Fourier Transmission Infrared Research Articles

Copper nanoparticles biosynthesis by Stevia rebaudiana extract: biocompatibility and antimicrobial application

The growth of material science and technology places a high importance on the creation of better processes for the synthesis of copper nanoparticles. So that, an easy, ecological, and benign process for producing copper nanoparticles (CuNPs) has been developed using candy leaf (Stevia rebaudiana) leaves aqueous extract for the first time. UV-visible spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), high-resolution transmission electron microscope (HR-TEM), Fourier transmission infrared (FTIR), and zeta potential were applied to demonstrate strong characterization for the biosynthesized stevia-CuNPs. The UV-visible absorbance at 575 nm of surface plasmon resonance (SPR) was 1.2. The particle size mean diameter was recorded as 362.3 nm with − 10.8 mV zeta potential. The HR-TEM scanning revealed 51.46–53.17 nm and spherical-shaped stevia-CuNPs surrounded by coat-shell proteins. The cytotoxicity and cytocompatibility activity assay revealed that stevia-CuNPs was safe in lower concentrations and had a significant cell viability reduction in higher concentrations. The produced stevia-CuNPs were applied as antimicrobial agents against eight pathogenic bacteria and five fungi strains. The inhibitory action of the stevia-CuNPs was more pronounced in bacteria than in fungi, and they likewise demonstrated further inhibition zones in Staphylococcus aureus (50.0 mm) than in Aspergillus flavus (55.0 mm). With inhibition zone sizes of 50.0 mm and 47.0 mm and 50 µg/ml minimum inhibitory concentration, S. aureus and A. flavus were the most inhibited pathogens. The minimum lethal effect (MLC) estimate for S. aureus was 50 µg/ml, whereas 75 µg/ml for A. flavus. The stevia-CuNPs mode of action was characterized as bactericidal/fungicidal as the ratio of MIC to MLC was estimated to be equal to or less than 2. After all, stevia-CuNPs could be used as an alternative to commercial antibiotics to solve the problem of multidrug-resistant (MDR) microorganisms.

Structural characterization and evaluation of mycogenic zinc oxide nanoparticles from the cell-free culture-extract of <i>Aspergillus niger</i>

Advances in the biological synthesis of nanoparticles have attracted decisive research attention in recent years. This is due to their eco- friendliness, nontoxicity and large spectra of applications. In this work, the structural characteristics and the purity of biogenic zinc oxide (ZnO) nanoparticles were assessed. Zinc oxide (ZnO) nanoparticles were synthesized extracellularly using the culture filtrate of Aspergillus niger, in the presence of zinc acetate dihydrate, as a precursor. The structural characteristics and purity of the nanoparticles were examined using standard characterization methods viz UV-visible spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transmission infrared (FT-IR) spectroscopy and X-ray diffraction (XRD). Results revealed a peak at 311nm and whitish and spherical particles with particulate sizes between 30 and 40 nm for the UV- -1 visible spectroscopy and SEM respectively. On the FT-IR scale, absorption peaked at 548 cm in the spectra region known for the functional groups of ZnO nanoparticles; while the average crystalline size was 21 nm based on XRD analysis. Findings in this study revealed that the ecofriendly biogenic nanoparticles synthesized by common fungi, such as Aspergillus niger, possess desirable qualities comparable to those from non-ecofriendly and costly chemical processes, which are currently employed for an array of applications.

Catalytic effect of N-phenylaminopropyl polyheadral oligomeric silsesquioxane in the synthesis of hybrid nanocomposites based on polycyanurate

