DLS Analysis Research Articles

Bio‐fabrication of Zinc oxide nanoparticles using Strobilanthes cordifolia: Characterization and evaluation of antioxidant, anti‐cholinergic, anti‐inflammatory and wound healing activities

AbstractStrobilanthes cordifolia has emerged as a promising material in traditional medicine. In this study, we have made an attempt to synthesize zinc oxide nanoparticles derived from S. cordifolia leaf. The team employed a wide range of techniques including UV, FT‐IR, XRD, FE‐SEM with EDAX, HR‐TEM with SAED, DLS, Zeta potential, BET and PZC analysis to thoroughly examine the properties of the NPs. FTIR analysis provided evidence of various functional groups within the NPs. XRD analysis demonstrated the crystal nature and phase purity of the NPs. SEM analysis showcased the spherical shape of the particles, while TEM revealed their rod‐like shape with sizes averaging at approximately 10 nm. DLS analysis indicated the average particle size, and the high zeta potential value confirmed the stability and BET analysis deciphered the specific surface area of the biosynthesized NPs. The NPs confirmed strong antioxidant properties with DPPH, ABTS, and hydroxyl radicals. Enzyme studies confirmed good anti‐cholinergic activity and anti‐inflammatory efficacy, highlighting their potential therapeutic benefits. The NPs demonstrated promising wound healing properties. Overall, this research study sheds light on the medicinal aspects of zinc oxide nanoparticles from S. cordifolia leaf extract and it offers exciting prospects for future exploration and development in this field.

Modified cellulose nanocrystals enhanced polycaprolactone multifunctional films with barrier, UV-blocking and antimicrobial properties for food packaging

The packaging industry demands improved eco-friendly materials with new and enhanced properties. In this context, bio-nanocomposite films with antimicrobial and UV-shielding properties based on modified cellulose nanocrystals/polycaprolactone (MCNC/PCL) were fabricated via solution casting method, and then food packaging simulation was carried out. CNCs were obtained by acid hydrolysis followed by successful functionalization with Quaternary ammonium surfactant, confirmed by FTIR, XPS, XRD, TEM, and DLS analyses. Furthermore, the morphological, physical, antibacterial, and food packaging properties of all prepared films were investigated. Results showed that the mechanical, UV blocking, barrier properties, and antibacterial activity of all composite films were remarkably improved. Particularly, the addition of 3 wt% MCNC increased the tensile strength and elongation at break by 27.5 % and 20.0 %, respectively. Moreover, the permeability of O2, CO2, and water vapor dramatically reduced by 97.6 %, 96.7 %, and 49.8% compared to the Neat PCL. Further, the UV-blocking properties of the composite films were significantly improved. The antimicrobial properties of MCNC/PCL films showed good antimicrobial properties against S. aureus. Finally, cherry packaged with 1 and 3 wt% MCNC films exhibited satisfactory freshness after 22 days of preservation. Overall, the fabricated PCL nanocomposite films can be utilized in the food packaging industry.

Green Synthesis and Characterization of Zinc Oxide Using Carica papaya Leaf Extract

AbstractEnvironmental methodologies are gaining recognition in this modern world. Environmental nanotechnology plays a major role in improving modern fields of environmental engineering and science. Metal oxide nanoparticles have exceptional properties due to their small size, including quantum confinement, surface‐to‐volume ratio, plasmon excitation, high biocompatibility, and surface modifiability. The biosynthesis of nanoparticles using fungi, bacteria, and plants through various biotechnological techniques is currently a new paradigm for environmental protection. Synthesis of nanoparticles through plant extract is good because it eliminates the dangers of toxic chemicals, it is environmentally friendly, simpler, and safer as the reaction time is reduced and it can also be increased in size for higher operation. The present study is based on the development of zinc oxide nanoparticles from papaya leaf extract where zinc nitrate is used as a precursor. The biosynthesized nanoparticles are characterized by X‐ray diffraction, Fourier transform infrared spectroscopy, electron microscopy, energy‐dispersive X‐ray analysis, UV‐visible spectroscopy, and dynamic light scattering analysis. The crystalline phase determination of the zinc oxide nanoparticles is analyzed by X‐ray diffraction and the formation of polycrystalline zinc oxide nanoparticles is confirmed. FT‐IR spectrum reveals the main functional groups and chemical information in zinc oxide nanostructures. Morphological analysis is performed using SEM at different magnification levels. EDAX analysis shows the purity of the composite samples. Optical characterization is performed using a UV–vis spectrophotometer. DLS analysis shows that the nanoparticles formed have a relatively well‐defined dimension.

