UV-Vis Spectrophotometer Research Articles

Applicability of Ni@ZnO polymer nanocomposite as an adsorbent for removal of methylene blue dye from synthetic wastewater: Batch studies and multilinear regression (MLR) modeling.

Synthetic organic dye such as methylene blue (MB) is non-biodegradable and highly toxic, released from textile wastewater. This work investigates the applicability of Ni@ZnO polymer nanocomposite for MB removal from the wastewater. To understand their differences before and after MB adsorption, composites' surface morphology was characterized by various techniques including scanning electron microscope (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), Fourier transformation infrared (FT-IR) and UV-Vis spectrophotometer. The adsorption mechanism of target pollutants by the composites was also studied based on isotherm and kinetic models. The correlation between the optimized conditions and the percentage removal was further studied by applying multi linear regression (MLR) model. At the same concentration of 100mg/L, it was found that under optimized conditions of 1g/L of adsorbent, pH 7.5, and 190min of reaction time, about 94% and 98% of MB removal were attained, respectively. Inspite of thepromising results, treated effluents were still unable to meet the required discharge standards of less than 1mg/L mandated by local legislation. Furthermore, the MB adsorption by the composite was based on attractive electrostatic interactions. Overall, this study not only provides insights into the adsorption efficiency, but also evaluates the recyclability and stability of the adsorbent, addressing key challenges in practical wastewater treatment. By integrating its novel aspects, this work contributes to a more nuanced understanding of the Ni@ZnO composite's potential in environmental applications, distinguishing this work from existing literature on MB adsorption.

Response surface methodology for glucose conversion by applying deep eutectic solvent (DES) as green solvent

Glucose is a monosaccharide-type carbohydrate that serves as a fundamental building block of biomass. In this research, glucose was hydrolyzed using a Deep Eutectic Solvent (DES) as the solvent and AlCl3 as the catalyst. The effects of temperature and catalyst concentration were investigated as key variables in the reaction. The glucose conversion results were tested using the UV-Vis spectrophotometer. The yields of glucose conversion were analyzed using the Response Surface Methodology (RSM) with Design Expert Version 13 software. The results of RSM analysis show that glucose conversion increases linearly with rising reaction temperature. The effect of catalyst concentration indicates that glucose conversion decreases at higher catalyst levels. The reaction temperature and AlCl3 catalyst concentration that can be recommended for optimum conditions from the Design Expert data processing results are 112.869 C and 1.913% with a predicted conversion value of 93.844%.

Removal of methyl orange in Aqueous Media using two clays from Côte d'Ivoire

This work used Boundiali and Man clays to eliminate methyl orange in an aqueous medium. These clays were activated with hydrochloric acid and then characterized by scanning electron microscopy, X-ray diffractogram, Brunauer–Emmett–Teller (BET) method, and zero charge pH. Methyl orange concentration was monitored during adsorption using a UV-visible spectrophotometer. Characterization showed that the clays have many micropores, mesopores, and few macropores. The specific surface areas of these clays are equal to 39,084 m2 g-1 and 39,722 m2 g-1 for Boundiali and Man clays, respectively. These clays are composed of kaolinite, illite, and quartz. They have non-uniform morphologies and display irregularly shaped flaky particles of different sizes. The surface pH of Boundiali clay is neutral, while Man clay's is essential. Adsorption of methyl orange on these clays conforms to pseudo 2nd order kinetics with 60 minutes as the equilibrium time. Adsorption is favorable in acidic media and spontaneous at room temperature with both types of clay. The Boundiali clay has an adsorption capacity of 40.486 mg g-1, and the Man clay has an adsorption capacity of 38.610 mg g-1.