Organic-inorganic nanocomposites based on heat-resistant crosslinked polycyanurate (PCN) and N-phenylaminopropyl polyhedral oligomeric silsesquioxane (NPAP-POSS), containing eight reactive secondary amino groups, were synthesized using the in situ reactive formation method. Fourier transmission infrared (FTIR) spectroscopy and dynamic differential scanning calorimetry (DSC) methods were used to study the effect of NPAP-POSS on the kinetics of bisphenol E dicyanate ester (DCBE) polycyclotrimerization during the formation of PCN in PCN/NPAP-POSS nanocomposites. The content of the nanofiller was varied from 0.05 to 1.00 wt.%. Based on the results of FTIR spectral studies, the main kinetic peculiarities of PCN formation were found and their changes under the action of NPAP-POSS nanofiller were determined. A significant catalytic effect of NPAP-POSS on the polycyclotrimerization of DCBE was found, which is confirmed by a decrease in the time of the onset of auto-acceleration, an acceleration of the conversion of cyanate groups of DCBE and the formation of triazine cycles of PCN, an increase in the values of the maximum reaction rate, a decrease in the duration of the reaction, etc. The dynamic DSC method also confirmed the catalytic effect of NPAP-POSS on the formation of PCN in the nanocomposites and established the main kinetic characteristics depending on the content of the nanofiller: a significant decrease in the temperature of the exothermic maximum, an increase in the reaction enthalpy, non-monotonic changes in the induction period and reaction rate, etc. From the analysis of the experimental data, it was concluded that the detected changes in the kinetics of the in situ reaction formation of PCN/NPAP-POSS nanocomposites and the recorded catalytic effect of the nanofiller are due to the fact that two chemical processes occur during the synthesis of the nanocomposites: chemical interaction of –O–C≡N groups of DCBE with secondary –NH groups of NPAP-POSS, which led to further embedding of nanoparticles into the resulting polymer matrix and the direct polycyclotrimerization of DCBE with formation of hybrid polycyanurate network. Schemes of the sequential reactions explaining the catalytic effect of the nanofiller in the synthesis of hybrid PCN/NPAP-POSS nanocomposites are proposed. It was concluded that under the selected conditions of the synthesis, the greatest catalytic effect of the nanofiller is manifested at its content of 0.10 wt.%, since for this sample the maximum shift of the reaction exothermic peak towards lower temperatures, the maximum reaction rate, and the minimum induction period and reaction start temperature were recorded. The results of the research make it possible to optimize the synthesis of heat-resistant materials promising for use in special-purpose structures.

Augmented reparative potential of adipose-derived stem cells with silver nanoparticles against CCl4-induced liver injury in rats

Cymbopogon citratus (lemongrass) is a widely used medicinal plant. The previous literature studies demonstrated its diverse pharmacological activities such as anti-inflammatory, anti-diabetic, antibacterial and antifungal properties. The present study involves the green synthesis of silver nanoparticles from lemongrass and their characterization by X-ray diffraction (XRD), scanning electron microscope (SEM) and Fourier transmission infrared (FTIR). The purpose of this study is to evaluate the hepatoprotective potential of silver nanoparticles derived from the aqueous extract of lemongrass (LG-NPs) in comparison with the rat adipose-derived mesenchymal stem cells (ASCs) treated with lemongrass-derived silver nanoparticles (LG-NPs + ASCs). To assess the hepatoprotective effect of LG-NPs + ASCs, CCl4-induced fibrosis model rats were employed and it was revealed that transplanting LG-NPs + ASCs decreased fibrosis development compared to transplanting naive ASCs and LG-NPs, as demonstrated by improved hepatic architecture and functions. Additionally, the liver parenchyma's expression of fibrosis-associated gene markers Interleukin 1 beta (IL-1β), Cytochrome P450 2E1 (CYP2E1), Transforming Growth Factor Beta 1 (TGF-β1), collagen type I alpha 1(Col1α1), α-smooth muscle actin (α-SMA) reduced after LG-NPs + ASCs transplantation. These results suggest that pretreating ASCs with LG-NPs increase their effectiveness.

Green Synthesis of Novel Silver Nanoparticles Using Salvia blepharophylla and Salvia greggii: Antioxidant and Antidiabetic Potential and Effect on Foodborne Bacterial Pathogens.

