Properties Of Nanoparticles Research Articles

Computational analysis of heat transport dynamics in viscous dissipative blood flow within a cylindrical shape artery through influence of autocatalysis and magnetic field orentation

Nanofluids consisting of tetra nanoparticles are crucial in bio medical sciences due to their improved thermal transport characteristics. The advanced tailored properties of tera nanoparticles make them useful in several medical interventions, such as hyperthermia treatment, where the targeted tissue can be heated more efficiently, leading to better treatment outcomes. The current study investigates the heat transfer enhancement in a hemodynamic system using tetra nanoparticles. The physical configuration of the blood flow is assumed with in a permeable cylindrical shape stenosed artery. The model incorporates the Carreau model with inclusion of diverse factors such as, exponential space-based heat source, viscous dissipation, infinite shear rate and permeability of surface. Additionally, impact of chemical reaction (autocatalysis) and magnetohydrodynamic (MHD) consequences is also integrated into the system. The framed partial differential equations (PDEs) generated by physical problem are converted into new dimensionless form of an ordinary differential system (ODEs). Bvp4c MATLAB procedure is fetched for numerical investigation. It is observed that, velocity profile of the fluid is reduced due to intensification in inclined magnetic effect, whereas autocatalysis effect promotes the concentration of nanoparticles in blood flow mixture, which increases the temperature field of fluid. Furthermore, augmentation in the values of Wassenberg number increased the elasticity in blood which enables it to deform and stretch more readily in reaction to alterations in flow conditions and hence reduction is seen in overall blood flow rate. The results revealed the significance of these integrated factors for accurate modelling of blood flow passing through a stenosed artery, which is crucial in medical interventions.

Photoluminescence properties of SnO2 nanoparticles doped with group VI elements (Cr, Mo, W) synthesized by pulsed laser ablation in liquid

Tin oxide nanoparticles (SnO2 NPs), both pure and doped with Group VI (G6) metal ions (Cr+3, Mo+5, and W+6), were synthesized using pulsed laser ablation in liquid. This study aimed to investigate the effect of G6 doping on the electronic properties of SnO2 NPs, with an emphasis on enhancing their photoluminescence for optoelectronic applications. Transmission electron microscopy revealed well-crystallized samples with diameters of 3–6 nm, indicating quantum-confinement effects. The optical band gap, determined by UV–Vis spectroscopy, was reduced from 5.1 eV (undoped) to 4.9 eV (Cr-doped) due to defect states, while increasing to 5.3 eV and 5.7 eV for Mo- and W-doped SnO2, respectively, due to the Moss-Burstein effect. The photoluminescence spectra exhibited a redshift, with strong red emission around 700 nm, which was up to 90 % more intense than that of the undoped SnO2. This enhancement was attributed to the 2E→4A2 transition and increased defect states.

Antibiofilm and antibacterial activities of green synthesized ZnO nanoparticles against Erwinia amylovora and Pseudomonas syringae pv. Syringae: in vitro and in silico investigations

Today, many infections in plants are related to biofilm-developing bacteria. These infections can result in severe agricultural losses. Thus, this study aims to investigate the synergistic antibiofilm activity of Thymus vulgaris extract on the inherent antibacterial properties of ZnO nanoparticles against Erwinia amylovora and Pseudomonas syringae pv. syringae. Additionally, to gain insight into the molecular mechanisms of phytocompounds’ antibacterial activity, the molecular interactions of T. vulgaris phytochemicals with the TolC protein and TonB-dependent siderophore receptor were investigated through in-silico studies. Green-synthesized ZnO NPs (ZnO@GS) and chemically synthesized ZnO (ZnO@CHS) were evaluated using XRD and SEM techniques, showing a crystalline structure for both powders with average sizes of 50, and 40 nm, respectively. According to FT-IR and EDS spectroscopy, ZnO@GS was covered with thyme extract. Based on the in vitro results, all samples of ZnO NPs exhibited considerable antibacterial activity against both bacteria. At the same time, thyme aqueous extract alone proved considerably less effective at all tested concentrations. Compared to ZnO@CHS and thyme extract, the antibacterial efficacy of ZnO@GS against E. amylovora (MIC = 512 μg/mL) and P. syringae pv. syringae (MIC = 256 μg/mL) was significantly improved upon surface covering with thyme phytocompounds. Moreover, their antibiofilm properties were enhanced by almost 20 % compared to ZnO@CHS. In addition, molecular docking investigations showed that most of the phytocompounds could form stable interactions with the TonB-dependent siderophore receptor (P. syringae) plug domain and the TolC (E. amylovora) external channel. In vitro and in silico studies demonstrate that using the green approach for synthesizing ZnO NPs via thyme extract can notably boost its antibacterial and antibiofilm effects on the tested phytopathogenic bacteria.