Fabrication of Cu: ZnO thin film sensor for ethanol vapor detection

For a long time, metal oxide semiconductor (MOS) based gas sensors have been widely used in domestic, commercial, and industrial sectors to detect harmful gases. The performance of such sensors is significantly enhanced by appropriate doping of suitable materials into MOS such as ZnO and SnO2. This work showcases the design, analysis, and use of a Cu-doped ZnO (Cu: ZnO) film tailored for detecting traces of ethanol vapor at lower temperatures. Herein, various Cu: ZnO films have been fabricated on glass substrates using a spin coater followed by annealing at 600 for 1 hour in a muffle furnace. So-prepared samples have been characterized using X-ray diffraction, Energy Dispersive Analysis X-ray (EDAX), UV-visible spectrophotometer, and Scanning Electron Microscopy (SEM). The XRD analysis showed a polycrystalline nature with preferred orientation along (100) and (002) crystal planes. The morphology study showed their porous and granular surface structure. These films' elemental analysis demonstrated the good incorporation of Cu into the ZnO matrix. The UV-visible results showed a significant decrease in the band gap from 3.28 eV for undoped ZnO to 3.20 eV for Cu: ZnO films. Ultimately, as-prepared Cu: ZnO thin films were used for sensing ethanol vapor at temperatures ranging from 100 to 300 . The result showed a maximum sensitivity of 70.60 at a reduced temperature of 140 at 4% Cu: ZnO thin, which implies that Cu: ZnO is suitable for developing the gas sensors for upcoming future generations.

Syzygium cumini-Mediated NPs Exhibiting Antibacterial, Anti-Motility, and Anti-Biofilm Potential against Multi-Drug Resistant Clinical Nosocomial Pathogens

Introduction: Multidrug resistance in nosocomial pathogens is now a serious problem in the health care system and causes the majority of morbidity and death worldwide. The current landscape of antibiotic failures encourages researchers to look for plant-based (green synthesized) nanoparticles (NPs). Therefore, the present study aims to synthesize silver NPs (AgNPs) using the leaf extract of Syzygium cumini (S. cumini) and assess their antibacterial, anti-motility, and anti-biofilm potential against two multi-drug resistant (MDR) clinical isolates, i.e., P. aeruginosa and A. baumannii. Methodology: Optimization of reaction parameters for NPs synthesis was carried out using a UV-Vis spectrophotometer. After optimization, these NPs were characterized through UV-Vis, Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), XRay Diffraction (XRD), Selected Area Electron Diffraction (SAED), and ThermoGravimetric Analyzer (TGA). These NPs were then checked for antibacterial, anti-motility, and anti-biofilm activity. Results: The spectrum of optimized AgNPs was noticed at 432 nm, displaying a bell-shaped curve under UV-Vis spectroscopy. TEM images showed biosynthesized NPs have a spherical shape and 15-20 nm diameter. The FT-IR study has revealed the presence of phenolics, aromatics, and alkyne groups in the synthesized NPs. These biosynthesized AgNPs were processed for antibacterial, anti-motility, and anti-biofilm activity. Results showed that AgNPs exhibit good antibacterial activity. The effect of AgNPs against P.aeruginosa and A. baumannii showed a substantial reduction in motility patterns and biofilm architecture. A one-way ANOVA statistical test was used that displayed a significant difference (p-value<0.001) in MIC, motility, and biofilm inhibition assay. Conclusion: Based on the findings, AgNPs showed promising antibacterial, anti-motility, and antibiofilm activity against both MDR clinical strains. However, identifying the active compound and using its NPs in vivo and in animal experiments may add to their future applicability.

TiO2/SWCNts: Linear and Nonlinear Optical Studies for Environmental Applications

A series of single-walled carbon nanotube/titanium dioxide (SWCNTs/TiO2) composites were prepared by the incorporation of various concentrations (0, 5, 10, 20 V.%) of SWCNTs in TiO2. The prepared solutions were successfully formed on silicon and quartz substrates using the sol–gel spin-coating approach at 600 °C in ambient air. The X-ray diffraction method was used to investigate the structure of the samples. The absorbance and transmittance data of the samples were measured using a UV–vis spectrophotometer. Through the analysis of these data, both the linear and nonlinear optical properties of the samples were examined. Wemple–DiDomenico’s single-oscillator model was used to calculate the single-oscillator energy and dispersion energy. Finally, all samples’ photocatalytic performance was studied by the photodegradation of methylene blue (MB) in an aqueous solution under UV irradiation. It is found that the photocatalytic efficiency increases when increasing the SWCNT content. This research offers a new perspective for the creation of new photocatalysts for environmental applications.