In the face of evolving healthcare challenges, the utilization of silver nanoparticles (AgNPs) has emerged as a compelling solution due to their unique properties and versatile applications. The aim of this study was the synthesis and characterization of novel AgNPs (SB-AgNPs and SG-AgNPs, respectively) using Salvia blepharophylla and Salvia greggii leaf extracts and the evaluation of their antimicrobial, antioxidant, and antidiabetic activities. Several analytical instrumental techniques were utilized for the characterization of SB-AgNPs and SG-AgNPs, including UV-visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transmission infrared (FT-IR) spectroscopy, energy-dispersive X-ray analysis (EDX), and X-ray diffraction (XRD). FTIR analysis identified various functional groups in the leaf extracts and nanoparticles, suggesting the involvement of phytochemicals as reducing and stabilizing agents. High-resolution TEM images displayed predominantly spherical nanoparticles with average sizes of 52.4 nm for SB-AgNPs and 62.5 nm for SG-AgNPs. Both SB-AgNPs and SG-AgNPs demonstrated remarkable antimicrobial activity against Gram-positive bacteria Staphylococcus aureus and Listeria monocytogenes and Gram-negative bacteria Salmonella typhimurium and Escherichia coli. SB-AgNPs and SG-AgNPs also exhibited 90.2 ± 1.34% and 89.5 ± 1.5% DPPH scavenging and 86.5 ± 1.7% and 80.5 ± 1.2% α-amylase inhibition, respectively, at a concentration of 100 μg mL-1. Overall, AgNPs synthesized using S. blepharophylla and Salvia greggii leaf extracts may serve as potential candidates for antibacterial, antioxidant, and antidiabetic agents. Consequently, this study provides viable solutions to mitigate the current crisis of antibiotic resistance and to efficiently combat antimicrobial infections and Type 2 diabetes.

Effect of autoclaving on the dimensional stability and surface characteristics of 3D printed PVDF composite-based implants

In the past decade, a lot of work has been reported on the use of polyvinylidene fluoride (PVDF) based thermoplastic composites as energy storage devices, and implant materials. But hitherto little has been reported on the dimensional stability and surface characteristics of 3D-printed PVDF composites after autoclaving for implant applications. In this study, the effect of autoclaving on surface characteristics (Shore-D hardness, surface roughness (Ra), morphological characteristics), and dimensional stability of 3D printed PVDF-hydroxyapatite (HAp)- chitosan (CS) composite has been reported for implant applications. The signal-to-noise (S/N) ratio approach was used to ascertain the best setting of process parameters for 3D printing by fused filament fabrication (FFF) process. This study suggests that the best setting for the FFF process, for the 3D printing of PVDF composite (90%PVDF-8%HAp-2%CS) are the nozzle temperature (NT) of 225°C, raster angle (RA) 0°, and printing speed (PS) 40 mm/s, resulting in Shore-D hardness 48.5 HD (before autoclaving) and 55.0 HD (after autoclaving), dimensional deviation 0.01 mm (after autoclaving). The results are supported by scanning electron microscopy (SEM) and Fourier transmission infrared (FTIR) spectroscopy analysis.

Green synthesis and characterization of silver and copper nanoparticles and their use as an effective adsorbent for chromium removal and recovery from wastewater.