Effect of the Dispersion Medium on NMR Relaxation Properties of Superparamagnetic Iron Oxide Nanoparticles between 0.24 mT and 14.1 T.

Due to weak exchange interactions, magnetite particles at a critical diameter of about 20 nm are considered monodomain. At this size, they exhibit a phenomenological magnetic property called superparamagnetism, making them useful as magnetic resonance imaging contrast agents, or MRI CAs. However, questions persist regarding the impact of using different physiological solvents and varying the environment in which these particles are dispersed on their performance, determined by their relaxivity. A colloidal suspension of superparamagnetic iron oxide nanoparticles (SPIONs) electrostatically stabilized by citrate ligand was synthesized using a fast, reliable, and reproducible developed microwave approach, ensuring high stability over time at pH 7. We studied the effects of three physiological media on these MRI CAs. Ultrapure water was used for the synthesis, while phosphate-buffered saline and physiological liquid were used to disperse the nanoparticles, as these media contain essential electrolytes for the functioning of the human body. The SPIONs underwent systematic characterizations to determine their physicochemical and magnetic properties. This study reports the longitudinal relaxivities of SPIONs at medically relevant magnetic field strengths. Field dependence of their relaxivity (efficacy) was evaluated using a nuclear magnetic resonance dispersion (NMRD) profile measured over a wide range of proton resonance frequencies between 5 kHz and 600 MHz. The Roch et al. model (Roch, A.; et al. J. Chem. Phys., 1999, 110, 5403-5411) was used to analyze the NMRD profile and evaluate the impact of SPIONs on water proton relaxation in the different redispersion media. It was observed in this study that the dynamics of water protons are not influenced by the redispersion media of these citrate-coated SPIONs. However, the presence of salt ions notably reduces their relaxivities by lowering the saturation magnetization of SPIONs.

Optimising nanoparticles: harnessing quality by design through 3-level factorial design and box-behnken methodology

Nanoparticles (NPs) have become essential elements in a number of scientific and industrial domains, such as materials research, drug delivery, and diagnostics, because of their special qualities and potential for focused uses. An ideal formulation procedure is essential to maximising the effectiveness and efficiency of nanoparticles. In order to optimise the formulation and production processes for nanoparticles, this research investigates the application of Quality by Design (QbD) principles in conjunction with sophisticated statistical approaches, namely the 3-level factorial design and the Box-Behnken methodology. The Quality by Design methodology is a methodical approach that prioritises predetermined goals, in-depth process comprehension, and careful control grounded in reliable science and quality risk management. When QbD is incorporated into nanoparticle optimisation, reliable and repeatable formulations that adhere to specifications with little variation are guaranteed. To look into how different factors interact and affect the properties of nanoparticles, the 3-level factorial design is used. With this design approach, a thorough understanding of the process variables can be obtained by exploring a broad variety of component values. Critical quality attributes (CQAs) include important parameters such drug encapsulation efficiency, zeta potential, polydispersity index (PDI), and particle size. These parameters are methodically examined to determine the ideal amounts of each. To further refine the 3-level factorial design, the Box-Behnken methodology is applied. Without the requirement for extensive combination testing, this response surface methodology (RSM) is especially useful for building second-order polynomial models and investigating quadratic response surfaces. By enabling a more accurate comprehension of the interactions between inputs and responses, the Box-Behnken design improves the optimisation process and makes it easier to identify the ideal circumstances for nanoparticle synthesis. By utilising both approaches in tandem, this work methodically determines ideal formulation parameters that minimise nanoparticle size and polydispersity while optimising stability and drug loading efficiency. The outcomes highlight how important a QbD framework is for directing the creation of reliable nanoparticle systems that function consistently and predictably.

Patient-Specific Nanoparticle Targeting in Human Leukemia Blood.