UJI ANALISIS KUALITATIF DAN KUANTITATIF KADAR VITAMIN C PADA SEDIAAN KOSMETIK LOTION YANG BEREDAR DI KAB. MAROS DENGAN METODE SPEKTROFOTOMETER Uv-Vis

Cosmetics are an inseparable part of women's lives in particular and are used every day. Lotions are widely used to moisturize the skin and to brighten the skin. Lotion can be used for all skin types for teenagers aged 15 years and over. Vitamin C has various benefits, including as an antioxidant against pollution, sun exposure, brightening the skin, delaying the effects of aging, and increasing collagen formation which makes the skin supple, smooth and bright. The aim of the research was to determine the vitamin C content in cosmetic lotions according to the standards/labels circulating in the Maros district. The research was carried out using qualitative analysis methods in the pharmaceutical chemistry analysis laboratory of STIKes Salewangang Maros where the samples were lotion cosmetic products containing vitamin C at kab. Maros as stated on the product packaging/label and analyzed using a Uv-Vis spectrophotometer. The results of the research obtained showed that all lotion cosmetic preparations contained vitamin C with different percentage levels for each concentration, where lotion samples that did not have a distribution permit obtained high levels of Vitamin C, while lotions that had a distribution permit showed high levels of Vitamin C. not excessive, so it is safe to use for a long time.

Structural, morphological and biological assessment of magnetic hydroxyapatite with superior hyperthermia potential for orthopedic applications

Hydroxyapatite (HA) is an important constituent of natural bone. The properties of HA can be enhanced with the help of various ionic substitutions in the crystal lattice of HA. Iron (Fe) is a vital element present in bones and teeth. In this study, iron-doped HA was synthesized using a refluxing-based sol-gel route with varying concentrations of iron (1–9 M%). Samples were analyzed using an X-ray diffractometer (XRD), UV–Vis Spectrophotometer, Fourier-transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM) and Scanning Electron Microscope (SEM). The biological assessment was carried out by hemolytic assay, anti-bacterial activity and in-vitro biocompatibility. XRD data confirmed the evolution of the hexagonal HA crystal structure with the reduction in the crystallinity and the crystallite size. All the characteristic bands were confirmed using FT-IR which also further proved the existence of A-type carbonated apatite. The UV–Vis spectra confirmed the reduction in the band gap energies owing to the substitution of iron. The SEM results showed a change in the shape of the samples with increasing iron concentration. The magnetic behavior of samples also altered from diamagnetic to ferromagnetic behavior due to the doping of iron with enhanced heating efficiency. All the samples were found to be hemocompatible. The antibacterial efficacy was found to be higher for E. coli (gram-negative) bacteria compared to S. aureus (gram-positive) bacteria. Moreover, the superior cell viability of MG-63 (osteoblast-like) cells was observed in Fe-doped HA, attributed to MTT assay which revealed the enhanced cell viability of osteoblast-like cells in the Fe-doped HA. These results strongly emphasize the potential of the developed samples for bone regeneration applications.

Thymoquinone-loaded Nanosized Ethosomal-based Hydrogels: Their Preparation, Characterization, in Vitro, Ex Vivo, and Antimicrobial Evaluation against Staphylococcus aureus.

