery and dermal therapeutic efficacy. The wheatgrass extract’s solubility and emulsification efficiency determined the excipients: orange oil, Tween 80, and Carbitol. The pseudoternary phase diagram showed that the 2:1 Smix (Tween 80: Carbitol) ratio produced the largest monophasic nanoemulsion area. F3, the optimised formulation, had nanodroplets of 121.48 nm, a low polydispersity index (PDI) of 0.251, and a negative stability zeta potential of -26.29 mV. The formulation was thermodynamically stable under heating/cooling cycles, centrifugation, and freeze/thaw tests. The nanoemulgel containing Carbopol 940 exhibited favourable rheological and physicochemical properties, including a pH of 6.48 ± 0.12, a viscosity of 4870 ± 25 cP, good spreadability, and homogeneity. Drug content was particularly high at 96.38%. The drug form NA released 95.11% at 24 h, compared to 86.42% for NA. The test NEG penetrated excised skin with 95.08% permeation after 24 h and increased skin deposition (1041.49 µg/cm²) compared to standard gel formulations. Cytotoxicity studies on A431 skin carcinoma cells showed the negative test formulation was safe, with cell viability exceeding 50% and NEG IC₅₀ greater than 5624 µg/mL. These findings suggest that the wheatgrass nanoemulgel may be a safe and effective dermally directed therapeutic delivery system.

Using Sol–gel method Lanthanum titanate (La₂Ti₂O₇) nanoparticles was synthesized and its performance as recombination blocking layer in dye-sensitized solar cells (DSSC) was studied. Formation of Monoclinic phase La₂Ti₂O₇ was confirmed from X-ray diffraction (XRD) and Raman analysis respectively. Samples morphology studied through Field Emission Scanning Electron Microscope (FE-SEM) and High-Resolution Transmission Electron Microscopy (HRTEM) revealed the layered structure of the material. The elemental composition of La₂Ti₂O₇ were confirmed by Energy Dispersive X-ray Analysis (EDAX)_, and the Selected Area Electron Diffraction (SAED) pattern revealed the polycrystalline nature of a material. UV–VIS and photoluminescence spectroscopies were used to study its light absorption and emission properties respectively. Furthermore, the photovoltaic performance of the La₂Ti₂O₇ based blocking layers in DSSCs was evaluated through J-V characterization and its charge kinetics were studied using Electrochemical impedance spectroscopy (EIS) respectively. These findings suggest that La₂Ti₂O₇ has promising capabilities as an effective recombination-blocking layer at the photoanode/electrolyte interface in dye-sensitised solar cells.

This study developed an antibacterial film using silver nanoparticles (AgNPs) embedded in a genipin-reinforced regenerated silk fibroin (GSF) matrix. Silk fibroin (SF) efficiently reduces silver ions to stable AgNPs, ensuring their dispersibility and size stability. Genipin, a biocompatible natural crosslinker derived from gardenia, enhances the film’s stability and biocompatibility, aligning with green synthesis principles. Electron microscopy revealed that the GSF-AgNP film has a porous structure with evenly distributed AgNPs, averaging 25 nm in size. This porous morphology increases the material’s surface area, facilitating silver ion release and boosting antibacterial activity. Dynamic light scattering indicated slight aggregation of GSF-AgNPs in solution, though it did not significantly affect antibacterial performance. X-ray diffraction showed that SF reduction and genipin modification confer good dispersibility and partially amorphous characteristics to AgNPs, enhancing material stability and antibacterial properties. Stability tests demonstrated the film’s low solubility in Dulbecco’s Modified Eagle Medium, highlighting its suitability for long-term applications. Antibacterial tests confirmed strong inhibitory effects against Staphylococcus aureus and Escherichia coli, achieving high efficacy with minimal AgNP concentrations. The GSF-AgNP film combines excellent stability and antibacterial potential, making it a promising candidate for biomedical applications, particularly in biological dressings.

