Properties Of Nanoparticles Research Articles

Enhanced Persistent Luminescence from Cr3+-Doped ZnGa2O4 Nanoparticles upon Immersion in Simulated Physiological Media

Near-infrared persistent luminescence (PersL) nanoparticles (NPs) have great potential in biomedical applications due to their ability to continuously emit tissue-penetrating light. Despite numerous reports on the distribution, biological safety and other consequences of PersL NPs in vitro and in vivo, there has been a lack of studies on the optical properties of these NPs in the physiological environment. In light of this, we investigated the effects of short-term immersion of the prominent Cr3+-doped ZnGa2O4 (CZGO) NPs in a simulated physiological environment for up to 48 h. This paper reports the changes in the structural and optical properties of CZGO NPs after their immersion in a phosphate-buffered saline (PBS) solution for pre-determined time intervals. Interestingly, the luminescence intensity and lifetime noticeably improved upon exposure to the PBS media, which is unusual among existing nanomaterials explored as bioimaging probes. After 48 h of immersion in the PBS solution, the CZGO NPs were approximately twice as bright as the non-immersed sample. X-ray spectroscopic techniques revealed the formation of ZnO, which results in an improvement in observed luminescence.

Evaluation of Antibacterial Properties of Zinc Oxide Nanoparticles Against Bacteria Isolated from Animal Wounds

Background/Objectives: This research aimed to determine the efficacy of metallic oxide nanoparticles, especially zinc oxide nanoparticles (ZnO-NPs), in inhibiting a wide range of bacteria isolated from animal wounds, indicating their potential as alternative antimicrobial therapies in veterinary medicine. Method: The disc diffusion technique, broth microdilution technique, and time-kill kinetic assay were performed to determine the antibacterial activity of the ZnO-NPs. Results: Transmission electron microscopy (TEM) and scanning electron microscopy (SEM showed that the ZnO-NPs were spherical and polygonal with sizes ranging from 50 to 100 nm, while DLS (NanoSizer) measured an average size of 512.3 to 535.7 nm with a polydispersity index (PDI) of 0.50 to 0.63 due to particle size agglomeration. The ZnO-NPs exhibited antibacterial activity against several bacterial strains isolated from animal wounds, including Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae, with inhibition zones ranging from 10.0 to 24.5 mm, average MIC values ranging from 1.87 ± 0.36 to 3.12 ± 0.62 mg/mL, and an optimum inhibitory effect against Staphylococcus spp. The time-kill kinetic assay revealed that the Zn-ONPs eradicated Staphylococcus spp. and Klebsiella pneumoniae, as well as Escherichia coli and Pseudomonas aeruginosa (99.9% or 3-log10 reduction), within 30 min of treatment. They also demonstrated a varying degree of antibiofilm formation activity, as indicated by the percentage reduction in biofilm formation compared to the untreated biofilm-forming bacterial strains. Conclusion: ZnO-NPs effectively inhibit bacterial growth and biofilm formation in animal wound isolates.

Effect of fine-tuned growth temperature on structural, morphological, optical, and electrical properties of Cu2O nanoparticles as candidates for supercapacitor applications

Abstract Cuprous oxide (Cu2O) nanoparticles are promising candidates for optoelectronic and energy applications due to their unique p-type semiconducting nature, optical and electrical properties. This work studies the impact of carefully controlled growth temperature on the structural and morphological, and electrical characteristics of Cu2O nanoparticles synthesized via a coprecipitation method under various temperatures (45°, 55°, 65°, and 75°C). The X-ray diffraction (XRD) analysis indicated a high crystallinity for the fabricated Cu2O nanoparticles with an average crystallite size of approximately (~29 nm), The TEM observations indicate an average particle size of approximately (~50 nm) nanometres. SEM results demonstrated a morphological transition from spherical-cubic to cubic as the aging temperature increased. The electrical properties of the prepared nanoparticles were investigated through AC conductivity and dielectric measurements were taken between 300 K and 550 K temperature range and frequencies ranged from 100 Hz to 5 MHz. Cu2O nanoparticles enhance supercapacitor performance by providing high dielectric constant at low frequencies, improving energy storage, and increasing AC conductivity for efficient charge transport. Their temperature-dependent behaviour and ability to minimize energy losses make them ideal for high-frequency and high-temperature applications. Our findings highlight the exceptional dielectric properties of Cu2O nanoparticles and their remarkable sensitivity to subtle changes in growth temperature. This fine-tuning of the growth conditions allows for the optimization of nanoparticle properties, these characteristics make them suitable candidates for supercapacitor energy applications and other emerging optoelectronic devices.