Antibody-directed targeting of chemotherapeutic nanoparticles to primary human cancers holds promise for improving efficacy and reducing off-target toxicity. However, clinical responses to targeted nanomedicines are highly variable. Herein, we prepared and examined a matrix of 9 particles (organic and inorganic particles of three surface chemistries with and without antibody functionalization) and developed an ex vivo model to study the person-specific targeting of nanoparticles in whole blood of 15 patients with chronic lymphocytic leukemia (CLL). Generally, anti-CD20-functionalized poly(ethylene glycol) (PEG) nanoparticles efficiently targeted CLL cells, leading to low off-target phagocytosis by granulocytes and monocytes in the blood. However, there was up to 164-fold patient-to-patient variability in the CLL targeting. This was further exemplified through using clinically relevant PEGylated doxorubicin-encapsulated liposomes, which showed high interpersonal differences in CLL targeting (up to 234-fold differences) and off-target phagocytosis (up to 65- and 112-fold differences in granulocytes and monocytes, respectively). Off-target phagocytosis led to almost all monocytes being killed within 24 h of treatment. Variance of the off-target association of PEGylated liposomes with granulocytes and monocytes significantly correlated to anti-PEG immunoglobulin G levels in the blood of CLL patients. A negative correlation between CLL targeting of PEG particles and anti-PEG immunoglobulin M levels was found in the blood. Taken together, our study identifies anti-PEG antibodies as key proteins in modulating patient-specific targeting of PEGylated nanoparticles in human leukemia blood. Other factors, such as the antigen expression of targeted cells and fouling properties of nanoparticles, also play an important role in patient-specific targeting. The human leukemia blood assay we developed provides an ex vivo model to evaluate interpersonal variances in response to targeted nanomedicines.

A Comparative Study About Physical Properties of Copper Oxide and Zinc Oxide Nanoparticles on Fagus orientalis L. as Bioindicator

A Comparative Study About Physical Properties of Copper Oxide and Zinc Oxide Nanoparticles on Fagus orientalis L. as Bioindicator

Heat and mass transfer in MHD flow of SWCNT and graphene nanoparticles suspension in Casson fluid

AbstractThe exceptional mechanical properties of carbon nanotubes (CNTs) and graphene nanoparticles, particularly their high aspect ratio and flexibility, position them as highly promising materials for the next generation of armor technology. Their incorporation into protective wear, such as bullet‐proof vests, offers the potential for significant improvements in both performance and cost efficiency. By replacing traditional materials with CNTs and graphene, the durability and maintenance of these protective devices could be substantially enhanced, leading to more effective and sustainable solutions for personal safety. This study focuses on the complex phenomena of heat and mass transport within a suspension of CNTs and graphene nanoparticles dispersed in a Casson fluid, particularly under the influence of an applied magnetic field. The analysis begins by reformulating the governing equations using similarity variables to transform them into a dimensionless form to simplify the problem. The resulting dimensionless equations are then solved using the three‐stage Lobatto IIIa finite difference method, a robust numerical technique well‐suited for solving boundary value problems in fluid dynamics. The results of this investigation highlight a significant 78.41% reduction in skin friction when compared with traditional CNT‐water nanofluid systems. This considerable decrease in skin friction not only reveals the superior performance of the CNT‐graphene nanofluid suspension but also opens up new possibilities for the design and development of advanced protective materials. These findings contribute to the growing body of knowledge on nanofluid applications and offer valuable insights for future research in the field of advanced armor technology.

Photoluminescence and photocatalytic activity of sol gel synthesized Mg doped TiO2 nanoparticles

The influence of magnesium doping on the optical properties, structural characteristics, and photocatalytic performance of TiO2 nanoparticles was investigated. Pure and Mg-doped TiO2 nanoparticles with varying weight percentages of magnesium were synthesized via the sol–gel method, followed by calcination at 100 °C for 12 h and annealing at 400 °C for 2 h to promote crystallization. X-ray diffraction (XRD) analyses confirmed the formation of crystalline mixed phases of anatase and rutile TiO2 nanoparticles, exhibiting their crystalline nature upon synthesis. Scanning electron microscopy (SEM) images were employed to study the morphological features of the samples, while energy dispersive spectroscopy (EDS) provided insights into their elemental composition. Photoluminescence (PL) emission spectra revealed ultraviolet (UV) to visible region emission for both pure and doped TiO2 samples. The photocatalytic activity was evaluated by monitoring the degradation of methyl orange under natural sunlight irradiation, elucidating the impact of visible light exposure. Furthermore, investigations were conducted to assess the influence of catalyst loading, initial dye concentration, and pH of the dye solution on the methyl orange removal efficiency. The 3 wt% Mg doped TiO2 exhibited 95 % of decolorization of Methyl Orange. X-ray photoelectron spectroscopy measurements was performed to verify the elemental composition and chemical valence states of each element. The scavenger test in photodegradation mechanism revealed that the main reactive species was superoxide species. The electron species resonance (ESR) measurement demonstrate that the synthesized sample shows the low spin state of Mg2+ in TiO2. The correlation between Mg doping on photocatalytic activity and crystal structure were studied. Theoretical calculations were performed to gain insights into the potential mechanism underlying the tuning of luminescent and photocatalytic properties of Mg-doped TiO2 nanoparticles, enabling a comprehensive discussion.