Thymoquinone (TQ) is found in the seeds of Nigella sativa. It has immunomodulatory, antibacterial, anti-inflammatory, antioxidant, astringent, antifungal, and antihistaminic properties, making it a highly valuable compound of interest. However, the use of it as a therapeutic drug is highly challenging because of its poor solubility, low bioavailability, and short-term stability. The present study focused on a nanosized ethosome formulation of thymoquinone with potent antimicrobial activity against Staphylococcus aureus. This study aimed to develop nanosized TQ-loaded ethosome-based hydrogels and evaluate their antimicrobial effects. The methods included UV‒VIS spectrophotometer analysis, solubility studies, preparation of TQ-loaded ethosomes, thermodynamic stability, in vitro drug release, characterization, preparation of ethosome- based hydrogels, ex vivo skin permeation, skin drug retention, and antimicrobial studies against S. aureus. UV‒VIS analysis revealed that thymoquinone (TQ) demonstrated a maximum absorbance peak at λmax 254 nm. TQ has the highest solubility in ethanol (60 mg/mL) and soy lecithin (65 mg/mL). TQ solubility in PBS 7.4 (75 mg/mL) with ethanol (50:50% w/v) was found to be crucial for determining in vitro and ex vivo drug release. Ethosomes were developed using soy lecithin (1.5-4.5% w/w), cholesterol (0.20-0.42% w/w), and ethanol (30-47% w/w) across ten formulations (E1-E10). These ethosomes were further evaluated for physical stability. Formulations E6-E10, with optimal concentrations of soy lecithin, cholesterol, and high ethanol, showed thermodynamic stability for up to 6 weeks. These materials were selected for further study because of their stability and in vitro drug release. E6 resulted in the greatest drug release and permeation due to the optimal lipid, cholesterol, and higher ethanol concentrations. E6, with a particle size of 114.8 nm, a PDI of 0.247, and a zeta potential of -0.497 mV, showed optimal stability and drug encapsulation, and the TEM results confirmed the presence of spherical vesicles. The addition of carbopol-940 (1% w/w) resulted in the formation of a gel, enhancing the topical application and sustained release of the drug. Compared with the TQCG hydrogel, the E6 hydrogel showed superior TQ permeation and flux over 24 hours. The first-order model fits the release kinetics, confirming the suitability of the E6 hydrogel for further study. The E6 hydrogel retained 3.6 times more drugs than TQ-CG, enhancing skin penetration and drug delivery. The TQ-loaded ethosome (E6 in D3) demonstrated the second-highest antimicrobial action, followed by the E6 hydrogel [D2], with the Clinsol gel as a control [C] showing the maximum inhibition against S. aureus. The efficacy of E6 is likely due to better diffusion. The slower diffusion of the hydrogel provides sustained action, making it effective for prolonged topical drug delivery. The E6 hydrogel shows promise for local therapeutic benefits and sustained drug release and could be a superior herbal option for managing skin infections.

Structural and Optical Properties of Hydrothermally Synthesized Co0.3Zn0.7AlxFe2−𝑥O4 (x = 0.2 – 0.8) Nanoparticles

Objectives: Investigations on structural and optical studies of Co0.3Zn0.7AlxFe2-xO4 (x = 0.2 – 0.8)/CZAFO nanoparticles synthesized through hydrothermal method are presented in this paper. Methods: Co0.3Zn0.7AlxFe2-xO4 (x = 0.2 – 0.8) samples are synthesized by hydrothermal method. Structural and Optical characterization of the samples is done by using X-ray diffraction (XRD), photoluminescence (PL), UV-Vis spectrophotometer and Fourier transform infrared spectroscopy (FTIR). Findings: The spinel cubic structure is established with the X-Ray Diffraction pattern. The crystallite size values range from 5.610 to 6.188 nm increasing with substitution Al3+ concentration x, according to the Debye-Scherer formula. Photoluminescence emission between 360 nm and 615 nm exposes the radiative deficiencies and oxygen vacancies by the effect of Al3+ substituting CZFO nanoparticles at room temperature. FT-IR confirms the existence of metal oxides. Using the UV-visible spectrophotometer and the impact of Al3+ substitutions on Co-Zn ferrite nanoparticles, optical energy band gap in the samples was investigated. Samples' energy band gap decreases as the Al3+ content rises, from x = 0.2 to 0.8. Novelty: Investigations on the effect of Al substitution on structural and Optical properties of Co0.3Zn0.7AlxFe2-xO4 nanoparticles were optical band gap energies ranging from 1.647 eV to 1.487 eV, depending on the composition (x = 0.2, 0.4, 0.6, and 0.8), hold promise for sort of optoelectronic applications and including photocatalysis, optical sensors and biomedical imaging. Also, optical band gap energy (Eg) values were provided to indicate the semiconductor nature of CZAFO nanoparticles. Keywords: Aluminum, Nanoparticles, Hydrothermal Method, Optical Property, Cobalt-Zinc ferrite (CZFO)