Chromium (Cr) is one of the hazardous heavy metals that is naturally carcinogenic and causes various health problems. Metallic nanoparticles such as silver and copper nanoparticles (Ag NPs and Cu NPs) have gained great attention because of their unique chemical, physical, and biological attributes, serving diverse and significant role in various useful and sustainable applications. In the present study, both of these NPs were synthesized by green method in which Azadirachta indica plant extract was used. These nanoparticles were characterized by using advanced instrumental techniques such as Fourier transmission infrared (FTIR), X-ray diffraction (XRD), scanning electron microscope attached with energy-dispersive spectroscopy (SEM-EDS), and elemental mapping. These environmentally friendly nanoparticles were utilized for the batch removal of Cr from the wastewater. For analysis of adsorption behaviour, a range of kinetic isotherm models (Freundlich, Temkin, Dubinin, and Langmuir) and kinetic models (pseudo-first-order and pseudo-second-order) were used for the Cu-NPs and Ag-NPs. Cu NPs exhibited the highest Cr removal efficiency (96%) within a contact time of 10-15 min, closely followed by Ag NPs which achieved a removal efficiency of 94% under the similar conditions. These optimal outcomes were observed at a sorbent dose of 0.5 g/L for Ag NPs and 0.7 g/L for Cu NPs. After effectively capturing Cr using these nanoparticles, the sorbates were examined through SEM-EDX analysis to observe how much Cr metal was attached to the nanoparticles, potentially for future use. The analysis found that Ag-NPs captured 18% of Cr, while Cu-NPs captured 12% from the aqueous solution. More precise experimental conditions are needed for higher Cr removal from wastewater and determination of the best conditions for industrial-level Cr reuse. Although nanomaterial exhibit high efficiency and selectivity for Cr removal and recovery from wastewater, more research is necessary to optimize their synthesis and performance for industrial-scale applications and develop efficient methods for Cr removal and recovery.

Remediation of hydrocarbons and metals by hydrocarbon utilizing Pseudomonas taiwanensis YSA-17 isolated from soil contaminated with petroleum.

Careless handling of petroleum in petrochemical industries releases toxic hydrocarbons and metals to soil and water. The aim of the present study was to isolate hydrocarbon-utilizing and metal-tolerant bacteria. Hydrocarbon-utilizing bacteria from petroleum-contaminated soils were isolated on the Bushnell Hass medium. Hydrocarbon degradation by Pseudomonas taiwanensis strain YSA-17 was observed by gas chromatography-mass spectrometry. Bioaccumulation of metals by strain YSA-17 was assessed in nutrient broth. Among different strains, YSA-17 showed the highest potential for hydrocarbon utilization. After 20 days of incubation, YSA-17 completely degraded one compound and during its degradation, there was the formation of 13 new compounds which were absent in uninoculated control. Results of scanning electron microscope and Fourier transmission infrared (FTIR) indicated degradation of hydrocarbons. FTIR showed the formation of new functional groups in YSA-17 inoculated medium. Expression of the total quantity of hydrocarbon-degrading gene (AlkB and NehAc) in petroleum-amended nutrient broth inoculated with strain YSA-17 enhanced significantly during 20 days of incubation compared to control. YSA-17 also significantly removed metals. This study concluded that bioinoculant can be utilized for the bioremediation of pollutants cocontaminated with hydrocarbons and metals. Petroleum-contaminated soil will be remediated for pollutants.

Significant impact of co-doping Eu-doped ZnO nanoparticles with Li on structural–optical properties relationship

ABSTRACT We describe here the structural evolution and optical properties of co-doping of Eu-doped ZnO nanoparticles with lithium synthesized by the sol-gel process. The characterization was carried out via X-ray diffraction (XRD), Fourier transmission infrared (FTIR), UV-Vis spectroscopy, and photoluminescence (PL) techniques. XRD confirmed hexagonal wurtzite phase of ZnO nanoparticles with crystallite size in the range of 22–61 nm. The band gap calculated from UV-vis spectra was in the range of 3.30–3.26 eV for undoped and Li and Eu co-doped ZnO nanoparticles, respectively, while photoluminescence study indicated that Li in Eu-ZnO affected the PL emission intensity, which was attributed to defects present in the crystal lattice. The field emission scanning electron microscopy (FESEM) images revealed the diverse morphology containing, spherical, tri-, tetra-, penta- and hexagonal rod-like nanostructures.