Green synthesis of ZnO, Fe3O4, and TiO2 nanoparticles: exploring enhanced bacterial inhibition, catalysis, and photocatalysis for sustainable environmental applications

ABSTRACT This study investigates the physicochemical and biological properties of metal oxide nanoparticles (TiO2, ZnO, and Fe3O4) synthesised via the phytosynthesis method using an extract from Boerhaavia diffusa leaves (BDL). The proteins and phenols present in the BDL extract played essential roles in reducing and stabilising TiO2, ZnO, and Fe3O4 nanoparticles. The study reveals size-dependent morphological, structural, and biological characteristics of the produced nanoparticles. FTIR spectra confirm the involvement of BDL extract in the synthesis process of TiO2, ZnO, and Fe3O4 nanoparticles. Transmission electron microscopy (TEM) analysis of TiO2 nanoparticles identified small, spherical particles (9 nm in diameter). BDL-derived TiO2, ZnO, and Fe3O4 demonstrated significant photocatalytic activity, achieving degradation rates of 98.96%, 96.26%, and 94.42%, respectively, in the decomposition of mono-azo dye after 40 minutes of UV irradiation. The reaction rates for BDL-derived TiO2, ZnO, and Fe3O4 were 0.367/min, 0.186/min, and 0.061/min, respectively, when catalysing the reduction of 4-Nitrophenol (4-NP) to 4-Aminophenol using NaBH4. BDL-derived TiO2 nanoparticles exhibited significant antibacterial effectiveness, showing a 23.6 mm zone of inhibition against Salmonella typhi. The BDL-derived TiO2, ZnO, and Fe3O4 nanoparticles exhibited remarkable cytotoxicity against lung cancer cell lines with IC50 values of 76.36 µg/mL, 90.21 µg/mL, and 94.61 µg/mL, respectively. This study reveals the potential of BDL-derived TiO2, ZnO, and Fe3O4 nanoparticles for applications in antibacterial, anticancer, catalytic, and photocatalytic fields, contributing to sustainable development of multifunctional nanomaterials for various technical and environmental advancements.

Nanofiberous composite with CuO-Ag0 supported on bamboo/lycra for protection against transmittable infectious diseases

The transmittable infectious diseases, detrimental environmental contaminants and harmful UV radiations remained constant threat to human civilization. Cold, pneumonia, tuberculosis bacteria, rubella virus, RSV and COVID19, then urban and industrial emissions, volcanic eruptions, pollen, aerosols on one hand and skin cancer, sunburn, premature ageing and skin tanning on the other hand are some of the examples of serious risks to health, safety and well-being. The WHO reported over 7million worldwide deaths due to hazardous air contaminants. Exploiting the tremendous features of nanofiberous structure and excellent microbiocidal properties of Ag0 and CuO nanoparticles, a sustainable and stable nanofiber based composite Bmb-nanoNP was developed. Utilization of biocompatible, biodegradable, nontoxic and environmental friendly polymers enabled the composite as sustainable source for protective clothing purposes. The microparticulate filtration of Bmb-nanoNP was 99.13 % and 96 % with and without air suction respectively. The microbiocidal affect against E. coli and S. aureus strains was excellent(5.9 % and 8.86 % cell viabilities respectively). Similarly, the Bmb-nanoNP showed calculated UV protection factor (UPF) of 7954 (50 + rating).These characteristics demonstrated potential candidacy of the Bmb-nanoNP composite for multi-functional safety clothing applications.

