UV-Vis Spectrophotometer Analysis Research Articles

Photo-catalytic dye degradation potentials of Ag-Pd bimetallic nanoparticles synthesized from Vitex negundo.

Plant extracts are a great alternative to synthesizing nanoparticles of different metals and metal oxides. This green synthesis method has opened up numerous possibilities in various scientific domains. In present study, Leaf extract from Vitex negundo is a non-deciduous, long-lasting shrub from the Verbenaceae family is used as capping and reducing agents for the synthesis of silver and palladium nanoparticles. The characterization study UV-vis spectrophotometer analysis showed absorbance value around 320nm which confirming that Ag-Pd nanoparticles have been successfully obtained. Further, SEM is used to investigate the morphology of Ag-Pd NPs, which revealing their spherical and rod-like configuration, aggregation, and the size of the particles are obtained between 50 and 100nm. The successful synthesis of Ag-Pd NPs was further confirmed by the EDAX chart, which displayed the peak of Ag and Pd at bending energies between 0.5 and 1.5keV. According to the quantitative study, Ag and Pd ions found about 5.24 and 13.28%, respectively. In addition, surface studies with TEM confirming that synthesized Ag-Pd NPs are predominates with spheres structure morphologies, with sizes averaging 11.20nm and ranging from 10 to 20nm. Further, Ag-Pd nanoparticles was applied as potential photocatalyst materials to degrade methylene blue dye and found about 85% of the degradation efficiency within 150min of the sunlight exposure thus could be used as catalyst to removal of hazardous organic dye molecules.

A captivating approach to elevate the detection of Al3+ ions incorporates the utilization of a tripodal receptor intricately embellishing the surface of zinc oxide

The FDA (Food and Drug Administration, (USA)) lists ZnO as a material that is widely acknowledged to be safe. ZnO NPs with a range of tiny particle sizes were made using the precipitation process. ZnO nanoparticles' surface is embellished with a tripodal sensor containing naphthol units. The assembly with the same receptor decorated on ZnO NPs is contrasted with the cation detection capabilities of the purified tripodal receptor. The UV–visible spectrophotometric analysis was conducted to study the state transitions of the receptor and the decorated ZnO receptor. A positive selectivity to Al3+ cations is determined by the fluorescence study under ideal circumstances. The particle size and surface morphologies are determined by DLS and SEM analysis for the same receptor − TP1 and embellished with a tripodal receptor TP2. Using a fluorescence switch-on Photoinduced Electron Transfer (PET) mechanism, the receptor coated on ZnO detects the presence of Al3+ ions with specificity. The binding constant value was determined using the B-H plot equation. Binding stoichiometry for [TP1-Al3+, TP2-Al3+] showed a 1:1 ratio. The fluorescence switches ON-OFF process of the ZnO surface adorned − TP2 with Tripodal receptor- TP1 was used to create molecular logic gates, which can function as a module for sensors and molecular switches. The addition of Na2EDTA in the solution of the [TP1; TP2 − Al3+] complex resulted in a noticeable reduction in the emission of fluorescence. This finding offers compelling support for the reversibility of the chemosensor. To enable the practical application of this sensor, we have developed a cassette containing receptors TP1 and TP2. Successfully, it can detect Al3+ metal ions. We performed a comprehensive assessment of the dependability and appropriateness of our approach in measuring the concentration of Al3+ ions in wastewater produced by important industrial procedures.

Green Synthesis of Molybdenum Nanoparticles From Solanum xanthocarpum and Evaluation of Their Antimicrobial and Antioxidant Activity Against Multidrug-Resistant Wound Isolates.

