UV Vis Spectroscopy Research Articles

Magnetic solid-phase extraction of amoxicillin and doxycycline from water and urine samples based on cetylpyridinium chloride-modified Fe3O4 nanoparticles followed by spectrophotometric determination.

This research describes an easy, rapid, and inexpensive magnetic solid-phase extraction (MSPE) approach employing Fe3O4 magnetic nanoparticles modified with cetylpyridinium chloride (Fe3O4@CPC/MNPs) for extracting amoxicillin (AMX) and doxycycline (DOX) after derivatization with 4-chloroaniline as a color reagent. The azo-coupling of AMX and DOX with the color reagent in the alkaline medium caused yellow and yellow-orange azo dyes with maximum absorption wavelengths of 435 and 438 nm, respectively. The UV-Vis spectroscopy was utilized to determine the target analyte after the extraction procedure. Good linearities (R2 > 0.99) in the concentration ranges of 0.03-4.50 and 0.05-6.00µg/mL were obtained for AMX and DOX, respectively. The experimental detection limits of AMX and DOX were obtained as 0.01 and 0.02 µg/mL, respectively. The developed approach was effectively applied to pre-concentrate and quantify AMX and DOX in environmental water and urine samples.

Anticancer, Antioxidant and Antimicrobial Evaluation of Cr (III) and Rh(III) Complexes Derived from A New Mannich Base

The Mannich base ligand was synthesized in an ethanol medium through a condensation reaction of 2-mercaptobenzimidazole and ciprofloxacin at room temperature. Subsequently, several metal complexes of this ligand were prepared. To characterize both the base ligand and the metal complexes, various techniques were employed, including elemental analysis, FT-IR spectroscopy, UV-Vis spectroscopy, molar conductivity measurements, magnetic moment determination, and melting point analysis. The results were shown that the metal complexes formed have the formula [Cr(L)2Cl2] Cl.H2O and [Rh(L)2(H2O)2] Cl3.H2O, where L= mannich base ligand. Based on spectroscopic analytical, coordination with metal ions involves the 'N' donor atom of mannich base and 'N' atom of piprizaing ring, and two complexes are A six-coordinated octahedral structure is suggested. Molar conductivity of these complexes showed that they were electrolytic in nature. In this study, the anticancer and antioxidant potential of the Mannich base ligand and its metal complexes were investigated against MDA-MB-231 cell lines and using the DPPH free radical scavenging assay. Moreover, the in vitro efficacy of the ligand and its complexes against Gram-negative bacteria (E. coli) and Gram-positive bacteria (Staphylococcus aureus), as well as the fungal strain Candida albicans, was evaluated using the disc diffusion method. The results indicated that Cr (III) and Rh(III) complexes demonstrated the highest levels of cytotoxicity against MDA-MB-231 cell lines, enhances antioxidant and antimicrobial activity more than the free ligand. These findings suggest that these metal complexes may have promising applications in the development of novel anticancer, antioxidant and antimicrobial agents.

A Simple Dispersive Liquid-Liquid Microextraction for the Determination of Copper II in the Water Samples of the Halfaya Oil Field in Maysan

Background: Copper, an important trace element for life on Earth, is crucial to many metabolic processes. This includes its role in the production and breakdown of nucleic acids and the metabolism of proteins, lipids, and carbohydrates. Objective: We aim to integrate DLLME with a spectrophotometric method to establish a novel approach for quantifying trace amounts of copper in water samples. Methods: In this study, a new ligand known as a 2-(4 aminophenol) benzimidazole azo derivative was successfully synthesized. This ligand was created by converting 2-(4-aminophenyl) benzimidazole into a diazonium salt and coupling it with 8-hydroxyquinoline in an alkaline environment. The resulting product was a brown azo dye, which served as the ligand for detecting copper (II) in aqueous samples. Results: To analyze copper (II) in both pure and aqueous samples, we developed and validated micro-extraction techniques combined with UV-Vis measurement. Specifically, we used the DLLME (dispersive liquid-liquid microextraction) method to separate, enrich, and assess copper (II) in both its pure form and in aqueous samples. UV-Vis spectroscopy at a wavelength of 503 nm was used for this purpose. We considered several variables during the experiment, including the type and volume of the dispersive solvent, the extraction solvents, the temperature, the reaction duration, and the centrifuging time. By optimizing these conditions, we achieved linear procedures within the concentration range of (1.0–25.0) and (2.0–25.0) μg/mL for spectroscopy and DLLME methods, respectively. For the spectroscopic and DLLME approaches, the coefficient of determination (R2) was found to be 0.9963 and 0.9979 for the spectrophotometric and DLLME methods, respectively. The limit of detection (LOD) for copper (II) was found to be 0.23 and 0.04 μg/mL, respectively. Moreover, the recovery of the target analyte in aqueous samples was found to be between 95.6% and 101% for the spectroscopy method and between 102.4% and 108.2% for the DLLME method. Conclusions: These results demonstrate the effectiveness and accuracy of both methods in analyzing copper (II) in aqueous samples.