A Comparative Study on the in vitro Cytotoxicity and Anti-Cancer Properties of Gold Nanoparticles Derived from Elettaria cardamomum

A Comparative Study on the in vitro Cytotoxicity and Anti-Cancer Properties of Gold Nanoparticles Derived from Elettaria cardamomum

An improved amperometric cholesterol biosensor based on cholesterol oxidase nanostructures for pre-diagnosis of myocardial infarction

Cholesterol plays a pivotal role in human health, serving as a crucial biomarker for cardiovascular diseases, including myocardial infarction. This study presents the development of an innovative amperometric cholesterol biosensor that enhances the detection and quantification of cholesterol levels in serum. The biosensor integrates cholesterol oxidase (ChOx) nanoparticles with a modified electrode, leveraging the unique properties of platinum nanoparticles (PtNPs) and graphene nanosheets (GNs) to improve sensitivity and stability. The synthesis of PtNPs was achieved using Camellia sinensis extract, while graphene oxide was reduced to form GNs. At 2.39 mg/mL or above is deemed a biomarker for cardiovascular disorders, peripheral artery disease, heart attack, diabetes mellitus, strokes, and hypertension. The monitoring of serum cholesterol level is therefore very significant. In the present study, an innovative amperometric cholesterol biosensor was constructed by immobilizing nanoparticles of cholesterol oxidase onto a pencil graphite (PG) electrode modified with graphene nanosheets (GNs), platinum nanoparticles (PtNPs), and chitosan (CHIT). At various stages of construction, the modified electrode was characterized by employing electrical impedance spectroscopy (EIS) and cyclic voltammetry (CV), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) spectroscopy. The biosensor responded best when run at 0.14Vs-1 at optimal pH and temperature of 8.0 and 35°C respectively. The biosensor has a wide linear range (0.1mg/mL-7.5 mg/mL), with great sensitivity (0.89 mA cm−1mgmL−1) and a low limit of detection (0.97 mg/mL). This research not only contributes to the field of biosensing but also offers a promising tool for the early diagnosis of cholesterol-related health issues, paving the way for enhanced cardiovascular disease management.

Poly(Lactic-co-Glycolic Acid Nanoparticles Loaded with Docetaxel and Coated with Chitosan, Carboxymethyl Chitosan, or Glycol Chitosan.

Docetaxel (DTX) is a chemotherapeutic drug that has high toxicity and low bioavailability. To solve these problems, PLGA nanoparticles (NPs) were loaded with DTX and coated with mucoadhesive polymers; chitosan (CS), carboxymethyl chitosan (CMCS), or glycol chitosan(GCS). The NPs were characterized for size, charge, and polydispersity. The particles were explored using SEM, FTIR, DSC, and XRD. In vitro studies were performed to evaluate the mucoadhesive properties of the NPs and the drug release. The results validated the successful formation of spherical and monodispersed DTX NPs. The coated NPs exhibited highly positive charges, reaching +44.30±0.21 mV, whereas the uncoated NPs were almost neutral. The formulations demonstrated excellent encapsulation efficiency (>98%) and loading capacity (>45%). All polymers used in the coating process enhanced the mucoadhesive properties of PLGA NPs and sustained DTX release. Both the mucoadhesiveness and release were related to the used coating polymer and its concentration. The formulations were stable for up to three months in the refrigerator. In conclusion, loading DTX in PLGA NPs and coating them with CS, CMCS, or GCS provides a promising strategy to increase the NPs' residence time on mucosal surfaces, which is expected to decrease the required dose of DTX and reduce its side effects.

Ultrasensitive and Adjustable Nanothermometers Based on Er3+-Sensitized Core@Shell Nanoparticles for Use in the First Biological Window.