Positively Charged Nanoplastics Destruct the Structure of the PCK1 Enzyme, Promote the Aerobic Gycolysis Pathway, and Induce Hepatic Tumor Risks.

The production and weathering processes of nanoparticles (NPs) introduce charged functional groups on their surface. Previous studies have found that the surface charge properties of NPs play a critical role in their toxic effects and the mechanisms are generally attributed to their different accumulations and transmembrane potentials. Currently, we still lack sufficient knowledge about effects, owing to the unique structures of these polymers. In this study, positively charged NPs (PS-NH2, 50 nm) at 0.05-0.5 μg mL-1 promoted the proliferation of hepatic tumors in oncogenic KrasG12V zebrafish larvae and they also increased the viability of human hepatocellular carcinoma cells, whereas negatively charged NPs (PS-COOH, 50 nm) did not. We present evidence indicating that the potential carcinogenicity of PS-NH2 is related to the special polymer-molecular interactions caused by its positive surface charge. The affinity of PS-COOH chains for peptides typically enhances enzyme stability and upregulates its expression. However, PS-NH2 strongly competes with hydrogen bonds of the first rate-limiting enzyme PCK1 in gluconeogenesis, thus downregulating the expression of PCK1 and promoting the aerobic glycolysis pathway, which most tumor cells prefer. This study indicates that positive-charge modified NPs in the environment may bring additional carcinogenic risks.

Selective Adsorption to Pathogenic Bacteria Augments Antibacterial Activity via Adjusting the Physicochemical Property of Nanoparticles

AbstractOral antibiotics are the primary method used to treat bacterial infections in clinical practice. However, the non‐selectivity of antibiotics reduces the efficacy of treatment while also tending to damage normal flora and cause dysbiosis. Obviously, it is crucial to enhance the selectivity of antibiotics against bacteria. It is possible to modulate the physicochemical properties of orally administered nanosystems to achieve selective adsorption to bacteria, thereby achieving improving bactericidal effects. A series of nanoparticles are examined bacterial adhesion characteristics focusing on five aspects: particle size, shape, charge, surface hydrophilicity, and surface modification. Selective adsorption of nanoparticles is investigated pathogenic bacteria (S. aureus as an example), normal bacteria (E. coli as an example), and probiotic bacteria (E. faecium as an example). The results show that ≈50 nm chitosan‐modified spherical Poly(lactide‐co‐glycolide) (PLGA) nanoparticles exhibit a stronger adsorption capacity for pathogenic bacteria (Staphylococcus aureus). After loading with amoxicillin, the antibacterial nanoparticles are able to destroy pathogenic bacteria without disrupting the normal intestinal bacterial flora and reducing the typical side effects of ecological disruption caused by broad‐spectrum antibiotics. Thus, this work presents a convenient and versatile strategy for targeting bacteria to enhance the antibacterial efficacy of current antibiotics.