Evaluation of antimicrobial, antioxidant, and anti-inflammatory abilities of sustainably synthesized Co3O4 NPs

The cobalt oxide nanoparticles (Co3O4 NPs) sustainably synthesized by Citrus tangerina leaf aqueous extract and it was characterized by standard analytical experiments including UV–vis spectra, FT-IR, DLS, and SEM analyses. Furthermore, their antibacterial, antifungal, antioxidant, and anti-inflammatory competence were investigated through in-vitro approach. The aqueous extract derived from C. tangerina leaf has the potential to synthesize the Co3O4 NPs and it was evidenced by peak appeared at 399 nm under UV–vis spectrum study. Furthermore, FTIR analysis results demonstrated that the occurrence of most active functional groups (alcohols (C–O), phenols (C–O), carbonyl (C=O), and amide (CO = )). The DLS and SEM analyses revealed that the average size as well as shape of C. tangerina leaf extract mediated Co3O4 NPs were found as ranging between 90 and 130 nm and octahedral in shape respectively. The C. tangerina leaf fabricated Co3O4 NPs demonstrated dose dependent activity for antibacterial (e.g. S. aureus 6538 > E. coli O157 > K. pneumoniae 342 > B. subtilis 6633 at 200 μg mL−1 concentration), antifungal, antioxidant, and anti-inflammatory assays. The obtained findings conclude that the C. tangerina leaf aqueous extract has the potential to synthesize the Co3O4 NPs and synthesized particle has considerable selective biomedical applications.

Effect of chitosan coating on drug carrier capacity of metal organic framework MIL-100(Fe) contained cyclophosphamide.

In recent years, the field of biomedical engineering, particularly drug delivery, has seen significant advancements in the evaluation of various drug carriers. Metal-organic frameworks (MOFs), are porous materials with strong coordination bonds. They have emerged as a promising tool for enhancing the effectiveness of drug delivery. In this investigation, the effect of chitosan coating on cyclophosphamide loading of MIL-100(Fe) was studied in computational and experimental way. The chitosan-coated MIL-100(Fe) containing cyclophosphamide (MIL-100(Fe)/CS/CP) was characterized by SEM, FTIR, BET, DLS, and powder X-ray diffraction analysis. The drug loading and release process were quantified using UV-spectroscopy. In vivo-In vitro study was performed. The result of drug loading in chitosan-coated MIL-100(Fe) with a drug payload of 32% revealed a significant increase compared with the MIL-100(Fe) with a 26.41% payload. According to the DLS analysis the existence of chitosan increase MIL-100(Fe) particle size (381 to 463nm) and change the zeta potential from 18 to -17mV. The toxic effect of MIL-100(Fe)/CS/CP was determined on human breast cancer (MCF-7) cells. In vivo images and H&E analysis shows inhibition properties of MIL-100(Fe)/CS/CP on tumor cells. The amount of drug loading of MIL-100(Fe) particles and MIL-100(Fe)/CS was simulated using molecular dynamic software LAAMPS. MIL-100(Fe) was synthesized biofriendly at room pressure and temperature with an Iron (II) chloride source coated with chitosan (CS) a natural polysaccharide. Incorporating MIL-100(Fe) with this natural polymer enhanced the drug loading capacity of MIL-100(Fe) and controlled drug release.