In recent years, antimicrobial drug resistance has emerged as a serious global public health concern, according to the World Health Organization data. The emergence of pathogens resistant to multiple drugs has been linked to an increase in morbidity and mortality from microbial infections. The study's main goal is to explore the efficacy of using Solanum xanthocarpum in the green synthesisof molybdenum nanoparticles (Mo NPs) for antibacterial and antioxidant properties. An eco-friendly method of synthesizing Mo NPswas accomplished using an aqueous extract of Solanum xanthocarpum. Characterization of the synthesized nanoparticles was done by UV-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FT-IR),X-ray diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX). After that,antibacterial and antioxidant activity was further evaluated. The UV-visible spectrophotometer analysis confirmed the presence of synthesized Mo NPs showing a peak around 320 nm. The presence of functional compounds like C-CI, C-H, C=C, and O=C=O was confirmed by FT-IR spectrum analysis. The positions of diffraction peaks in Mo NPpatterns were identified using XRD analysis; they were more crystalline (82.7%) and less amorphous (17.3%). The presence of the elements molybdenum (Mo), carbon (C), and oxygen (O) was confirmed by the EDX spectrum and irregular shapesshown in the SEM images. Further, the antimicrobial study results showed the formation of an inhibition zone against 27 mm for Klebsiella pneumoniae, 24 mm for Pseudomonas aeruginosa, 22 mm for Staphylococcus aureus, and 24 mm for Enterococcus faecalis,respectively, at a high concentration 80 μg/ml of Mo NPs. The maximum antioxidant activity at 100 μg/ml was 73.49%, compared to the standard ascorbic acid (74.25%). Additionally, the moderate activity at 60 μg/ml was 53.21%, compared to the standard (56.5%), and the minimal activity at 20 μg/ml was 30.21%, compared to the standard (36.89%). The environmentally friendly synthesizedMo NPsfrom Solanum xanthocarpum exhibited antioxidant activity. Furthermore, the findings showthat Mo NPs mediated by Solanum xanthocarpum can inhibit antibiotic-resistant bacteria, especially methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, andEnterococcus faecalis. In order to understand furtherhow nanoparticles work against bacteria that are resistant to many drugs,additional research and clinical studies would be needed.

Investigation of different solvents for selective, safe and rapid extraction of curcumin from various food and herbal supplement products: Multivariate strategy and assessment of green profile

In the paper, different extraction solvents including magnetic ionic liquids (MILs), deep eutectic solvents, SUPRAS and surfactant were investigated for the fast, reliable and simple extraction of curcumin in the dispersive liquid–liquid microextraction (DLLME) method prior to UV–Vis spectrophotometric analysis. As a result of preliminary studies, the [Co(C8IM)42+]2[Cl−] MIL was selected as the extraction solvent for the extraction of curcumin from various matrix samples. Optimization of essential factors in the DLLME method was carried out with central composite design (CCD). Effective dispersion of the [Co(C8IM)42+]2[Cl−] MIL in the sample solution was achieved by orbital shaking (OS). After the CCD modelling, the OS-MIL-DLLME method provided linearity in the range of 0.5–225 ng mL−1 with a detection limit of 0.15 ng mL−1 for the model solution. The OS-MIL-DLLME method showed a matrix effect of 7.6 % with an enrichment factor of 135. Validation parameters of the OS-MIL-DLLME method such as selectivity, robustness, intraday/interday precision and recovery test were investigated in detail. The green analytical scale of the method was determined using the analytical greenness calculator tool. The OS-MIL-DLLME method was applied to the foods and herbal supplement products together with the reference method, and quantitative recoveries and statistically reliable results were obtained.

Exploring sustainable management by using green nano-silver to combat three post-harvest pathogenic fungi in crops