Formation Mechanisms of Protein Coronas on Food-Related Nanoparticles: Their Impact on Digestive System and Bioactive Compound Delivery

The rapid development of nanotechnology provides new approaches to manufacturing food-related nanoparticles in various food industries, including food formulation, functional foods, food packaging, and food quality control. Once ingested, nanoparticles will immediately adsorb proteins in the biological fluids, forming a corona around them. Protein coronas alter the properties of nanoparticles, including their toxicity, cellular uptake, and targeting characteristics, by altering the aggregation state. In addition, the conformation and function of proteins and enzymes are also influenced by the formation of protein coronas, affecting the digestion of food products. Since the inevitable application of nanoparticles in food industries and their subsequent digestion, a comprehensive understanding of protein coronas is essential. This systematic review introduces nanoparticles in food and explains the formation of protein coronas, with interactions between proteins and nanoparticles. Furthermore, the potential origin of nanoparticles in food that migrate from packaging materials and their fates in the gastrointestinal tract has been reviewed. Finally, this review explores the possible effects of protein coronas on bioactive compounds, including probiotics and prebiotics. Understanding the formation mechanisms of protein coronas is crucial, as it enables the design of tailored delivery systems to optimize the bioavailability of bioactive compounds.

Machine Learning-Integrated Numerical Simulation for Predicting Photothermal Conversion Performance of Metallic Nanofluids.

Photothermal conversion in metallic nanofluids, driven by localized surface plasmon resonances, is essential for applications in biomedicine, such as cancer treatment and biosensing. However, accurately predicting photothermal conversion performance, particularly the spatial temperature distribution, remains challenging due to the complex interplay of nanoparticle properties. Existing experimental methods are labor-intensive and often insufficient in providing detailed thermal profiles. Here, a novel approach that integrates machine learning is presented with numerical simulations to predict the photothermal conversion efficiency and spatial temperature distribution in gold nanorod nanofluid. The method employs Discrete Dipole Approximation for optical property calculations, Monte Carlo simulations for light transport, and finite element methods for temperature distribution modeling. The machine learning model, trained on 1,024 cases of photothermal conversion efficiency and 2,016 cases of temperature fields, achieves rapid and accurate predictions with a high correlation coefficient (R2 = 0.972) to simulation results. This approach not only streamlines the prediction process but also provides an accessible tool for optimizing nanoparticle design, with significant implications for advancing biomedicine, energy, and sensor technologies.

Structural and optoelectronic properties of CuS nano particles prepared by Co-precipitation method

Metal chalcogenide copper sulfide nanoparticles exhibit a broad spectrum of applications, encompassing solar cells, photovoltaics, optical devices, ionic materials and more. In this investigation, CuS nanoparticles were synthesized through a facile co-precipitation method. The synthesis involved employing copper sulfate and thiourea as precursors for Cu and S, respectively. Quantitative analysis, confirming the presence of Cu–S and S–S bonds, was conducted through Raman spectroscopy. X-ray diffraction (XRD) was employed to ascertain the structural phases. The semiconducting behavior of the synthesized CuS nanoparticles was studied through UV–Vis spectroscopy, correlating optical absorption and energy bandgap. The comprehensive findings suggest that the prepared CuS nanoparticles hold promise for advancements in photovoltaic technology and optical devices.

Exploring the dual role of BiVO4 nanoparticles: unveiling enhanced antimicrobial efficacy and photocatalytic performance

Abstract This study was focused on enhancing the structural, optical, antimicrobial, and photocatalytic activities of bismuth vanadate (BiVO4) nanoparticles. The current study utilized a simple hydrothermal technique to fabricate BiVO4 nanoparticles. Several techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman, Field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), and ultraviolet-visible (UV-Vis), were used to examine BiVO4. The monoclinic structure of BiVO4 was confirmed through XRD, XPS, and Raman analysis, validating its high purity and the absence of secondary phases with a size of 31 nm. The decahedral structure and purity of BiVO4 were revealed through FESEM-EDS microstructure and surface morphology examination. A band gap of 2.36 eV was exhibited by the synthesized BiVO4 nanoparticles. The conduction band minimum and valence band maximum edge potentials were found to be 2.715 eV and 0.355 eV, respectively. The antimicrobial properties of BiVO4 NPs were evaluated using the disc diffusion method on a broad spectrum of pathogens. Various bacterial and fungal pathogens showed broad-spectrum antimicrobial activity against BiVO4, indicating that BiVO4 nanoparticles (NPs) could be effective antimicrobial agents. In addition, the photocatalytic performance of BiVO4 and its degradation efficiency were investigated with Oxytetracycline (OTC), tetracycline (TC), and doxycycline (DC) antibiotics under visible light. The photocatalytic degradation results demonstrated that BiVO4 successfully degraded the antibiotic residuals. The results showed that the hydrothermally synthesized BiVO4 nanoparticles have great potential for use in biological and environmental applications. Graphical Abstract