Comparative study for enzymatic hydrolysis of sugarcane bagasse using free and nanoparticle immobilized holocellulolytic enzyme cocktail

This study aimed at a comparative analysis of enzymatic hydrolysis of sugarcane bagasse biomass by using a free holocellulase cocktail of an enzyme (Cellic CTec2) and immobilized enzyme system on IOMNP@SiO2-NH2 support to make the process cost-effective. The immobilization was substantiated by examining the nano biocatalysts using FTIR, TEM, and DLS analysis. IOMNP@SiO2 –NH2 and immobilized enzyme system have average particle sizes of 81.1, and 455.9 nm confirmed by DLS. Response surface methodology (RSM) based on the Box Behnken design was employed to optimize the saccharification process conditions. The free cellulase cocktail showed a maximum hydrolysis yield of 70.71 % at 12.5FPU/gm enzyme dose, while the immobilized enzyme at a dose of 20 FPU/gm achieved a conversion rate of 74.19 % under optimized parameters likes hydrolysis time, surfactant and substrate concentration. Pretreated sugarcane bagasse substrate was used to evaluate the reusability potential of magnetically immobilized cellulase enzyme compared to recovered free enzyme up to 5 cycles. In the second and third cycles, the conversion rates of cellulose to glucose were determined to be 68.21 %, and 52.6 %, respectively. The findings of this study demonstrate that the immobilized Cellic CTec2 enzyme cocktail on functionalized IOMNP is effective for hydrolyzing sugarcane bagasse which also provides the advantages of easy recovery and reusability of enzyme for multiple hydrolysis cycles.

Thymol-loaded liposomes effectively induced apoptosis and decreased EGFR expression in colorectal cancer cells.

Colorectal cancer (CRC) is one of the most common and deadly cancers worldwide. Different factors, such as environmental and genetic factors and lifestyle, affect it. Owing to the presence of phenolic, alkaloid, antioxidant, and terpenoid compounds, herbal compounds can be effective in the treatment of various cancers. Thymol is a natural monoterpene phenol that is abundant in some plants and exerts several biological effects. The aim of this study was to investigate the apoptotic, anti-proliferative effect and EGFR gene expression under the influence of thymol-loaded nanoliposome in SW84 and SW111 cell lines derived from colorectal cancer. The lipid thin-film hydration method was used to synthesize thymol-loaded liposomes, and their characterization was performed using TEM, DLS, and HPLC analyses. SW84 and SW1111 cells were treated with thymol- and thymol-loaded liposomes at different doses, the inhibition of cell proliferation was evaluated using an MTT assay, the rate of apoptosis induction was assessed using flow cytometry, and EGFR gene expression was measured using real-time PCR. The nanoparticles produced were spherical, uniform, and 200 ± 10nm in size. HPLC analysis showed that approximately 98% thymol was loaded into the nanoliposome. The results of the MTT assay showed that thymol and thymol-nanoliposomes decreased the proliferation of SW84 and SW1111 cells in a concentration-dependent manner. The IC50 of thymol and thymol-nanoliposomes were 18 and 14.2µg/ml for the SW48 cell line (P = 0.04) and 10.5 and 6.4µg/ml for the SW1116 cell line (P = 0.001). Thymol-nanoliposomes significantly inhibited the proliferation of cancer cells compared to free thymol. Flow cytometry showed an increase in the percentage of apoptotic cells, especially in the thymol-nanoliposome group in the treated cells. Real-time PCR results also showed that thymol and thymol-nanoliposome both caused a decrease in the expression of EGFR genes in both cell lines, but this effect of decreasing gene expression was significantly higher in the thymol-nanoliposome group. Our results showed that thymol-nanoliposomes reduced proliferation, increased apoptosis, and decreased EGFR expression in colorectal cancer-derived cell lines.

Fatty acid profiles of olive oil and moringa oil and their influence on nanoemulsion formation via D-phase emulsification using bakuchiol as a model active compound