Global crop protection and food security have become critical issues to achieve the ‘Zero Hunger’ goal in recent years, as significant crop damage is primarily caused by biotic factors. Applying nanoparticles in agriculture could enhance crop yield. Nano-silver, or AgNPs, have colossal importance in many fields like biomedical, agriculture, and the environment due to their antimicrobial potential. In this context, nano-silver was fabricated by Citrus medica L. (Cm) fruit juice, detected visually and by UV–Vis spectrophotometric analysis. Further, AgNPs were characterized by advanced techniques. UV–Vis spectroscopic analysis revealed absorbance spectra at around 487 nm. The zeta potential measurement value was noted as -23.7 mV. Spectral analysis by FT-IR proved the capping of the acidic groups. In contrast, the XRD analysis showed the Miller indices like the face-centered cubic (fcc) crystalline structure. NTA revealed a mean size of 35 nm for nano-silver with a 2.4 × 108 particles mL−1 concentration. TEM analysis demonstrated spherical Cm-AgNPs with 20–30 nm sizes. The focus of this research was to evaluate the antifungal activity of biogenic AgNPs against post-harvest pathogenic fungi, including Aspergillus niger, A. flavus, and Alternaria alternata. The Cm-AgNPs showed significant antifungal activity in the order of A. niger > A. flavus > A. alternata. The biogenic Cm-AgNPs can be used for the inhibition of toxigenic fungi.

In situ NADES microwave‐mediated extraction of bioactive compounds from Beta vulgaris L. var. rubra waste

SummaryThe research focused on the recovery of bioactive compounds from beetroot waste (fresh stalks) using an innovative and microwave‐mediated (mw) procedure that could allow the simultaneous eutectic solvent preparation and matrix extraction (in situ mw NADES extraction), as a simplification of more conventional NADES (natural deep eutectic solvents) extractions. The main goal was to propose a fast and simple “one‐pot” extractive approach to obtain and screen non‐toxic, bioactive ready‐to‐use ingredients, potentially useful in food, cosmetic and pharmaceutical fields, meanwhile converting beetroot residues, from worn‐out plant matrices to recycled sources with significant added values. With this purpose, several eutectic mixtures of natural food‐grade hydrogen bond donors (choline chloride or betaine) and hydrogen bond acceptors (fructose, urea, citric acid, and glycerol) were selected and investigated (in opportune ratios) under microwave activation, considering time, temperature, and solvent‐to‐matrix ratio as the influencing variables and the total phenols content recovery as the response. By the in situ NADES microwave method developed, the best results were obtained within 5 min at 70 °C with recoveries of around 0.5 mg of polyphenols for gram of fresh stalks, assessed by the Folin–Ciocalteu test. The suitability of the NADES‐based extractives, as radical scavenging agents, was evaluated using the DPPH assay, which highlighted their good antioxidant activity; moreover, monitoring the betacyanin content by means of UV–vis spectrophotometric analyses, it was evident that NADES provide a relevant stability to the new complexes (up to 3 months) compared to water (24 h). The new in situ process proposed could be also useful for preliminary screenings of different organic matrices, simplifying workup, streamlining the procedures, and reducing costs.

Adsorption of Methylene Blue using the Biosorbent of Coconut Fiber Activated by Nitric Acid

The textile industry in the world keeps increasing, but it harms environmental pollution caused by textile dye waste. Synthetic dyes contain carcinogenic and mutagenic ingredients that can demage the environment and aquatic biota. The alternative to handling dye pollution with a low-cost method is adsorption using nitric acid-activated coconut fiber. Coconut fiber was an abundant agricultural waste and economical, and it had an active site that contained many compounds such as cellulose, lignin, pyroligneous acid, and tannin molecules. This study used the UV-Vis Spectrophotometer analysis method to determine the effect of pH, contact time, and coconut fiber on the adsorption capacity of methylene blue. The result showed that the optimal conditions for adsorption were a pH of 5, a contact time of 75 minutes, and a percentage adsorption of the variation of contact time of 99.628%. The adsorption study was according to a pseudo-second-order reaction with a constant reaction rate of 0.050 g mg-1 minute-1. The maximum adsorption capacity was 2 mg g-1, with the percentage of methylene blue adsorbed at 99.84%. Adsorption occurs chemically with an energy of 35.4 kJ mol-1, so it can be determined that it occurs with a monolayer mechanism.
  