Electrooxidation of Toxic Sulfite Material Using Ni-Ru-Based Heterometallo Supramolecular Polymer as Electrocatalyst: Synthesis and Kinetics Study

Considering the adverse effect of sulfite (SO3 2−), an effective Ni(II)- and Ru(II)-based heterometallic-supramolecular polymer (HMSMP) (polyNiRu) has been synthesized. PolyNiRu was characterized by Field-emission scanning electron microscopy (FE-SEM), and Fourier transmission infrared (FT-IR) spectroscopy. The formation of HMSMP was confirmed via UV–Vis spectroscopy. The molecular weight of polyNiRu (4.77 × 105 Da) was measured through intrinsic viscosity measurement following Mark-Houwink equation. The electrochemical behavior of polyNiRu modified glassy carbon electrode (polyNiRu_GCE) was investigated via CV and DPV. Furthermore, we have investigated the Tafel plot for this heterogeneous electrochemical system to calculate the number of transferred electrons during redox reactions. The limit of detection was found as 0.25 μM with a wide linear dynamic range of 10 to 600 μM. A probable surface mechanism has been studied toward SO3 2− oxidation at the interface of polyNiRu_GCE. Using the Butler-Volmer equation, the heterogeneous kinetic rate transfer constant and charge transfer coefficient were found as 1.02 × 10−6 cm2 s−1 and 0.68 respectively. These obtained parameters were further evaluated by simulated CV, which agreed with the experimental value. Excellent recovery with lower relative standard deviation (RSD) and high stability for 4000 s in analytic solution confirmed the reliability of using this polyNiRu_GCE in the practical assessment.

Electrochemical Detection of Sulfite Using Ni-Ru-Based Heterometallo-Supramolecular Polymer

We have fabricated a Ni (II)-Ru(II)-based heterometallo-supramolecular polymer (HMSMP)-modified glassy carbon electrode for the selective and sensitive electrochemical detection of sulfite (SO3 2-). The modified electrode (polyNiRu/GCE) was characterized by using scanning electron microscopy (SEM) and fourier transmission infrared (FT-IR) spectroscopy. Molecular weight of synthesized polymer (4.77 × 105 Da) was measured through intrinsic viscosity measurement following Mark-Houwink equation. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to investigate the electrochemical behavior of the modified electrode. The modified electrode showed high sensitivity of 0.06 µAµM-1cm-2 for SO3 2-. The detection limit (S/N = 3) for SO3 2- was 0.97 µM with a linear range of 10 to 1000 µM. The developed sensor was successfully examined for real sample analysis with tap water. Excellent recovery with lower relative standard deviation (RSD) and high stability for 4000s in analytic solution confirmed the reliability of using this polyNiRu/GCE in practical assessment.

Synthesis and characterization of cerium, silver and copper oxide nanoparticles and their anticancer potential of hepatocellular carcinoma HepG2 cancer cells

The current work employs the traditional chemical (precipitation) approach for synthesis, characterization and application of silver (AgO2), cerium (CeO2), and copper (CuO2) nanoparticles (NPs) against hepatocellular carcinoma. Nanoparticles were prepared and characterized by advance instrumental techniques including scanning electron microscope-energy dispersive spectroscopy (SEM-EDS), energy dispersive X-ray (EDX) and elemental mapping, X-Ray diffraction (XRD), Fourier transmission infrared (FTIR), ultraviolet visible (UV-Vis) spectroscopy. The cytotoxicity of fabricated NPs was tested on human liver cancer line (HepG2). Initial confirmation of NPs was done using UV-Visible spectroscopy. The distinct (2q) peak associated with various forms was verified by XRD data. SEM-EDS and EDX were used to verify the existence of the synthesized NPs. In a secondary electron (SE) SEM image, particles were clustered in a less porous form via a clustered shape. Three NPs were identified to have an average size less than 56 nm. The standard parameters of all three nanoparticles matched perfectly according to FTIR analysis. Chemically-synthesized silver, cerium and copper NPs have 53%, 44%, and 46% inhibition response at 100 µg/ml concentration against HepG2 cells. Current study demonstrated dose dependent effect of chemically synthesized NPs against hepatic cancer cell line with maximum inhibition at higher concentration (100 µg/ml).