Moringa oil (MO) and olive oil (OV) share similar chemical compositions, often considered interchangeable in various applications. However, their behavior in nanoemulsion formation, a widely-used process in the cosmetic industry, remains relatively unexplored. This study aimed to investigate their fatty acid compositions and how they respond to nanoemulsion formation using the D-phase emulsification method. MO comprises approximately 79% oleic acid, 7% palmitic acid, 6% stearic acid, and other minor components. In contrast, OV contains roughly 70% oleic acid, 14% palmitic acid, 10% linoleic acid, and other constituents. In the context of nanoemulsion formation, both oils exhibited similar trends in particle size, polydispersity index (PDI), and zeta potential when varying the formulation compositions. The type of oil significantly influenced particle size at low surfactant concentrations and PDI at higher oil concentrations, consistently affecting zeta potential. The optimal formulation, O1T15G5, yielded droplet sizes of approximately 222 nm (MO) and 50 nm (OV). Both MO and OV nanoemulsions responded similarly to the substitution of oil with bakuchiol (BK), with O0.7B0.3T15G5 achieving the smallest spherical particle size confirmed by TEM and DLS analysis. Encapsulation efficiency and antioxidant activity remained largely unaffected by types of oil. Stability tests at different temperatures showed some distinctions in physical stability but similarities in antioxidant activity stability. The types of oil did not significantly impact BK release or cytotoxicity levels. This research underscores the potential utility of MO as a viable alternative to OV in cosmetic applications, shedding light on their similarities and performance within nanoemulsion formulations.

Synthesis of (10-hydroxycamptothecin intercalated layered zinc hydroxide nitrate)@liposome nanocomposites for improving drug-release performance

A hierarchical nanocomposite of 10-hydroxycamptothecin (HCPT), a nonionic and lipophilic anticancer agent, intercalated layered zinc hydroxide nitrate (LZH) encapsulated in liposomes was fabricated. HCPT molecules were incorporated into sodium cholate (Ch) micelles, and the resulting negatively charged HCPT-loaded Ch micelles were then introduced into the LZH galleries to form an HCPT/Ch intercalated LZH (designated HCPT-Ch-LZH) host-guest nanohybrid. The nanohybrid particles were then coated with liposomes (LSs), resulting in the formation of a core-shell nanocomposite denoted as (HCPT-Ch-LZH)@LS. Using XRD, FT-IR, SEM, TEM, DLS, and elemental analyses, the obtained samples were characterized. Particular attention was paid to the effect of liposome-coating on the HCPT-Ch-LZH's water solubility and drug release. The results demonstrate that the nanocomposite has superior water dispersity and enhanced drug sustained-release performance compared to HCPT-Ch-LZH, indicating that the liposome-coating of drug-LZH nanohybrids is an effective strategy for improving their water dispersity and sustained-release performances. This study presents an efficient strategy for constructing LZH-based drug delivery systems for nonionic and lipophilic medicines.

Improvement of biohydrogen production from rice straw hydrolysate by green-self-prepared nano-silica

Rice straw stands as a highly sustainable agricultural residue enriched in silica and carbohydrates. This study delves into the potential of rice straw, focusing on the impact of green-synthesized nano-silica particles on biohydrogen fermentation using Enterobacter aerogenes. Rice straw was subjected to three different leading pretreatments, i.e., organsolv, sulfuric acid, and sodium hydroxide, to decimate the lignocellulosic structure. In addition to these, sodium hydroxide was employed as a secondary pretreatment for the organosolv- and sulfuric acid-pretreated straw. Three distinct nano-silica particles were extracted from the liquor of alkali pretreatments and examined using XRD, XRF, FE-SEM, and DLS analysis. The solid fractions of pretreatment were enzymatically hydrolyzed and subjected to dark fermentation, achieving the maximum biohydrogen yield of 156.9 ± 2.0 mL per g total solids (TS) from the organosolv-sodium hydroxide pretreated straw. Further improvement of biohydrogen yield to 178.3 ± 4.2 mL per g TS was obtained by adding 200 ppm of nano-silica particles isolated from one-step sodium hydroxide pretreatment. Analyzing the metabolic products exhibited that nano-silica particles modified the metabolic pathway, leading to an increase in acetic acid production and a decrease in ethanol production. It was concluded that nano-silica particles isolated from untreated and treated rice straws have the potential to boost biohydrogen generation. However, the degree of improvement was dependent on the composition and structure of the nanoparticles.