In recent years, intensive research has focused on lanthanide-doped nanoparticles (NPs) used as noncontact temperature sensors, particularly in nanomedicine. These NPs must be capable of excitation and emission within biological windows, where biological materials usually show better transparency for radiation. In this article, we propose that NPs sensitized with Er3+ ions can be applied as temperature sensors in biological materials. We synthesized the NPs through a reaction in high-boiling solvents and confirmed their crystal structure and the formation of core@shell NPs by using X-ray diffraction, high-resolution transmission electron microscopy, and element distribution mapping within the NPs. NaErF4@NaYF4, NaYF4:12.5% Er3+, 2.5% Tm3+@NaYF4, NaYF4:7.5% Er3+@NaYF4, and NaYF4:12.5% Er3+, 2.5% Ho3+@NaYF4 exhibited intense upconversion (UC) emission under 1532 nm laser excitation detectable also in the whole human blood. We propose that this UC results from energy transfer between Er3+ ions and from Er3+ to Tm3+ or Ho3+ codopants. To determine the mechanism of UC, we measured the dependence of the emission band intensities on the laser power densities. Importantly, we also analyzed the temperature-dependent emission of the NPs within the 295-360 K range. Based on the collected emission spectra, we calculated the luminescence intensity ratios (LIRs) of the emission bands to assess their potential for optical temperature sensing. The temperature-sensing properties varied with the concentration of Er3+ ions and the presence of additional Tm3+ or Ho3+ codopants. Depending on the NP composition and the emission bands used for luminescence ratio calculations, the maximum relative temperature sensitivity ranged from 4.55%·K-1 to 1.12%·K-1, with temperature resolution between 0.05 and 2.53 K at room temperature. Finally, as proof of using NPs as temperature sensors in biomedicine, we successfully measured the temperature-dependent emission of NaYF4:7.5% Er3+@NaYF4 NPs dispersed in whole blood under 1532 nm excitation. We demonstrated that the ratio of Er3+ ion emission bands changes with temperature, indicating that these NPs have potential applications in temperature sensing within biological environments. We also confirmed the properties of NPs as temperature sensors by measuring the temperature reading uncertainty and the repeatability of the LIR readings during heating-cooling cycles, thereby confirming the excellent properties of the studied systems as temperature sensors.

Effect of Zn, Ti and Sn dopants on the structural, morphological and optical properties of MgO nanoparticles synthesized via green combustion using Persicaria odorata leaves extract

Effect of Zn, Ti and Sn dopants on the structural, morphological and optical properties of MgO nanoparticles synthesized via green combustion using Persicaria odorata leaves extract

Effect of magnetic field on the structural, optical, and electrical properties of CdS nanoparticles in distilled water by using pulsed laser ablation

In this study, we investigated the impact that the incorporation of a magnetic field has on the properties of cadmium sulfide CdS nanoparticles as well as the performance of an n-CdS/p-Si heterojunction photodetector that was developed by the use of the pulsed laser ablation in a liquid method. Nd:YAG laser pulses (1.064 μm, 550 mJ) were utilized to ablate cadmium sulfide CdS nanoparticles in water. The synthesized nanoparticles were shown to have a polycrystalline hexagonal structure, as evidenced by the findings of the X-ray diffraction experiment, the crystallite size for cadmium sulfide CdS decreased from 4.611 nm to 4.518 nm. The lattice constants of cadmium sulfide CdS nanostructures were determined to be a = 4.1302, c = 6.702, and c/a=1.622. The strain and dislocation density of cadmium sulfide CdS exhibited an increase. Images taken from a field emission scanning electron microscope demonstrated the formation of spherical nanoparticles on the surface. A magnetic field was applied, increasing the CdS film's crystallinity. As a consequence of this enhancement, the particle size of the CdS decreased from 25.18 nm to 12.17 nm. A comparison was made between this and the size of the crystallites that appeared when no magnetic field was present. The EDS spectrum of magnetically prepared cadmium sulfide CdS films indicates the presence of Cd and S, and the weight percentage ratios [Cd]/[S], increase from 3.72 to 3.80. The transmission electron microscopy (TEM) pictures of CdS samples that were generated using a magnetic field contained particles of small size with a mean of 10.10 nanometers. From the FT-IR spectra of cadmium sulfide CdS prepared using a magnetic field within 400–4000 cm−1, the peaks (bands) of cadmium sulfide CdS at 617 cm−1 represent the bending vibration of Cd-S. As a result of the influence of a magnetic field, the optical energy gap of CdS nanoparticles increased from 2.30 eV to 2.72 eV, as indicated by the UV-Vis study. From PL emission spectra the values of the energy band gap of cadmium sulfide CdS increased from 2.45 eV at 505.7 to 2.47 eV when a magnetic field was applied. CdS NP films produced under the influence of a magnetic field were identified as having n-type characteristics by Hall effect assessments, Particle mobility was influenced by particle size. The effect of applying a magnetic field on the efficiency of the n-CdS/p-Si photodetector was investigated and analyzed. When a magnetic field was applied during ablation, the responsivity of n-CdS/p-Si heterojunction photodetectors increased from 0.498 A/W to 0.830 A/W at 510 nm. This was the result of the application of the magnetic field.