Photocatalytic Performance of Sn–Doped TiO2 Nanopowders for Photocatalytic Degradation of Methyl Orange Dye

The tin-doped TiO2 powders obtained by sol-gel and microwave-assisted sol-gel methods were investigated. The synthesis took place in a basic medium (pH 10, ammonium hydroxide, 25%) starting from tetrabutyl orthotitanate in its parental alcohol. In the case of the dopant, Tin(II) 2-ethylhexanoate as SnO2 precursor was used in the amount of 1, 2, or 4 mol % SnO2. Based on thermal analysis data, the powders were thermally treated in air, at 500 °C. The comparative investigation of the structure and morphology of the nanopowders annealed at 500 °C was performed by scanning electron microscopy (SEM), high-resolution transmission electron microscopy with selected area electron diffraction (HRTEM/SAED), scanning transmission electron microscopy (STEM) coupled with EDX mapping, Fourier transmission infrared (FTIR), UV–Vis, Raman and photoluminescence (PL) spectroscopy, X-ray diffraction (XRD), and X-ray florescence spectroscopy (XRF). The obtained materials were tested for the photocatalytic removal of methyl orange dye from aqueous solutions. High degradation efficiencies (around 90%) were obtained by Sn doping after 3 h of UV light irradiation.

Fabrication and characterisation of poly(vinyl alcohol)/chitosan scaffolds for tissue engineering applications

In this study, poly(vinyl alcohol)/chitosan (PVA/CS) scaffolds were fabricated by freeze-drying method and the characterisations of obtained scaffolds were carried out to analyse the suitability of the product for biomedical applications such as tissue engineering. The effect of initial PVA concentrations and their hydrolysis degrees, the addition of different molecular weights (MWs) of CS along with the blending ratio of PVA/CS were studied. Fourier transmission infrared (FTIR) spectroscopy showed the presence of chemical bonds in PVA and PAV/CS scaffolds and the energy dispersive X-ray (EDX) spectroscopy confirmed the existence of the chemical element nitrogen in PVA/CS scaffolds. The stability of scaffolds under physiological conditions was studied by swelling and degradation tests, which demonstrated the effect of initial PVA concentration and CS addition on the water resistance of scaffolds. Scanning Electron Microscopy (SEM) images showed highly porous structures which became more uniform in pore size with the addition of CS. The mechanical properties of dry and hydrated scaffolds were also investigated by an unconfined compression test and the compressive modulus and maximum stress at 20% strain were calculated through stress–strain curves. The in-depth characterisation of scaffolds showed that the initial concentration and blending ratio of PVA/CS can be adjusted to tailor the desired properties of scaffolds for different biomedical applications.

EFFECT OF ACID HYDROLYSES ON PROPERTIES OF CELLULOSE/POLY FURFURAL ALCOHOL (PFA) COMPOSITES FROM MAIZE STALK

The study investigated morphology and thermal properties of cellulose/poly furfural alcohol (PFA) composites prepared from maize stalk through acid mixtures. The cellulose nanocrystals (CNCs) were extracted from maize stalk via acid hydrolysis using mixtures of various acids.The prepared CNCs were encapsulated in a PFA matrix via in situpolymerization process using p-toluene sulfonic acid as catalyst. The properties of untreated maize stalk, cellulose and their nanocomposites were analysed by scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transmission infrared (FTIR) and thermogravimetric analysis (TGA). The crystallinity of maize stalk was generally increased after an acid hydrolysis dominated by H2SO4/HNO3 and H2SO4/HCl. The same trend was observed from TGA, except that H2SO4/H3PO4and H2SO4/HClO4dominated thermal stability trailed by H2SO4hydrolysed CNC nanocomposite. The surface breakage of fibers observed in SEM images was depended on the strength of acids used tohydrolysed the CNC. There was also evidence of aggregation and cracked PFA surface with addition of acid hydrolysed CNCs, dependent on the acids strength. The H2SO4/HClO4hydrolysed CNC/PFA displayed afairly good dispersion of CNCs in the PFA matrix with no surface breakage.