Sequestration of zirconium and hafnium content using magnetic cellulose/chitosan nanocomposites from waste effluents

New Magnetic nanocomposites containing biological polymer (i.e. chitosan and cellulose) as reinforcers were synthesized. Successful fabrication of the magnetic cellulose-chitosan (MCCh) nanocomposites with norvaline (MCCh-N) and 8-hydroxyquinoline (MCCh-8H), respectively were achieved and investigated as a zirconium and hafnium ions adsorbent in aquatic media. The felicitous synthesis was confirmed using FTIR, TGA, TEM, DLS, XRD, SEM-EDX, and BET analyses. The nanocomposites (MCCh-N and MCCh-8H) performance was evaluated under different conditions of adsorbent dose (0.01–0.1 g), Zr(IV) and Hf(IV) initial concentration (100–500 mg/L), pH (1.0–2.5), temperature (~25–55 °C), and time (~10–120 min). The adsorption process of both metal ions on the prepared nanocomposites was modeled using Langmuir, Freundlich, Temkin, and D-R models. The elimination of Zr(IV) and Hf(IV) by MCCh-N and MCCh-8H followed a pseudo-second-order kinetic model (R2 = 0.998, 0.997 and 0.998, 0.999), respectively. Furthermore, kinetic, thermodynamic, and reusability studies were conducted to evaluate the behavior and adsorption mechanism of Zr(IV) and Hf(IV) on the surface of MCCh-N and MCCh-8H nanocomposite.All in all, the high removal capturing and recovering zirconium and hafnium ions from laboratory wastewater and waste solution resulting from the leaching process of the Abu Rusheid concentrate sample make MCCh-N and MCCh-8H potential adsorbents for in situ treatment of zirconium and hafnium ions-containing aqueous solutions.

Synthesis and characterization of silver nanoparticles loaded with carboplatin as a potential antimicrobial and cancer therapy

In recent studies with silver nanoparticles, it has been reported that the use of nanoparticles in carrier drug systems increases tumor suppression and reduces drug-related side effects. At the same time, the combination of traditional medicine with nanotechnology provides the opportunity to develop new antimicrobial agents. The aim of this study was to determine the anticancer, antimicrobial activities and pro-apoptotic effects of silver nanoparticles (AgNPs), and carboplatin-loaded silver nanoparticles (AgNPs-Car). Characterization studies of the synthesized nanoparticles were carried out by DLS, EDX-STEM, and FTIR analysis. The antiproliferative and pro-apoptotic effects of these molecules were evaluated using XTT and Annexin V, respectively. MIC (Minimum Inhibitory Concentration) test was used to determine the antimicrobial activity. The anticancer activity of the AgNPs-Car was high in MCF-7 (human breast adenocarcinoma), A549 (human lung carcinoma), and C6 (brain glioma) cells. The cell group with the most effective selective cytotoxic activity was C6 cells. It was also shown that AgNPs-Car and AgNPs induced DNA fragmentation eventually increasing apoptosis of cells. The antimicrobial activity of AgNPs and AgNPs-Car was evaluated on Gram-positive and Gram-negative pathogenic microorganisms and yeast fungi. Among the nanomaterials that reached effective MIC values according to reference sources, AgNPs-Car achieved better results. As a result, AgNPs-Car was found to be very successful in targeting C6 glioma cells by facilitating cell entry of the drug. In addition, their anticancer activity on MCF-7 and A549 cells was high and their toxicity was low. Silver nanoparticles are preferred for creating a better drug carrier system because of their qualitative properties and effects. Therefore, it is an interesting field for research on targeting cancer cells and pathogenic microorganisms.

The urolithin B nanomicellar delivery system as an efficient selective anticancer compound.