Sol–gel synthesis of silicon oxide (SiO2) nanoparticles: exploring gas sensing and photocatalytic applications

In this research, silicon oxide (SiO2) nanoparticles (NPs) were synthesized using the sol–gel method. The synthesized materials were characterized through various techniques. Fourier transform infrared spectroscopy (FTIR) revealed the absorption band corresponding to Si–O–Si bonds. Ultraviolet–visible (UV–Vis) spectroscopy analysis indicated a band gap energy of 5 eV. X-ray diffraction (XRD) analysis displayed a broad peak, confirming the amorphous nature of the material. Field emission scanning electron microscopy (FESEM) further demonstrated a spherical morphology of the SiO2 NPs. The photocatalytic degradation of MB dye using SiO2 NPs has been examined, revealing promising and improved degradation properties. Even a small amount of SiO2 NPs achieved around 69.20% degradation of MB within 240 min, with the rate constant for the material being 0.001 min−1. The gas sensing properties of the SiO2 NPs were tested on domestic gas sensor units for different gases, including ethanol, methanol, CO2, LPG, H2S, NH3, O2, and Cl2, at temperatures ranging from room temperature to 300 °C. Among these materials, SiO₂ NPs displayed the strongest response to H₂S gas, showing outstanding gas-sensing performance at a concentration of 100 ppm. The response time was 18 S, with a quick recovery time of approximately 22 S.Graphical

Photocatalytic properties of Mn2O3 nanoparticles synthesized via green chemistry method

The objective of this work is to synthesize Mn2O3 nanoparticles (NPs) using green method based on olive leaf extract (OLE). These nanoparticles are intended for photocatalytic applications, specifically the degradation of pollutants and dyes using methylene blue (MB) as a test substance. The synthesized material, initially described as manganese oxide (Mn2O3), was characterized using various techniques: thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD), FT-IR, Raman and UV-visible spectroscopies. Additionally, the photocatalytic tests were performed. XRD analysis revealed the formation of Bixbyite (Mn2O3) phases. Raman and FT-IR spectroscopy confirmed the presence of Mn-O bonds within the synthesized material. The TGA results supported the decomposition of organic compounds and the formation of the Mn2O3. The photocatalytic degradation tests with methylene blue yielded promising results. The addition of the synthesized material (Mn2O3) significantly enhanced the degradation of methylene blue, achieving an efficiency of 87.8%.

Adoptive cell transfer of piezo-activated macrophage rescues immunosuppressed rodents from life-threating bacterial infections

Bacterial infections pose a significant threat to human health. Catalytic antibacterial nanoparticles that generate reactive oxygen species (ROS) are emerging, as a promising therapeutic approach in treating bacterial infection by boosting the innate immune defenses. However, the interaction between innate immune cells and these catalytic nanoparticles remains poorly understood. Here, by using rodent models of bacterial infection, we test the antimicrobial properties of ultrasound-responsive piezo-catalytic nanoparticles (piezoNP). We show that piezoNPs strongly interact with macrophages within subcutaneous abscesses caused by Staphylococcus aureus (S. aureus) infections, and demonstrate that this interaction enhances the macrophage-mediated antibacterial phagocytosis and killing activity through intracellular piezocatalysis. Moreover, we test the use of these piezo-activated macrophages (piezoMϕ) as adoptive cell therapy (ACT) for treating various immunosuppressive bacterial infections, including sepsis, pneumonia and peritonitis. Our study thus highlights the potential application of catalytic nanoparticles as a promising alternative to conventional infection treatment to effectively modulate the innate immune responses and to engineer macrophages for immunotherapy purposes.