 Keywords: Adsorption, biosorbent, isothermal, kinetic, methylene blue

The effects of biosynthesized silver nanoparticle on oxidative stress parameters in model organism Artemia salina (Linnaeus, 1758)

Evaluation of the effects of nanomaterials in various habitats and living groups is increasing with in vitro and in vivo studies. This study aims to describe a biological procedure to synthesize silver nanoparticles using an extract of Marrubium astracanicum and to determine the aquatic environment’s oxidative stress on Artemia salina. Silver nanoparticle formation was visually observed with color change. Its structural properties, such as size, shape, morphology, and stability, were characterized by UV-Vis spectrophotometer, TEM, SEM, XRD, and DLS analyses. TEM image showed that the synthesized AgNPs have a size of between 20 and 50 nm. The effects of biosynthesized silver nanoparticles at different concentrations (control,0.2, 1, 5, 10, 25, and 50 mg/mL) and exposure times (24, 48 and 72 h) on total glutathione (GSH) and lipid peroxidation levels (MDA) were investigated on the Artemia salina organism, which is one of the most common saltwater organisms frequently used in ecotoxicity tests.

Synergistic Effect of Nilavembu Choornam-Gold Nanoparticles on Antibiotic-Resistant Bacterial Susceptibility and Contact Lens Contamination-Associated Infectious Pathogenicity.

Antibiotic-resistant bacterial colonies mitigate rapid biofilm formation and have complex cell wall fabrications, making it challenging to penetrate drugs across their biofilm barriers. The objective of this study was to investigate the antibacterial susceptibility of antibiotic-resistant bacteria and contact lens barrenness. Nilavembu Choornam-Gold Nanoparticles (NC-GNPs) were synthesized using NC polyherbal extract and characterized by UV-visible spectrophotometer, SEM-EDX, XRD, Zeta sizer, FTIR, and TEM analysis. Contact lenses with overnight cultures of antibiotic-resistant bacteria K. pneumoniae and S. aureus showed significant differences in growth, biofilm formation, and infection pathogenicity. The NC-GNPs were observed in terms of size (average size is 57.6 nm) and surface chemistry. A zone of inhibition was calculated for K. pneumoniae 18.8 ± 1.06, S. aureus 23.6 ± 1.15, P. aeruginosa 24.16 ± 0.87, and E. faecalis 24.5 ± 1.54 mm at 24 h of NC-GNPs alone treatment. In electron microscopy studies, NC-GNP-treated groups showed nuclear shrinkage, nuclear disintegration, degeneration of cell walls, and inhibited chromosomal division. In contrast, normal bacterial colonies had a higher number of cell divisions and routinely migrated toward cell multiplications. NC-GNPs exhibited antibacterial efficacy against antibiotic-resistant bacteria when compared to NC extract alone. We suggest that NC-GNPs are highly valuable to the population of hospitalized patients and other people to reduce the primary complications of contact lens contamination-oriented microbial infection and the therapeutic efficiency of antibiotic-resistant bacterial pathogenicity.

Iron oxide (Fe3O4) and ciprofloxacin loaded magnetic nanoparticles for magnetic drug targeting

Iron oxide (Fe3O4) pristine and ciprofloxacin loaded nanoparticles are synthesized successfully using co-precipitation method. X-ray diffraction analysis confirms the pure phase formation of the synthesized Fe3O4 particles. The grain size of the Fe3O4 calculated from the SEM images comes out to be 50 nm. UV-VIS spectrophotometric analysis indicates the accuracy of the results in which an absorption maximum of blank and ciprofloxacin containing iron oxide (Fe3O4) particle was observed at 260 and 265 nm respectively. The spectrum band shows the maximum absorption band shift of around 4-5 nm which may be explained by the drug conjugation to the Fe3O4 nanoparticles. The spectrum indicates the formation of Fe3O4 magnetic nanoparticles having black color and obtained material is found with energy band gap (E) of 2.12 eV and 2.19 eV. On the basis of the findings from dynamic light scattering (DLS) results, it can be concluded that overall particle size of magnetic iron oxide nanoparticles is observed as 765 nm. In the present study the polydispersity index (P.I.) of bare Fe3O4 magnetic nanoparticles is 0.221, which indicate the hydrodynamic property of the synthesized particles.