Urolithin B (UB), the antioxidant polyphenol has a protective impact on several organs against oxidative stress. However, its bioactivity is limited by its hydrophobic structure. In the current study, UB was encapsulated into a liposomal structure to improve its bioactivities anticancer, and antimicrobial potential. The UB nano-emulsions (UB-NE) were synthesized and characterized utilizing FESEM, DLS, FTIR, and Zeta-potential analysis. The UB-NMs' selective toxicity was studied by conducting an MTT assay on MCF-7, PANC, AGS, and ASPC1 cells. The AO/PI analysis verified the UB-NMs' cytotoxicity on ASPC1 cell lines and approved the MTT results. Finally, the antibacterial activity of the UB-NMs was studied on both gram-positive (B. subtilis, S. aureus) and gram-negative (E. Coli, P. aeruginosa) bacteria by conducting MIC and MBC analysis. The 68.15nm UB-NMs did not reduce the normal HDF cells' survival. However, they reduced the cancer cells' (PANC and AGS cell lines) survival at high treatment concentrations (> 250µg/mL) compared with normal HDF and cancer MCF-7 cells. Moreover, the IC50 doses of UB-NMs for the ASPC1 and PANC cancer cells were measured at 44.87, and 221.02µg/mL, respectively. The UB-NMs selectively exhibited apoptotic-mediated cytotoxicity on the human pancreatic tumor cell line (ASPC1) by down-regulating BCL2 and NFKB gene expression. Also, the BAX gene expression was up-regulated in the ASPC1-treated cells. Moreover, they exhibited significant anti-bactericidal activity against the E. coli (MIC = 50µg/mL, MBC = 150µg/mL), P. aeruginosa (MIC = 75µg/mL, MBC = 275µg/mL), B. subtilis (MIC = 125µg/mL, MBC = 450µg/mL), and S. aureus (MIC = 50µg/mL, MBC = 200µg/mL) strains. The significant selective cytotoxic impact of the UB-NMs on the human pancreatic tumor cell line makes it an applicable anti-pancreatic cancer compound. Moreover, the antibacterial activity of UB-NMs has the potential to decrease bacterial-mediated pancreatic cancer. However, several bacterial strains and further cancer cell lines are required to verify the UB-NMs' anticancer potential.

A novel nanoemulsion based on clove and thyme essential oils: Characterization, antibacterial, antibiofilm and anticancer activities

BackgroundEssential oil nanoemulsions have received much attention in the last period due to their ability to fight microbes and cancers. In the current study, clove and thyme essential oils CL+TH-emulsion and CL+TH-nanoemulsion were prepared through an eco-friendly method. The prepared CL+TH-nanoemulsion was characterized using DLS and TEM analyses. ResultsResults revealed that CL+TH-nanoemulsion droplets were spherical in shape and nanoform in size (68.6 nm) with PDI 0.281. MIC concentrations of CL+TH-nanoemulsion against tested bacteria were found to be between 6.25 and 25 mg/mL. After being exposed to MICs of CL+TH-emulsion and CL+TH-nanoemulsion, which additionally prompted 1.43 log and 3.12 log declines, accordingly, as opposed to untreated (Control), the number of cells grown in the generated biofilms decreased. Furthermore, CL+TH-nanoemulsion exhibited anticancer activity more than CL+TH-emulsion toward HepG2 and MCF-7. Also, the effect of CL+TH-nanoemulsion is more effective and significantly cytotoxic than taxol on MCF-7. Besides, both prepared emulsions increased the rate of apoptosis and decreased the cell viability % of MCF-7 by increasing the activity of caspases 8 and 9. Moreover, CL+TH-nano emulsion decreased the activity of VEGFR-2 in MCF-7 in a more pronounced manner than CL+TH-emulsion and taxol. ConclusionsThe prepared CL+TH-nanoemulsion had antibacterial, and antibiofilm as well as anticancer properties, which can be used in different biomedical applications after extensive studies in vivo.How to cite: Hashem AH, Doghish AS, Ismail A, et al. A novel nanoemulsion based on clove and thyme essential oils: Characterization, antibacterial, antibiofilm and anticancer activities. Electron J Biotechnol 2024;68. https://doi.org/10.1016/j.ejbt.2023.12.001.

Highly selective and sensitive recognition of multi-ions in aqueous solution based on polymer-grafted nanoparticle as visual colorimetric sensor