Eco-Friendly Chitosan-Based Biodiesel Heterogeneous Catalyst Support Membrane

A chitosan-polyvinyl pyrrolidone K-30 (Cs-PVP.K30) membrane was prepared as a heterogeneous catalyst supporting membrane in the transesterification process in the production of biodiesel from palm oil and methanol through the blend reaction between chitosan (Cs) and polyvinyl pyrrolidone K-30 polymer (PVP K-30). Several membranes were characterized by their physicochemical and catalytic properties. Based on physicochemical data, it was found that including the carbonyl group from PVP K-30 into the chitosan framework correlated with an increase in porosity, hydrophilicity, water absorption, and the degree of swelling of the membrane. The results of the analysis using Fourier Transmittance Infra-red (FTIR) showed the spectra of carbonyl (-C=O) and hydroxyl (-OH) groups at wavenumbers 1648 cm-1 and 3363 cm-1, which shows that the reaction of chitosan alloy with PVP K-30 has been successfully carried out. The catalytic site of the Cs-PVP K30-NaOH membrane in the biodiesel production process was studied under several conversion conditions. It was found that the conversion of biodiesel reached 93.90% with a reaction time of 90 minutes, a temperature of 65°C, and an oil/methanol mole ratio of 1:7.

Green Synthesis of Blue-Emitting Graphene Oxide Quantum Dots for In Vitro CT26 and In Vivo Zebrafish Nano-Imaging as Diagnostic Probes.

Graphene oxide quantum dots (GOQDs) are prepared using black carbon as a feedstock and H2O2 as a green oxidizing agent in a straightforward and environmentally friendly manner. The process adopted microwave energy and only took two minutes. The GOQDs are 20 nm in size and have stable blue fluorescence at 440 nm. The chemical characteristics and QD morphology were confirmed by thorough analysis using scanning electron microscope (SEM), transmission electron microscope (TEM), atomic force microscope (AFM), Fourier transmission infra-red (FT-IR), and X-ray photoelectron spectroscopy (XPS). The biocompatibility test was used to evaluate the toxicity of GOQDs in CT26 cells in vitro and the IC50 was found to be 200 µg/mL with excellent survival rates. Additional in vivo toxicity assessment in the developing zebrafish (Danio rerio) embryo model found no observed abnormalities even at a high concentration of 400 μg/mL after 96 h post fertilization. The GOQDs luminescence was also tested both in vitro and in vivo. They showed excellent internal distribution in the cytoplasm, cell nucleus, and throughout the zebrafish body. As a result, the prepared GOQDs are expected to be simple and inexpensive materials for nano-imaging and diagnostic probes in nanomedicine.

Characterization and Biological Studies of Synthesized Titanium Dioxide Nanoparticles from Leaf Extract of Juniperus phoenicea (L.) Growing in Taif Region, Saudi Arabia

Green synthesis of metal nanoparticles in nanosized form has acquired great interest in the area of nanomedicine as an environmentally friendly and cost-effective alternative compared to other chemical and physical methods. This study deals with the eco-friendly green synthesis of titanium dioxide nanoparticles (TiO2 NPs) utilizing Juniperus phoenicea leaf extract and their characterization. The biosynthesis of TiO2 NPs was completed in 3 h and confirmed by UV-Vis spectroscopy, a strong band at 205.4 nm distinctly revealed the formation of NPs. Transmissions electron microscopy (TEM) analysis showed the synthesized TiO2 NPs are spherical in shape, with a diameter in a range of 10–30 nm. The XRD major peak at 27.1° congruent with the (110) lattice plane of tetragonal rutile TiO2 phase. Dynamic light scattering (DLS) analysis revealed synthesized TiO2 NPs average particle size (hydrodynamic diameter) of (74.8 ± 0.649) nm. Fourier transmission infrared (FTIR) revealed the bioactive components present in the leaf extract, which act as reducing and capping agents. The antimicrobial efficacy of synthesized TiO2NPs against, Staphylococcus aureus, and Bacillus subtilis (Gram-positive), Escherichia coli and Klebsiella pneumoniae (Gram-negative), Yeast strain (Saccharomyces cerevisiae) and fungi (Aspergillus niger, and Penicillium digitatum) assayed by a disc diffusion method. TiO2NPs inhibited all tested strains by mean inhibition zone (MIZ), which ranged from the lowest 15.7 ± 0.45 mm against K. pneumoniae to the highest 30.3 ± 0.25 against Aspergillus niger. The lowest minimum inhibitory concentration (MIC) and bactericidal (MBC) values were 20 μL/mL and 40 μL/mL of TiO2NPs were observed against Asp. niger. Moreover, it showed significant inhibitory activity against human ovarian adenocarcinoma cells with IC50 = 50.13 ± 1.65 µg/mL. The findings concluded that biosynthesized TiO2 NPs using Juniperus phoenicea leaf extract can be used in medicine as curative agents according to their in vitro antibacterial, antifungal, and cytotoxic activities.