Influence of Water Concentration on High-Temperature Reactive Condensation of Chromium Vapors Generated in 800 °C Air

Reactive evaporation of chromium (Cr) from stainless steels used in solid oxide electrochemical systems, such as solid oxide fuel cell (SOFC) and solid oxide electrolysis cell (SOEC) systems, is well-documented. However, the condensation and interactions of volatilized Cr species onto and with surrounding interfaces during complex and dynamic system exposures is less understood. Understanding these interactions during operation is critical for improving system performance and safeguarding environmental, health and safety, as some condensed species contain toxic hexavalent Cr (Cr(VI)). The objective of this study is to investigate the condensation pathways of Cr vapors within representative high-temperature system environments. To accomplish this objective, Cr vapors, produced by high-temperature (800 °C) air exposures of trivalent chromium (Cr(III)) oxide (Cr2O3) powder with variable moisture content, were condensed onto various ceramic materials at lower temperatures (<400 °C). The total amount of Cr and ratios of oxidation states were measured using inductively coupled plasma optical emission spectroscopy (ICP-OES) and diphenyl carbazide (DPC) colorimetric/direct UV–vis spectrophotometer analyses. Increased Cr condensation was observed with increased water content, with similar Cr(VI) to total Cr ratios. Results and interpretations are discussed in context of improving understanding of Cr reactive condensation in SOFC/SOEC and related high-temperature materials and systems.

Synergistic antibacterial and mosquitocidal effect of Passiflora foetida synthesized silver nanoparticles.

Silver nanoparticles are opted to have various applications in different fields ranging from traditional medicines to culinary items. It is toxic and most effective against bacteria, fungi viruses, parasites, parasite carrying vectors such as mosquitoes and their larvae and other eukaryotic microorganisms at low concentration without any side effects and toxicity to humans. In view of these data, the present research has been investigated by synthesizing silver nanoparticles using 1mM silver nitrate and aqueous extract of Passiflora foetida. The variation of nanoparticles in size and shape concerning the concentration of extract prepared were analysed. The formation of silver nanoparticles was confirmed by colour changing from yellowish green to reddish-brown implicating the surface plasmon resonance. Further, it was concluded by obtaining an absorbance peak at 420 nm using UV-Visible spectrophotometer analysis. FTIR analysis was used to identify the capping ligands, which included alkanes, aromatic groups and nitro compounds. The average grain size of ~12 nm to 14 nm with crystalline phase was revealed by X-ray Diffraction studies. The SEM images depicted the surface morphology with agglomeration; TEM studies showed the shape of nanoparticles as spherical and hexagonal with sizes ranging from 40 nm to 100 nm and EDAX analysis confirmed the presence of elemental silver as the principal constituent. The characterized silver nanoparticles were then tested for synergistic antibacterial effects with tetracycline, and the results show that they are more active against E. coli and S. aureus, but moderately effective against B. cereus and K. pneumoniae . It also had a strong larval and pupal toxic effects on the dengue vector, Aedes aegypti with the highest mortality. As a result, silver nanoparticles could be a viable alternative for a variety of applications.

Green and efficient magnetic micro-solid phase extraction utilizing tea waste impregnated with magnetic nanoparticles for the analysis of ibuprofen in water samples by using UV-vis spectrophotometry.