The need for new environmentally friendly materials has become more critical than ever to prevent the acceleration of environmental degradation driven by global population growth. Biopolymer derivatives—renewable resources widely used in nature and in numerous human applications—have attracted growing interest due to their abundance, recyclability, and potential to replace conventional chemical plastics. In this study, we report the fabrication of periodic dielectric templates using soft lithography on pure corn-starch polyglucan films (with defined amylose and amylopectin content). Subsequent metallization of these sub-micrometer patterned films produces plasmonic structures supporting surface plasmon resonance (SPR) applications. This approach provides a simple and repeatable method for generating structural color on dielectric biopolymers, a property typically arising from crystalline and amorphous lamellae formed by amylose double helices and branched amylopectin segments. However, this study focuses only on SPR peaks via UV–Vis spectrum comparisons. The starch-based periodic dielectric templates exhibit environmentally friendly characteristics and, depending on the biopolymer derivative used, may be either water-soluble or water-insoluble. Starch films templated into various submicrometer sizes display tunable structural colors and can be engineered as biodegradable biopolymer-based timers. Furthermore, the plasmonic interface can enhance the photoluminescence of metal surfaces or organic dye–containing layers. We also demonstrate the fabrication of plasmonic arrays with precise optical properties via metallization of these periodic dielectric templates.

This comprehensive study focuses on Gd³⁺ substituted Mn-Cd nanoferrites, represented by the chemical formula Mn_0.3Cd_0.7Gd_xFe_2-xO₄ (MCGF). The dopant ion used was Gd³⁺, with x values ranging from 0.000 to 0.025. We prepared the samples for this research and conducted an extensive analysis using XRD, FTIR, TEM, SEM, and SAED techniques. The XRD patterns confirmed the presence of a spinel structure. Notably, the average crystallite size determined from the XRD analysis was between 32 and 36 nm, which aligns with the results from the TEM analysis. Additionally, the lattice parameters increased with the substitution of the metal ion (Gd³⁺), clearly demonstrating the effect of doping on the structure of the material. The examination of the dielectric properties provided crucial insights: both the dielectric constant (ε’) and dielectric loss (ε") increased with temperature. This is linked to the enhanced sample polarization and suggests that higher temperatures promote dipole relaxation, resulting in an increased dielectric loss. Samples exhibiting significant dielectric losses are particularly valuable for electromagnetic interference shielding applications. We also explored the AC conductivity of the samples and analyzed the relationship between the conductivity and frequency for various doping levels. This investigation offers insights into the behavior of materials at different doping levels and temperatures. The discussion on how the AC conductivity increases with temperature and frequency is particularly intriguing, given the material behavior. Furthermore, we examined the frequency dependency of the real part Z’ and imaginary part Z’’ of the impedance and provided detailed plots. The Nyquist plots and observed relaxation phenomena are crucial for understanding the electrical characteristics of materials. Gas detectors, storage devices, and other devices that can be developed from these synthesized materials are important for modern technologies.

This experimental study examines the characterization and efficacy of modified Zinc Oxide nanoparticles (ZnO NPs), enhanced using a low-level continuous-mode laser at a wavelength of 405 nm, for the control of worker and soldier castes of the termite species Macrotermes malaccensis (Holmgren). The ZnO NP samples were divided into three treatment groups: un-irradiated, 15-min irradiated, and 30-min irradiated. Laser irradiation was conducted using a 405 nm diode laser (THS-1220, China) at a power output of 500 mW, with a beam spot size of 4.0 mm and a fixed distance of 10 cm from the sample surface. Termites were exposed to serial dilutions of the ZnO NP treatments. Statistical analysis revealed a significant difference in mortality rates among the treatment groups (F_(6,36) = 4.75, (p<) 0.05). Notably, the 30-min irradiated ZnO NPs at a concentration of 1 mg/mL resulted in 100% mortality within 36 h. While both irradiated treatments demonstrated significantly higher efficacy than the control, there was no significant difference in mortality rates between the 15- and 30-min irradiated groups. These findings suggest that laser modified ZnO nanoparticles, when used at the appropriate wavelength and power, offer a promising and effective approach for termite control.