Low-Temperature Synthesis of NiO Structures: Tailoring Morphology for Enhanced Dielectric Performance

Abstract Abstract:
Nickel oxide (NiO) is a widely studied material for energy storage applications due to its excellent structural and functional properties. This study explores the effect of synthesis pH on the structural, optical, and dielectric properties of NiO nanoparticles to optimize their performance. NiO was synthesized via a hydrothermal method at pH 8 and 12, followed by calcination at 200°C. At pH 12, X-ray diffraction confirmed the phase transition from β-Ni(OH)₂ to NiO, while TEM analysis revealed the formation of a one-dimensional (1D) structure. Optical studies using UV-visible spectroscopy and photoluminescence revealed defect states that contribute to improved energy storage performance. Dielectric studies revealed superior performance at pH 12. Electrochemical cyclic voltammetry confirmed the enhanced stability and energy storage capabilities of NiO with 1D structure. These findings establish NiO synthesized at pH 12 as a promising candidate for advanced energy storage technologies.
Keywords: NiO nanoparticles, hydrothermal synthesis, Optical properties, Dielectric properties, Energy storage.


Optical and Structural Properties of Rutile Nanoparticles Prepared Via Ball Milling

This study centered on determining the optical characteristics of Rutile nanoparticles and synthesizing them using a ball milling process. A top-down approach was utilized to obtain nanoparticles from the bulk materials utilizing high intensity ball milling technique. The crystalline size of the nanoparticle was ascertained using the Debye-Scherer formula. The Energy Band gap, optical conductivity, extinction coefficient, transmittance, and refractive index were among the optical characteristics that were identified. The average crystalline size obtained, was 87.440 nm. The computed dislocation density varied between (0.109x10-3 to 0.0359x10-3 ) nm-2. As the wavelength range shifted from the ultraviolet to the visible and near-infrared regions, the absorbance value was observed to decrease simultaneously. The refractive index of the particle showed a uniform result from 1eV to 4eV but sharply increased at 4.1eV and also dropped sharply at 4.3eV and then maintained a uniform outcome as the photon energy increased. The transmittance value was also observed to gradually increase from the ultraviolet region, to the visible region, hence reaching 99.9% in the near-infrared region. Furthermore, the band energy gap was obtained to be 3.88 eV. The unique properties of the Rutile nanoparticles revealed potential uses in photovoltaic and optoelectronic systems.

Gold nanoparticles for theranostic treatment of cancer

The chemical stability, low toxicity, and relative simplicity of methods for the synthesis and modification of gold nanoparticles open up wide possibilities for their use as theranostic agents for the diagnosis and treatment of cancer. The unique properties of gold nanoparticles, known as localized surface plasmon resonance, make it possible to create theranostic agents based on these nanoparticles, combining the capabilities of both in vitro diagnostics and targeted drug delivery. The high surface-area-to-volume ratio of gold nanoparticles significantly facilitates the creation of complex nanoplatforms, which can be used in several therapeutic and diagnostic areas at once.

Pengaruh Penambahan Doping Cerium terhadap Nilai Bandgap CuO dengan Metode Sol-Gel

Copper(II) oxide (CuO) has been recognized as a promising semiconductor material for various applications, such as photocatalysis, sensors, and renewable energy devices. However, its efficiency is often limited by a suboptimal bandgap value. This study aims to analyze the effect of cerium doping on the properties of CuO nanoparticles synthesized through the sol-gel process. The sol-gel method ensures a homogeneous doping distribution and produces nanoparticles with a stable structure. The bandgap energy of CuO nanoparticles was determined through characterization using UV-DRS. Cerium was introduced as a dopant in CuO at a concentration of 0.4 mmol, resulting in a bandgap value of 1.26 eV, whereas undoped CuO exhibited a bandgap of 1.35 eV. The analysis indicates that the Ce doping concentration significantly affects the bandgap of CuO nanoparticles, with a reduction observed at 0.4 mmol compared to undoped CuO. This decrease is attributed to symmetry disruption caused by doping, including oxygen vacancies, structural defects, and the presence of impurities that create additional energy levels within the bandgap. Furthermore, uniform microstrain and a smaller particle size contribute to structural disturbances that also influence the bandgap.