A green method based on magnetic micro-solid phase extraction (MNP-TW-μ-SPE) of tea waste impregnated with magnetic nanoparticles (MNP-TW) was developed for the extraction of ibuprofen (IBP) in water samples prior to UV-Vis spectrophotometric analysis. Experimenting parameters that affect the extraction efficiency of IBP, such as pH of the sample solution, sorbent dosage, extraction time, ionic strength, volume of the sample, type of desorption solvent, desorption time, and desorption volume, were studied and optimized in detail. The characterization studies for the MNP-TW were carried out by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectrometry (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) analysis, a vibrating sample magnetometer (VSM), and thermogravimetric analysis (TGA). Under the optimum conditions, the linearity ranges from 30 to 700 μg L-1 for IBP, with determination coefficients (R2) of 0.9983. The limit of detection (LOD) and limit of quantification (LOQ) were 9.40 μg L-1 and 28.50 μg L-1, respectively. The method also demonstrated good precision in reproducibility (RSD ≤ 1.53%), repeatability (RSD ≤ 1.48%), and recovery (86-115%). This method represents the advantages of low solvent consumption, flexibility, and better sensitivity compared to other studies employing spectrophotometric analysis. The usage of tea waste in the extraction process presents many advantages, as it is biodegradable, versatile, and contributes to an intelligent and sustainable economic strategy projected toward a circular economy approach.

Eco-Friendly Silver Nanoparticles Synthesized from a Soybean By-Product with Nematicidal Efficacy against Pratylenchus brachyurus.

This study explores an eco-friendly approach to synthesizing silver nanoparticles (AgNPs) using soybean leaf extracts, employing a reaction with silver nitrate at 65 °C for 2.5 h. Optimal results were achieved at extract concentrations of 3.12 and 6.25 mg of the leaf mL-1, termed 3.12AgNP and 6.25AgNP, respectively. UV-Vis spectrophotometric analysis between 350 and 550 nm exhibited a peak at 410-430 nm, along with a color transition in the suspensions from pale yellow to brown, indicating successful synthesis. Dynamic light scattering (DLS) further delineated the favorable properties of these AgNPs, including nanometric dimensions (73-104 nm), negative charge, and moderate polydispersity, portraying stable and reproducible synthesis reactions. The bioreduction mechanism, possibly expedited by leaf extract constituents such as amino acids, phenolic acids, and polysaccharides, remains to be fully elucidated. Notably, this study underscored the potent nematicidal effectiveness of biosynthesized AgNPs, especially 6.25AgNP, against Pratylenchus brachyurus, which is a common plant-parasitic nematode in tropical soybean cultivation regions. In vitro tests illustrated significant nematicidal activity at concentrations above 25 µmol L-1, while in vivo experiments displayed a pronounced nematode population diminishment in plant roots, particularly with a 6.25AgNP rhizosphere application at concentrations of 500 µmol L-1 or twice at 250 µmol L-1, attaining a reproduction factor below 1 without any morphological nematode alterations. This research highlights the potential of 6.25AgNPs derived from soybean leaf extracts in forging sustainable nematicidal solutions, marking a significant stride toward eco-friendly phytonematode management in soybean cultivation. This novel methodology signals a promising avenue in harnessing botanical resources for nematode control and propelling a greener agricultural horizon.

Pengaruh Variasi Prekursor Terhadap Morfologi dan Aktivitas Antibakteri Nanopartikel Tembaga Menggunakan Reduktor Ekstrak Daun Gambir

Research on synthesis copper nanoparticles has been carried out by the bioreduction method with a green synthesis approach using extracts of gambir leaves (Uncaria gambir Roxb). Gambir leaf extract contains polyphenol compounds uses as a natural reducing agent to reduce copper cation from variations of prekursor (CuSO45.H2O, Cu(NO3)2.3H2O and CuCl2.2H2O). The formation of copper nanoparticles (CuNP) colloid is visually shown by color change from light brown to dark brown. Absorption peak in UV-Vis spectrophotometer analysis at 405 -427 nm which is a specific wavelength of copper nanoparticles base on phenomenon of Surface Plasmon Resonance (SPR). The X-Ray Diffraction (XRD) analysis showed formation of CuNP with a face centered cubic (fcc) crystal structure. The result of Transmission Electron Microscope show the synthesized CuNP was spherical with particle size diameter 15nm for CuSO4 prekursor, 25 nm for Cu(NO3) prekursor and  28 nm for CuCl2 prekursor. The size of nanoparticles influenced of type prekursor anions. The antibacterial activity of the synthesized nanoparticles was also tested using pathogenic bacteria Escherichia coli and Staphylococcus aureus. The results showed that copper nanoparticles were promising antibacterial agents. Antibacterial activity test on copper nanoparticles were found to have higher antibacterial activity against Gram positive bacteria S. aureus than Gram negatif E. coli.