Commercial wet wipes were used as an inexpensive template to create zinc oxide (ZnO) and copper oxide (CuO) nanoparticles (NPs) by the combustion technique. Regulated nucleation and growth were made possible by the steady precursor adsorption provided by the fibrous network of wipes. While surface and elemental analysis revealed distinctive morphological features, particle size distribution, and high purity, X-ray analysis verified the formation of phase-pure crystalline ZnO and CuO. Reduced band gaps (2.60 eV for ZnO and 1.90 eV for CuO) were found by UV-Vis absorption analyses, which were explained by defects related to oxygen vacancies during the templating process. CuO outperformed ZnO at higher dosages in the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay, which showed concentration-dependent radical scavenging activity. There were notable dose-dependent inhibitory zones in the antibacterial efficacy against S. aureus and E. coli. In a concentration-dependent manner, ZnO and CuO NPs both prevented S. aureus and E. coli from forming biofilms. These results demonstrate the creative use of commercial wipes as long-term templates for the production of functional NPs with intriguing antibacterial properties.

Plant-derived bioactive compounds have garnered significant interest due to their potent therapeutic benefits, including antimicrobial, anti-inflammatory, and anticancer activities. However, their clinical application is hampered by inherent drawbacks such as poor solubility, chemical instability, and lack of multifunctionality in conventional formulations. Addressing these limitations, we report the green synthesis of a multifunctional nanocomposite composed of curcumin (phytochemical), chitosan (biopolymer), aloe vera (natural stabilizer), and graphite nanosheets (nanocarbon reinforcement) aimed at combined infection control and liver cancer therapy. The nanocomposite exhibited hydrodynamic sizes in the range of approximately 700 to 850 nm and demonstrated a positive surface charge (+ 51.1 mV), indicative of high colloidal stability. Fourier Transform Infrared (FTIR) Spectroscopy analysis confirmed successful integration of each component through characteristic functional groups. Biological evaluations revealed potent antimicrobial activity against clinically relevant pathogens such as Staphylococcus aureus and Candida albicans, alongside significant anti-inflammatory effects exemplified by membrane stabilization and hemolysis inhibition in erythrocyte assays. Crucially, the nanocomposite showed dose-dependent cytotoxicity toward HepG2 liver carcinoma cells (IC₅₀ ≈ 60 µg/mL), with associated apoptotic morphological changes. The synergistic assembly of phytochemicals, biosafe polymers, and nanocarbons into a single eco-friendly platform offers a promising approach to effectively address oxidative stress, microbial infections, and tumor progression, positioning this nanocomposite as a sustainable candidate for future biomedical applications.

The study investigates the therapeutic potential of Acacia catechu, a medicinal plant, in the context of inflammatory bowel disease, specifically Crohn’s disease. Utilizing a rat model, the research evaluates the protective effects of both standard extracts and nano formulations of Acacia catechu against colonic damage induced by dextran sulfate sodium. The methodology includes extracting active compounds from the bark of Acacia catechu, followed by pharmacological assessments of antioxidant enzyme activities and histopathological evaluations. Results indicate that the standard extract and nano formulation significantly improve colon health, as evidenced by enhanced colon weight-to-length ratios, better stool consistency, and reduced tissue damage compared to control groups. The antioxidant properties of Acacia catechu, attributed to its bioactive compounds, play a crucial role in mitigating oxidative stress and inflammation. The study highlights the potential of nano formulations of Acacia catechu to enhance the bioavailability of these compounds, suggesting a promising avenue for developing effective treatments for Inflammatory bowel disease. Overall, the findings support the integration of Acacia catechu into therapeutic strategies for managing chronic inflammatory conditions, warranting further research to validate these effects in human populations.