A novel, selective and sensitive colorimetric sensor for naked-eye detection and adsorption of multi-ions in aqueous solution was synthesized using hybridization of organic–inorganic phase. The polymer-grafted nanoparticles (PGNPs) was synthesized via atom transfer radical polymerization (ATRP) of monomers on modified TiO2 NPs and applied under optimized conditions for naked-eye detection: sensor mass: 15 mg; response time: 30 s with limits of detection (LODs) as small as 10, 1, 0.5, and 1 ppb Hg (II), Cd (II), Cu (II), and UO2 (II) at pH = 8, 9, 6, and 7, respectively. The efficient selectivity of the naked eye sensor to multi-ions in the presence of various ions was affirmed wherein the color of the chemosensor in the presence of Hg (II), Cd (II), Cu (II), and UO2 (II) shifted from gray to violet, orange, green and yellow, respectively. The salient advantages of this method comprise expeditious, selectable, high reproducibility, with reasonable adsorption capacity (133 mg g-1) and inexpensive nature for rapid detection of heavy metal ions contamination in aqueous solution in an inexpensive manner. The adsorption mechanism was studied via adsorption kinetics and adsorption isotherm models and the accuracy of the chemosensor has been confirmed and supported by XRD, FT-IR, TGA, 1H-NMR, SEM, TEM, EDX mapping, DLS, BET, and EDS analysis.

Lawsonia inermis plant-based cobalt oxide nanoparticles: Synthesis, characterization and their biological studies

In the current study synthesized Cobalt oxide nanoparticles (Co3O4 NPs) using Lawsonia inermis plant extract as fuel. The synthesized Co3O4 NPs were characterized using UV–visible spectroscopy, DLS, FT-IR, XRD, FESEM, and EDX analysis. The synthesized Co3O4 NPs were confirmed by the XRD analysis and their average size was determined using DLS and FESEM analysis. The average size of the cobalt oxide nanoparticles obtained from FESEM analysis was found to be around 98 nm and strong signals of cobalt were captured in EDX images. The synthesized Co3O4 NPs were tested on bacterial and fungal strains of three concentrations viz 50, 100 and 170 ppm. An increase in the concentration of Co3O4 NPs shows potent antibacterial and antifungal activities. The higher concentration (170 ppm) showed good antimicrobial activity on all strains of bacteria and fungi than the lower concentrations (50 and 100 ppm) of Co3O4 NPs. The observed zone of inhibition values against all bacteria and fungi ranged from 0.3 to 3.0 mm and 20 ± 0.42 mm to 0.3 to 2.9 mm, respectively. Among them, Staphylococcus and Streptococcus aureus showed more zones of inhibition at 170 ppm concentration. Meyerozyma guilliermondii fungal strain showed more zone of inhibition at 170 ppm concentration.

Different morphologies of super-balls obtained to form photonic crystals of cholesteryl benzoate liquid crystals.

The current study highlights the synthesis and characterization of some nanocomposite materials formed by polymer particles and liquid crystals. The liquid crystals used were cholesteryl benzoate (CLB), and the particles were synthesized by emulsion polymerization in the absence of the emulsifier. Through SEM and DLS analysis, the synthesis of particles of the same size was emphasized, and the amount of CLB showed no influence on these parameters. The lack of signal for CLB in the case of DSC and XRD analyses for the sample with the smallest amount of liquid crystal is attributed to the detection limits of the devices. To complete the surface characterization of the particles, XPS analysis was performed. Through XPS it was underlined that in the case of the smallest amount and the largest amount of CLB, respectively, it is encapsulated in the polymer particles, unlike the case of the average amount used, in which core-shell type morphologies have been obtained. For the electrical characterization of the samples, a Vector Network Analyzer (VNA) connected to two rectangular X-band (i.e., 8.2-12.4 GHz) waveguides through coaxial cables was used.

Fabrication of cationic microgels doped MnO2/Fe3O4 nanocomposites, and study of their photocatalytic performance and reusability in organic transformations