Selective Separation of Americium(III), Curium(III), and Lanthanide(III) by Aqueous and Organic Competitive Extraction.

Adding hydrophilic ligands into aqueous solutions for the selective binding of actinides(III) is acknowledged as an advanced strategy in Ln(III)/An(III) separation. In view of the recycling and radioactive waste disposal of the minor actinide, there remains an urgent need to design and develop the appropriate ligand for selective separation of An(III) from Ln(III). Herein, four novel hydrophilic ligands with hard-soft hybrid donors, derived from the pyridine and phenanthroline skeletons, were designed and synthesized as masking agents for selective complexation of An(III) in the aqueous phase. The known N,N,N',N'-tetraoctyl diglycolamide (TODGA) was used as lipophilic extractant in the organic phase for extraction of Ln(III), and a new strategy for the competitive extraction of An(III) and Ln(III) was developed based on TODGA and the above hydrophilic ligands. The optimal hydrophilic ligand of N,N'-bis(2-hydroxyethyl)-2,9-dicarboxamide-1,10-phenanthroline (2OH-DAPhen) displayed exceptional selectivity toward Am(III) over Ln(III), with the concentrations of HNO3 ranging from 0.05 to 3.0 M. The maximum separation factors were up to 1365 for Eu/Am, 417.66 for Eu/Cm, and 42.38 for La/Am. The coordination mode and bonding property of 2OH-DAPhen with Ln(III) were investigated by 1H NMR titration, UV-vis spectrophotometric titration, luminescence titration, FT-IR, ESI-HRMS analysis, and DFT calculations. The results revealed that the predominant species formed in the aqueous phase was a 1:1 ligand/metal complex. DFT calculations also confirmed that the affinity of 2OH-DAPhen for Am(III) was better than that for Eu(III). The present work using a competitive extraction strategy developed a feasible alternative method for the selective separation of trivalent actinides from lanthanides.

Synthesis, structure elucidation, SC-XRD/DFT, molecular modelling simulations and DNA binding studies of 3,5-diphenyl-4,5-dihydro-1H-pyrazole chalcones

Deoxyribonucleic acid (DNA) acts as the most important intracellular target for various drugs. Exploring the DNA binding interactions of small bioactive molecules offers a structural guideline for designing new drugs with higher clinical efficacy and enhanced selectivity. This study presents the facile synthesis of pyrazoline-derived compounds (4a)-(4f) by reacting substituted chalcones with hydrazine hydrate using formic acid. The structure elucidation of substituted pyrazoline compounds was carried out using 1H-NMR, FT-IR and elemental analyses. While the crystal structures of two compounds (4a) and (4b) have been resolved by single-crystal X-ray diffraction (SC-XRD) analysis. Hirshfeld surface analysis also endorsed their greater molecular stability. Computational calculations at DFT/B3LYP/6-311++G(d,p) were executed to compare the structural properties (bond angle and bond length) and explore reactivity descriptors, frontier molecular orbitals (FMO), Mulliken atomic charges (MAC), molecular electrostatic potential (MEP) and electronic properties. All the compounds were evaluated for DNA binding interactions by UV-Vis spectrophotometric analysis. The results revealed that compounds (4a)-(4f) bind to DNA via non-covalent binding mode having binding constant values ranging from 1.22 × 103 to 6.81 × 104 M−1. The negative values of Gibbs free energy also proved the interaction of studied compounds with DNA as a spontaneous process. The findings of molecular docking simulations depicted that these studied compounds showed significant binding interactions with DNA and these results were consistent with experimental findings. Compound (4b) was concluded as the most potent compound of the series with the highest binding constant (4.95 × 104) and strongest binding affinity (-8.48 kcal/mol). Communicated by Ramaswamy H. Sarma