Synergistic Antibacterial and Antibiofilm Effects of Clindamycin and Zinc Oxide Nanoparticles Against Pathogenic Oral Bacillus Species

Oral bacterial pathogens, including Bacillus species, form biofilms that enhance antibiotic resistance, promote bacterial adherence, and maintain structural integrity. The ability of bacteria to form biofilms is directly linked to several oral diseases, including gingivitis, dental caries, periodontitis, periapical periodontitis, and peri-implantitis. These biofilms act as a predisposing factor for such infections. Nanoparticles, known for their strong antibacterial properties, can target specific biofilm-forming microorganisms without disturbing the normal microflora of the oral cavity. This study focuses on the biofilm-forming ability and clindamycin (CM) resistance of Bacillus species found in the oral cavity. It aims to evaluate the antibacterial and antibiofilm properties of zinc oxide nanoparticles (ZnO-NPs) against oral Bacillus species and assess the effectiveness of combining CM with ZnO-NPs in reducing antibiotic resistance. The antibacterial susceptibility of Bacillus isolates was tested using ZnO-NPs and CM, demonstrating synergistic effects that reduced the minimum inhibitory concentrations by up to 8-fold. The fractional inhibitory concentration (FIC) index indicated a significant synergistic effect in most strains, with FIC values ranging from 0.375 to 0.5. It was found that the majority of Bacillus strains exhibited significant biofilm-forming capabilities, which were reduced when treated with the ZnO-NPs and CM combination. The study also evaluated the cytotoxicity of ZnO-NPs on cancer cells (CAL27) and normal fibroblasts (HFB4). CAL27 cells showed stronger cytotoxicity, with an IC50 of 52.15 µg/mL, compared to HFB4 cells, which had an IC50 of 36.3 µg/mL. Genetic analysis revealed the presence of biofilm-associated genes such as sipW and tasA, along with antibiotic resistance genes (ermC), which correlated with the observed biofilm phenotypes. Overall, this study demonstrates the potential of combining ZnO-NPs with CM to overcome antibiotic resistance and biofilm formation in the oral bacterial pathogens, Bacillus species. These findings suggest new approaches for developing more effective dental treatments targeting oral biofilm-associated infections and antibiotic resistance.

Electrochemical properties of silver nanoparticles decorated aminosilicate functionalized TiO2 nanocomposite in hydrazine sensing

Electrochemical properties of silver nanoparticles decorated aminosilicate functionalized TiO2 nanocomposite in hydrazine sensing

Mechanical properties of High Entropy Alloy nanoparticles obtained by nanoindentation: A BCC HfNbZrTaTi and FCC FeNiCrCoCu case

Mechanical properties of High Entropy Alloy nanoparticles obtained by nanoindentation: A BCC HfNbZrTaTi and FCC FeNiCrCoCu case

To Explore the Antimicrobial Properties of Co- doped CdO Nanoparticles prepared by sol-gel Citrate Techniques

This study focuses on the synthesis of Cadmium oxide (CdO) nanoparticles with doped transition metals like Cobalt (Co) of varying concentrations using sol gel citrate synthesis. Chemical and elemental characterization was carried out with X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-Visible (UV-Vis) spectroscopy, Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS). The efficacy of antimicrobial properties of the synthesized nanoparticles against a wide range of Gram-positive and Gram-negative bacterial strains and fungal strains was explored. The results demonstrates that the doping of transition metals enhances the antibacterial and antifungal properties of the CdO nanoparticles and thus it can be used as antimicrobial agent in various industrial and medical fields due to its potential strength.