AbstractThis article reports, the fabrication of cationic microgel doped MnO2/Fe3O4 nanocomposites (CM@MnO2/Fe3O4) via free radical emulsion polymerization technique, and an economical and environmental friendly approach to some organic transformations, such as heterogeneous photocatalytic reduction of methylene blue (MB, toxic dye), para‐nitro phenol (PNP, harmful pollutant) and dimethyl amino benzaldehyde (DMAB, skin allergic reagent) in presence of UV light (38 W). First of all, three different crosslinked grades of cationic microgels (CMs) have been synthesized by using styrene, dimethyl acrylamide, cyclohexyl methacrylate, [2‐(acryloyloxy)ethyl] trimethylammonium chloride and N‐hydroxymethyl acrylamide monomers by taking different amounts of N‐hydroxymethyl acrylamide, and keeping the other monomers in fixed quantities. Further, all the grades of CMs have been doped by bimetallic MnO2/Fe3O4 nanoparticles, through hydrothermal method. Fabrication of CMs and CM@MnO2/Fe3O4 nanocomposites has been confirmed by the characteristic peaks observed in FT‐IR spectral analysis and their thermal stability has been evidenced by thermogravimetric analysis. TEM and DLS analyses have revealed their particular size. The surface morphology of CMs and CM@MnO2/Fe3O4 nanocomposites has been visualized by scanning electrode microscope analysis. The nanocomposites have effectively and efficiently catalyzed the reduction reactions of MB, PNP, and DMAB, in presence of UV light, by 98%, 98%, and 86%, respectively. The photocatalysts have been reused up to eight cycles without any loss of their catalytic activity. The photocatalytic reductions have also been studied for their kinetics, and exhibited pseudo first order kinetics (kapp, 10−2 min−1).

Dopamine sensing by fluorescent carbon nanoparticles synthesized using artichoke extract.

The practical and easy detection of dopamine levels in human fluids, such as urine and saliva, is of great interest due to the correlation of dopamine concentration with several diseases. In this work, the one-step synthesis of water-soluble carbon nanoparticles (CNPs), starting from artichoke extract, containing catechol groups, for the fluorescence sensing of dopamine is reported. Size, morphology, chemical composition and electronic structure of CNPs were elucidated by DLS, AFM, XPS, FT-IR, EDX and TEM analyses. Their optical properties were then explored by UV-vis and fluorescence measurements in water. The dopamine recognition properties of these CNPs were investigated in water through fluorescence measurements and we observed the progressive enhancement of the CNP emission intensity upon the progressive addition of dopamine, with a binding affinity value of log K = 5.76 and a detection limit of 0.81 nM. Selectivity towards dopamine was tested over other interfering analytes commonly present in human saliva. Finally, in order to perform a solid point of care test, CNPs were adsorbed on a solid support and exposed to different concentrations of dopamine, thus observing a pseudo-linear response, using a smartphone as a detector. Therefore, the detection of dopamine in simulated human saliva was performed with excellent results, in terms of selectivity and a detection limit of 100 pM.

A deeper insight into the evaluation of water-in-oil amicroemulsion templated samarium sulfide nanospheres: exploring its role in pickering emulsion formulation for photocatalytic dye degradation and synthesis of PANI@Sm2S3 nanocomposites.

This study examines the effectiveness of W/O microemulsion-mediated Sm2S3 nanospheres in pickering emulsion-based crystal violet (CV) dye degradation and PANI@Sm2S3 nanocomposite synthesis. The evaluation of nanospheres inside the core of reverse micelles was performed through DLS, TEM and FESEM analyses. The formation of nanospheres involve two phases: a nucleation phase (5-30 min) and growth phase (30-120 min). Through in situ hydrophobization of negatively charged (with a zeta value of -4.47 mV at neutral pH) Sm2S3 nanoparticles (0.1 wt%) with a suitable amount of a cationic CTAB surfactant, a stable O/W pickering emulsion was developed. 0.1 wt% Sm2S3in situ hydrophobized with 2.7 mM CTAB offered a stable pickering emulsion with a diameter of 23 μm after 1 day of storage. This pickering emulsion improves the local concentration of CV by efficiently encapsulating dye molecules inside the core of emulsion droplets. Therefore, dye molecules get numerous opportunities to interact with the Sm2S3 photocatalyst and efficiently degrade. The pickering emulsion stabilised by 0.1 wt% of Sm2S3 nanoparticles in situ hydrophobized with 2.7 mM of CTAB results in almost 100% degradation. Moreover, using only solid Sm2S3 (having wt% of 0.025 or 0.075) as a pickering stabiliser, new PANI@Sm2S3 spherical nanocomposites were synthesised via pickering emulsion polymerization. The formation of PANI@Sm2S3 composites was identified via UV-vis, IR, and 1H-NMR investigations. The analysis of FESEM images showed that the amount of nanoparticles used in the dispersion (for 0.025 wt%, 35 nm and 0.075 wt%, 29 nm) strongly influences the size and shape of the composites.