Structural characterization of marine macroalgae derived silver nanoparticles and their colorimetric sensing of hydrogen peroxide

The present study investigates the algae-mediated synthesis, characterization, and H2O2 sensing ability of silver nanoparticles using Sargassum spp. extract. The synthesized nanoparticles were spherical agglomerates and exhibited an absorbance peak at 418 nm, as analyzed by FE-SEM and UV–vis spectrophotometric analysis. TEM-SAED analysis interpreted the size between 2 and 35 nm and crystallinity corresponding to face-centered cubic (FCC) silver structure. This was further supported from XRD findings, which ascertained the presence of (111), (200), (220), and (311) lattice planes. FT-IR analysis confirmed the capping of algal phenolics as corresponding functional groups, which was further confirmed by XPS studies. The nanoparticles were observed to be highly stable in aqueous suspensions, due to the zeta potential value (−22.6 mV). On incubation of synthesized nanoparticles, with H2O2 solutions, decolorization of nanoparticle solution was observed along with the reduction of absorbance peak at 418 nm. This color change could be utilized for H2O2 detection in contaminated samples. Therefore, this study reveals the potential of sustainable Sargassum spp. biomass in synthesizing beneficial silver nanoparticles which could be exploited for environmental detection applications.

Assessment of Mediterranean Citrus Peel Flavonoids and Their Antioxidant Capacity Using an Innovative UV-Vis Spectrophotometric Approach

Citrus fruits exert various beneficial health effects due to the large amount of polyphenols they contain. Citrus peels, often considered food waste, contain several health-promoting polyphenols. Among these, flavonoids have long been quantified through colorimetric assays which, if not adequately applied, can lead to conflicting results. Flavonoids possess strong antioxidant properties and can decrease circulating free radicals, thereby reducing oxidative stress phenomena. Quantifying flavonoids and properly estimating their antioxidant capacity allows us to predict plausible beneficial effects of citrus fruits on human health. The aim of this research was to analyze the advantageous phenolic compounds found in the peels of citrus fruits commonly found in the Mediterranean region. The objective was to measure their antioxidant capacity and ability to neutralize free radicals. To achieve this purpose, UV-visible spectrophotometric analyses, liquid chromatography (LC) and Electron Paramagnetic Spectroscopy (EPR) were utilized and compared, finally suggesting an innovative approach for assessing the overall flavonoid content by the nitrite-aluminum assay. HPLC data demonstrated that hesperidin was the most abundant flavonoid in all peel extracts except for orange peels, in which naringin was the predominant flavonoid. The total flavonoid content was greater than 1.3 mg/mL in all extracts, with tangerine and orange yielding the best results. Citrus peel polyphenols exerted strong antioxidant and free radical scavenging effects, inhibiting up to 75% of the free radicals used as reference in the EPR analyses.

Biosynthesis of silver nanoparticles using aqueous extract of Lepidium meyenii and testing their antimicrobial activity

Lepidium meyenii herb (maca) belongs to the cruciferous family that includes broccoli, radish, watercress, cabbage and turnip. It is also available as a dietary supplement in the form of capsules and liquid extracts. Silver nanoparticles were made using the aqueous extract of maca root for the first time locally and worldwide. As a reducing agent, the extract was utilized. Several approaches were used to diagnose silver nanoparticles, including scanning electron microscopy, atomic force microscopy, FT-IR and UV-vis spectrophotometer analyses. The diagnostic results showed the formation of nanoparticles in various shapes, with a diameter ranging from 56.11 nanometers. The optimum conditions for the bio-synthesis of silver nanoparticles were determined. The optimal conditions were pH 7, 37 °C, with a concentration of 1 mmol silver ions. These are the ideal conditions for making silver nanoparticles from L.meyenii. The antibacterial effectiveness of biosynthesized AgNP against Staphylococcus aureus was found to be very significant. This work promotes green synthesis of AgNP for a range of applications that require low toxicity and are ecologically friendly.