Pharmaceutical Co-crystal of Antiviral Agent Efavirenz with Nicotinamide for the Enhancement of Solubility, Physicochemical Stability, and Oral Bioavailability.

The present research work attempted to improve the oral bioavailability of the antiviral drug Efavirenz (EFV) using a pharmaceutical cocrystallization technique. EFV comes under BCS-II and has extremely low water solubility, and results in low oral bioavailability. EFV and nicotinamide (NICO) were selected in a (1:1) stoichiometric ratio and efavirenz nicotinamide cocrystal (ENCOC) was prepared through the liquid-assisted grinding method (LAG). The confirmation of the formation of a new solid phase was done through spectroscopic techniques like Fourier transmission infrared (FTIR), Raman, and 13C solid-state nuclear magnetic resonance (13C ssNMR). Thermal techniques like differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and hot stage microscopy (HSM) illustrated the thermal behavior and melting patterns of ENCOC, EFV, and NICO. The X-ray powder diffraction (XRPD) confirms the formation of a new crystalline phase in ENCOC. The Morphology was determined through scanning electron microscopy (FESEM). The results of saturated solubility studies andin vitro drug release studies exhibited 8.9-fold enhancement in solubility and 2.56-fold enhancement in percentage cumulative drug release. The percentage drug content of ENCOC was found higher than 97% and cocrystal exhibits excellent accelerated stability. The oral bioavailability of EFV (Cmax, 799.08ng/mL) exhibits significant enhancement after cocrystallization (Cmax, 5597.09ng/mL) than EFV and Efcure®-200 tablet (2896.21ng/mL). The current work investigates the scalable and cost-effective method for enhancement of physicochemical stability, solubility, and oral bioavailability of an antiviral agent EFV.

Appraisal of hydrochemistry and suitability assessment for water in an agriculture-dominated aquatic ecosystem of Rajasthan, India

The study is the first comprehensive investigation of the water quality and geochemistry of an ecologically important large endorheic lake located in Rajasthan, India. The water quality and its suitability appraisal classified the water as fit for drinking, irrigation, and industrial application with the possible problem of corrosion. Most of the dissolved ions were observed to be coming from crustal/natural origin, with the exception of chloride. The water was observed to be MgHCO3 type and CaMgCl type based on the relative abundance of ions. Considering the environmental relevance towards eutrophication, the Nitrogen:Phosphorous (N:P) value of 10:1 in water classified the lake in transition from oligotrophic to eutrophic with an urgent need of intervention to arrest addition of domestic wastewater and agricultural runoff. Additionally, Fourier Transmission Infra-Red (FTIR) investigation of sediments and soil revealed that the chemical signatures of soil and sediments are similar, and most of the sediments are transported into the lake from a short distance. The geochemical classification of water and mineralogical profile of soil and sediments of the lake confirmed that rock–water interaction (silicate weathering in particular) is controlling the water chemistry via direct cation exchange. Considering the importance of lake as a hotspot for tourists, migratory birds, crocodile conservation, aquaculture and its application for irrigation and drinking, present study recommends effective management of water quality for its sustainable use.Graphical abstract