Pre-Treatment and Characterization of Water Hyacinth Biomass (WHB) for Enhanced Xylose Production Using Dilute Alkali Treatment Method

Lignocellulosic biomass from water hyacinth, a readily available waste material, holds potential for producing commercial products such as xylose, which can be further converted into value-added products like xylitol. However, the complex structure of lignocellulosic biomass necessitates energy-intensive processes to release fermentable sugars. Chemical pre-treatment methods, such as alkali pre-treatment, offer a viable approach to degrade lignocellulose biomass. In this study, water hyacinth biomass (WHB) was treated with 3% potassium hydroxide and subjected to autoclaving to hydrolyse the sample. The total xylose released during the process was quantified using a UV-Vis spectrophotometer and was found to 0.253 g/g of water hyacinth biomass when the sample was treated for 20 min at 2% biomass concentration. The morphological changes in the treated biomass compared to the untreated sample were analysed using Field Emission Scanning Electron Microscopy (FE-SEM). Crystallinity alterations were evaluated through X-Ray Diffraction (XRD), while Fourier-Transform Infrared Spectroscopy (FTIR) was employed to study the changes in chemical states of the biomass. The primary objective of this study was to identify a reliable pre-treatment method for processing water hyacinth biomass, facilitating the efficient release of fermentable sugars for downstream applications.

Studying the effect of concentration on spectral and optical properties of chitosan polymer

Due to its noteworthy physico-chemical behaviors, the chitosan (CS) biopolymer presents a compelling alter-native to conventional biomaterials. By measuring the emission spectra at a spectrofluorophotometer in differ-ent concentrates (1x10-4, 1x10-5, and 1x10-6) M, the spectral characteristics of the CS polymer were obtained. The crystallinity of the CS polymer was determined by X-ray diffraction (XRD) analysis, which shows only one dominant peak indexed to the orthorhombic structure. With a drop in solution concentration, there was a shift toward the shorter wavelength and a decline in quantum yield. Using a UV-Vis spectrophotometer, the optical properties of the CS polymer, including its refractive index, absorption coefficient, energy band gap, extinction coefficient, and dielectric constant, have been studied. It was observed through the results that the optical parameters are linearly dependent with concentration. In contrast to the optical energy gap, which de-creases with increasing concentration.

Role of Novel Chlorella vulgaris SSAU8 in Improving the Soil Health Under Induced Drought Stress.

The severe climate change has caused a drastic water level disparity around the globe, which eventually has been one of the biggest problems of this era related to land degradation. This has caused the multidimensional impact on ecology, the environment, and their components. Algae, one of the ancient micro-engineers, are involved in the functioning of soil microcosm. Therefore, this study has utilized a novel alga, Chlorella vulgarisSSAU8 to observe the impact of low water potential induced by PEG-6000 (polyethylene glycol). The study has utilized the UV-Vis spectrophotometer to explore the nature of cyanobacteria by examining biomass and pigment concentrations. The assessment also includes the photosystem response, which was recorded by the Dual-modulation kinetic fluorometer FL3500/F (PSI, Brno, Czech Republic, version 3.7.0.1). The effect of PEG-6000-induced drought was seen to inhibit growth and biomass synthesis at > 30gL-1 concentration. It was also observed that the microbe could easily shuffle its photosystem behavior to nullify the effect of high PEG-6000 concentration, which shows the potential of the microbe in the water-deficient area and can be an important aspect to enhance soil fertility. Non-photochemical quenching and heat dissipation play a crucial role in cyanobacteria tolerating drought conditions. So, overall, this study thoroughly explores the behavior of Chlorella vulgarisSSAU8 in artificial drought stress and paves a way to combat one of the major environmental issues of the current era.