Effect of pH on the microstructure and antibacterial properties of MgO nanoparticles by microwave-assisted solution combustion

The application of magnesium oxide (MgO) nanoparticles as a candidate material for antibacterial purposes has been limited by their relatively low antibacterial activity. In this study, antibacterial MgO nanoparticles were synthesised in one step using magnesium nitrate and citric acid as raw materials using an economical and environmentally friendly microwave-assisted solution combustion approach, while the effect of the pH of the reaction system (2, 4, and 7) on the structure and antimicrobial properties of the synthesised MgO nanoparticles was investigated. X-ray diffraction (XRD) analysis demonstrated the formation of cubic-phase MgO nanoparticles, and electron microscopy studies confirmed that MgO nanoparticles synthesised at a precursor solution pH of 4 had uniform size distribution with a small microcrystalline size (∼19 nm) and spherical granular morphology. In addition, the results of the plate colony counting method showed that the antibacterial rate of MgO-4 against Gram-negative Escherichia coli (106 CFU/mL) at a sample concentration of 100 μg/mL was as high as 99.86 %, which showed excellent antibacterial performance. These findings provide valuable insights into how to increase the degree of oxygen adsorption on the sample surface to participate in the reaction, as well as a potential method for constructing nanomaterials with high antimicrobial activity.

Surfactant-Free Method to Prevent Gold Nanoparticle Aggregation and Its Surface-Enhanced Raman Scattering Applications.

The introduction of surfactants to stabilize colloidal citrate-reduced gold nanoparticles (prevent aggregation) is usually used in surface-enhanced Raman scattering (SERS) applications. However, the surfactants have many drawbacks for SERS applications, such as increasing the SERS background and blocking surface active sites. Here, we develop a surfactant-free method to stabilize colloidal cit-AuNPs based on alkali regulation, and this method can prevent gold nanoparticle aggregation under different harsh treatments, including ligand modification, centrifugation-based washing/enrichment, and salt addition. The SERS spectra, density functional theory simulation, and ζ potentials of cit-AuNPs indicate that the stability of enhanced cit-AuNPs under alkaline conditions is attributed to both the increased negative charge density (by ∼6 times from pH 7 to 12) and the molecular configuration on the metal surface. Compared with surfactant-based methods, this method can well maintain the inherent optical and interface properties of nanoparticles, avoid the SERS background, and avoid blocking of the surface active site due to the presence of surfactants. This method will enable AuNPs to have a wide range of applications in areas such as highly sensitive SERS sensors.

Curcumin-loaded lignin nanoparticles: Exploring sonication effects on drug loading and particle properties for future biomedical use

The present study investigates the effects of sonication and cross-linker (oxalic acid) concentration on drug loading and the properties of curcumin-loaded lignin nanoparticles. Selected samples were further assessed for their toxicity and antioxidant potential using the eukaryotic model organism Saccharomyces cerevisiae. Transmission electron microscopy analyses revealed the formation of spherical nanoparticles with diameters in the range of 39–49 nm. Differential scanning calorimetry experiments confirmed the encapsulation of curcumin. Factorial experimental design analyses indicated that sonication time, wave amplitude, cross-linker concentration, and their interactions significantly influenced both ζ-potential – from (−37.0 ± 1.7) mV to (−48.4 ± 0.6) mV – and curcumin loading – from (3.70 ± 0.32) % to (7.10 ± 0.57) %. These parameters are critical for biomedical applications as they relate to the clearance of nanoparticles from the human bloodstream and drug dosage optimization. Although sonication has been previously reported for the preparation of lignin nanoparticles, this study represents the first documented instance of manipulating drug loading by controlled sonication parameters. While none of the investigated factors significantly affected the mean particle diameter, observations from TEM micrographs suggest that cross-linker concentration and wave amplitude notably influence nanoparticle morphology. Moreover, the curcumin-loaded nanoparticles exhibited non-toxicity toward Saccharomyces cerevisiae and demonstrated the ability to enhance yeast cell tolerance to H2O2-induced oxidative stress, underscoring their antioxidant potential. Therefore, this research significantly contributes to the scientific understanding of how the control of sonication parameters and cross-linkers can modulate the properties of curcumin-loaded lignin nanoparticles for future biomedical applications.