EVALUATION OF ANTIOXIDANT ACTIVITY OF EXTRACT COMBINATION OF GINGER AND LEMONGRASS

Aim and objective: This study to determine the antioxidant activity of the combination of ginger (Zingiber officinale) and lemongrass (Cymbopogon citratus) on reducing DPPH (2,2-diphenyl-1-picrylhydrazyl). Methods: Quantitative measurement of the antioxidant activity of ginger and lemongrass extracts, as well as a combination of both with a concentration ratio of 1:1, 2:1, 1:2 using a UV-Vis spectrophotometer at a wavelength of 516 nm to determine the IC50 value. Results: IC50 value of ginger extract 10.76 µg/mL, lemongrass extract 26.69 µg/mL, IC50 value 6.69 µg/mL for combination with concentration ratio 1:1, IC50 value 3.32 µg/mL for combination with concentration ratio 2:1. IC50 value 9.34 µg/mL for combination with concentration ratio 1:2 Conclusions: The combination of ginger and lemongrass extracts has synergistic antioxidant activity that can increase the antioxidant effect from the strong category to very strong category. Peer Review History: Received 17 October 2024; Reviewed 9 November; Accepted 18 December; Available online 15 January 2025 Academic Editor: Dr. Ahmad Najib, Universitas Muslim Indonesia, Indonesia, ahmad.najib@umi.ac.id Average Peer review marks at initial stage: 5.5/10 Average Peer review marks at publication stage: 7.0/10

Visual detection of kanamycin with functionalized Au nanoparticles.

A simple and rapid colorimetric detection strategy, based on hydrogen bond identification of 6-thioguanine (6-TG) functionalized Au nanoparticles (AuNPs), is proposed for highly selective and sensitive determinationof kanamycin (KA). In this strategy, the hydrogen bond interaction between 6-TG and kanamycin induces AuNPs to agglomerate, with a consequent color change of AuNPs from wine red to purple or even blue. The kanamycin concentrations can be quantified by employing UV-vis spectrophotometer. The results display that kanamycin concentrations (0.005 to 18µM) are linearly related to A620/A520 (the absorbance ratio of 620nm and 520nm) with a LOD of 1.8nM and a LOQ of 5.9nM (S/N = 3). This strategy also reveals a high degree of selectivity among a series of common interfering species. Moreover, the strategy can be employed to detect trace amounts of kanamycin in real-life samples, and it shows satisfying resultscompared with high performance liquid chromatography. In general, this developed strategy is facile and inexpensive without the need for complex processing procedures and expensive instruments. In addition, this work may further exploit detection strategies for other organic contaminants, as well as make a strong contribution to the development of the colorimetric method.

Comparative Evaluation of Surface Roughness and Color Stability of Polyetheretherketone with Conventional Interim Prosthetic Materials: An In Vitro Study.

The aim of this in vitro study was to compare the surface roughness and color stability of polyetheretherketone (PEEK) with those of conventional interim prosthetic materials like polymethylmethacrylate, bis-acrylic composite, and rubberized diurethane dimethacrylate, following immersion in solutions of varying pH value. A total of 320 circular discs with 10 mm diameter and 2 mm height were divided based on the fabrication (n = 80)-group A: polymethylmethacrylate; group B: bis-acrylic composite; group R: rubberized diurethane; and group P: hot-pressed PEEK-and were subjected to baseline measurement of roughness (n = 40) and color (n = 40) using 3D profilometer and UV-Vis spectrophotometer, respectively. Later, 10 samples from each group were immersed in distilled water, black coffee, green tea, and Pepsi, respectively, for 120 days, and measurements of roughness and color were repeated. The differences in roughness (ΔRa) and color change(ΔE) were calculated and statistically analyzed with a significance level of p-value < 0.05. Irrespective of the immersion solution, the highest mean difference in the roughness values was shown by rubberized diurethane specimens: ΔRa = 3.574880 (0.0048350) in carbonated beverages, and lowest difference was shown by bis-acrylic composite: ΔRa = 0.29004 (0.0017473) in distilled water. The greatest color stability was exhibited by PEEK. The type of interim material and immersion solution had a statistically significant effect on change in color and roughness values. The immersion in solutions of varying pH had a significant effect on surface roughness and color stability of all the tested materials. The Ra value of all specimens after immersion was still within the clinically acceptable range. Polyetheretherketone was the most color stable material in all solutions, except in green tea. This study will provide guidance to dentists and patients regarding the selection of interim material for long-term use, depending on the effect of beverage consumption on its color stability and roughness. How to cite this article: Saraswathy A, Latha N, Ayyadanveettil P, et al. Comparative Evaluation of Surface Roughness and Color Stability of Polyetheretherketone with Conventional Interim Prosthetic Materials: An In Vitro Study. J Contemp Dent Pract 2024;25(10):930-935.

Genetic determinants of silver nanoparticle resistance and the impact of gamma irradiation on nanoparticle stability

BackgroundOne of the main issues facing public health with microbial infections is antibiotic resistance. Nanoparticles (NPs) are among the best alternatives to overcome this issue. Silver nanoparticle (AgNPs) preparations are widely applied to treat multidrug-resistant pathogens. Therefore, there is an urgent need for greater knowledge regarding the effects of improper and excessive use of these medications. The current study describes the consequences of long-term exposure to sub-lethal concentrations of AgNPs on the bacterial sensitivity to NPs and the reflection of this change on the bacterial genome.ResultsChemical methods have been used to prepare AgNPs and gamma irradiation has been utilized to produce more stable AgNPs. Different techniques were used to characterize and identify the prepared AgNPs including UV-visible spectrophotometer, Fourier Transform Infrared (FT-IR), Dynamic light scattering (DLS), and zeta potential. Transmission electron microscope (TEM) and Scanning electron microscope (SEM) showed 50–100 nm spherical-shaped AgNPs. Eleven gram-negative and gram-positive bacterial isolates were collected from different wound infections. The minimum inhibitory concentrations (MICs) of AgNPs against the tested isolates were evaluated using the agar dilution method. This was followed by the induction of bacterial resistance to AgNPs using increasing concentrations of AgNPs. All isolates changed their susceptibility level to become resistant to high concentrations of AgNPs upon recultivation at increasing concentrations of AgNPs. Whole genome sequencing (WGS) was performed on selected susceptible isolates of gram-positive Staphylococcus lentus (St.L.1), gram-negative Klebsiella pneumonia (KP.1), and their resistant isolates St.L_R.Ag and KP_R.Ag to detect the genomic changes and mutations.ConclusionsFor the detection of single-nucleotide polymorphisms (SNPs) and the identification of all variants (SNPs, insertions, and deletions) in our isolates, the Variation Analysis Service tool available in the Bacterial and Viral Bioinformatics Resource Center (BV-BRC) was used. Compared to the susceptible isolates, the AgNPs-resistant isolates St.L_R.Ag and KP_R.Ag had unique mutations in specific efflux pump systems, stress response, outer membrane proteins, and permeases. These findings might help to explain how single-nucleotide variants contribute to AgNPs resistance. Consequently, strict regulations and rules regarding the use and disposal of nano waste worldwide, strict knowledge of microbe-nanoparticle interaction, and the regulated disposal of NPs are required to prevent pathogens from developing nanoparticle resistance.

Green Synthesis and Characterization of Fe Nanoparticles Using Neem (Azadirachta indica L.) Leaves

A laboratory study for synthesis and characterization of iron nanoparticles was conducted at laboratory of Department of Nanotechnology and Centre for advanced Research in Plant Tissue Culture, Anand Agricultural University, Anand. The Fe nanoparticle synthesized by green method and subsequently characterized for size (Dynamic Light Scattering), functional group (FTIR) and absorbance spectra (UV-VIS Spectrophotometer). The hydrodynamic average diameter was 22.02 nm, Polydispersity index (Pdi) of 0.248 and Kilo count per second (Kcps) of 228.6 for Fe nanoparticles. The FTIR showed 3219.06 cm−1, 1637.15 cm-1 confirmed presence of Fe nanoparticles. The UV-Visible spectra of the green synthesized Fe nanoparticles found an absorption peak at 256 nm. The FeCl3.6H2O and the neem leaf extract reacted, the color of the reaction mixture quickly changed from yellow to a dark brown color.

Analyzing Aloe vera and Avocado Seed Extracts for Antioxidants, Saponins, Tannins, Flavonoids, and Alkaloids Using the UV-VIS Spectrophotometric Method

Background This study sought to quantify the levels of saponins, alkaloids, flavonoids, and tannins, as well as the IC50 values of avocado seed and aloe vera extracts. Methods The materials included in the investigation consisted of 70% ethanol extracts derived from avocado seeds and Aloe vera. Both samples underwent quantitative phytochemical analyses to ascertain total component content and an antioxidant activity assessment utilizing the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) technique to evaluate % inhibition and IC50 values. The absorbance of the samples was quantified using a UV-Vis spectrophotometer, which facilitated the calculation of total chemical content and antioxidant activity. Results The avocado seed extract comprised saponins, alkaloids, flavonoids, and tannins at concentrations of 0.21%, 0.0232%, 19.94%, and 10.66%, respectively, with an IC50 value of 135 μg/mL. The aloe vera extract comprises saponins, alkaloids, flavonoids, and tannins at concentrations of 0.74%, 0.0313%, 0.99%, and 4.68%, respectively, with an IC50 value of 4614 μg/mL. Conclusion Avocado seeds exhibited elevated levels of flavonoids and tannins, while aloe vera demonstrated increased concentrations of alkaloids and saponins. In the antioxidant activity assessment, avocado seeds demonstrated superior antioxidant efficacy.

In-vitro study of hybrid silver nanoparticles with humic acid extracted from cow dung against pathogens.

Recently, researchers have used silver nanoparticles (AgNPs) coupled with humic acid (HA) as antimicrobial agents. Herein, AgNPs were prepared and coupled with humic acid for their antimicrobial activities. The as-prepared AgNPs coupled with humic acid (HA) were characterized by an atomic force microscope (AFM), X-ray powder diffraction (XRD), zeta potential, zeta sizer, Fourier-transform infrared (FT-IR) spectroscopy, and UV-VIS spectrophotometer. Moreover, human plasma, varied salt concentrations, and pH levels were used for stability confirmation using a UV-VIS spectrophotometer. The antibacterial activities and minimal bactericidal concentration (MBC) of coupled AgNPs were determined by disk diffusion and broth dilution methods, respectively, against identified Staphylococcus aureus, Streptococcus pyogene, Pseudomonas aeruginosa, and Escherichia coli, which are extracted from cow dung. AgNPs' peak in the UV-Vis spectral range showed maximal absorption at 415nm. The coupled AgNPs displayed their distinctive peak under all circumstances, demonstrating their stability. The FT-IR displayed functional groups such as hydroxyl, carboxylic acids, carbonyl, ester, and ether groups. The particles were face-centered cubic (FCC) in structure, according to the XRD. Moreover, particles had a spherical shape, high negative zeta potential, and were polydisperse in nature, with an average size of 25.43nm. The minimal bactericidal concentration (MBC) of AgNPs was found to be 2.5mg/mL, and the MBC of AgNPs/HA was found to be 5mg/mL. The result indicated that the as-synthesizedAgNPs/HA are more effective in inhibiting all the studied microorganisms, which can be attributed to the therapeutic use of nanoparticles coated with humic acids.