Photoluminescent carbon colloids prepared by laser fragmentation of carbon from waste coffee grounds

Colloidal suspensions of carbon nanostructures (CNSs) were prepared by laser fragmentation in various liquid media using heat-treated coffee grounds as carbon precursor. A study by calorimetry was done in powder of waste coffee grounds to determine the temperature of obtaining carbon. The experiments were carried out in two stages, the first one consisted in obtaining the carbon source, for which powder of waste coffee grounds was thermally treated in air. The as-obtained carbon was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, Raman spectroscopy and infrared spectroscopy. In the second step the as-obtained carbon was separately dispersed in four liquid media (acetone, toluene, methanol and isopropyl alcohol) to be fragmented by using a ns-pulsed Nd:YAG laser at its 1064 nm fundamental emission. The morphological features of the carbon nanostructures were obtained by transmission electron microscopy, while the optical properties of the colloidal suspensions were characterized by UV-Vis and photoluminescence spectroscopies. Results indicate that carbon nanostructures are successfully obtained in the four liquid media after the fragmentation process. The four colloidal suspensions show photoluminescent properties, which are seen to depend on the liquid medium nature. We found that the liquid medium also influences the efficiency of the laser fragmentation.

The Effect of Annealing Temperature on the Structural Properties and Color Properties of Tin Oxide Thin Films by the Sol-Gel Method

Tin oxide thin films were produced by the (sol-gel) method, coated on glass substrates using the spin coating process, and plasticized at (200℃, 300℃, 400 ℃, 500 ℃). The required analyses, including UV-visible spectroscopy, AFM, and XRD, were carried out. In order to research the produced films' optical, structural, and color characteristics. All of the produced films possessed a tetrahedral crystalline structure, according to X-ray diffraction data. Studies using AFM technology showed that when the annealing temperature rises, transmittance falls and the rate of surface roughness increases. In this study, the CIE 1931 method was used to examine the color coordinates of tin oxide films. Three parameters related to color were measured: brightness, dominating wavelength, and purity.

Potential of CME@ZIF-8 MOF Nanoformulation: Smart Delivery of Silymarin for Enhanced Performance and Mechanism in Albino Rats.

Silymarin, an antioxidant, is locally used for kidney and heart ailments. However, its limited water solubility and less oral bioavailability limit its therapeutic efficiency. The present study investigated the enhancement of solubility and bioavailability of silymarin by loading it in Cordia myxa plant extract-coated zeolitic imidazole framework (CME@ZIF-8) against carbon tetrachloride (CCl4)-induced nephrotoxicity and cardiac toxicity in albino rats. The synthesized PEG-coated silymarin drug-loaded CME@ZIF-8 MOFs (PEG-Sily@CME@ZIF-8) were characterized by scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, UV-visible spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and zeta potential. The average crystal size of CME@ZIF-8 and PEG-Sily@CME@ZIF-8 was 12.69 and 16.81 nm, respectively. The silymarin drug loading percentage in PEG-Sily@CME@ZIF-8 was 33.05% (w/w). In the animal model with CCl4 treatment, different parameters like serum profile, enzymatic level, genotoxicity, and histopathology were assessed. Treatment with PEG-Sily@CME@ZIF-8 with different doses of 500, 1000, and 1500 μg/kg body weight efficiently ameliorated the alterations in the antioxidant defenses, biochemical parameters, and histopathological alterations and DNA damage in comparison to silymarin drug in a CCl4-induced toxicity rat model via alleviating the cellular abnormalities and attenuation of normal antioxidant enzymes levels. Moreover, the molecular mechanism of drug-silymarin interaction with the target protein was investigated. It involves the binding pockets of silymarin molecules with VEGFR, TNF-α, NLRP3, AT1R, NOX1, RIPK1, Caspase-3, CHOP, and MMP-9 proteins, elucidating the silymarin-protein interactions by the formation of hydrogen bonds and hydrophobic interactions. This study suggests that the nanodrug PEG-Sily@CME@ZIF-8 MOFs protect the kidneys and heart possibly by mitigating oxidative stress more efficiently than the conventional drug silymarin.

Influence of Wrinkle Structure on Properties of Na-doped ZnO Films

Un-doped ZnO and Na-doped ZnO (NZO) thin films with various Na doping concentrations were successfully fabricated on glass substrates by a sol-gel process. The effect of Na ions at concentrations of 0, 1, 2, 3, 4, and 5% on the crystalline structure, surface morphology, and optoelectronic properties of ZnO films was studied using appropriate measurement techniques. XRD analysis revealed a polycrystalline hexagonal wurtzite structure in the NZO films. The NZO films' average crystal size ranged from 17.7 nm to 19.6 nm. SEM micrographs showed that wrinkle network appeared in the pure and doped ZnO films due to solvent evaporation during the thermal annealing process. UV-Vis spectroscopy pointed out that the average transmittance of NZO films is as large as ca. 78%. The optical bandgap of the films varied slightly between 3.235 eV for the pure ZnO and 3.246 eV for the Na 5% doped NZO film. When Na ions were doped into the NZO films, the electrical conductivity improved. Moreover, the absorption figure of merit exhibited the largest value of 0.981 Ω-1cm-1 for the fabricated NZO films, which enables the use of these films for solar cells and for other optoelectronic applications.

Binding mechanisms of trivalent chromium on colloidal phases from ultramafic systems: Insights from batch experiments and XAS analysis

Understanding the availability and mobility of chromium is a key factor in gaining insight into the fate of chromium and thus essential for assessing the risk of contamination and developing effective remediation strategies. In the natural environment, such as ultramafic systems, which are natural pools of chromium, chromium occurs mostly in the trivalent state (Cr(III)), which is known to have a high affinity for the solid phases such as particles and colloids. However, since Cr(VI) is more toxic, the vast majority of experimental studies focus on its reduction to Cr(III), which is often considered to form (hydr)oxide precipitates due to its poor solubility. Furthermore, while the oxidation state of Cr dictates its geochemical behavior, its interaction with particles and colloids is rarely controlled or monitored. Therefore, the interaction mechanisms between Cr(III) and particles or colloids require further attention. In this study, ten mineral phases (goethite, hematite, pyrolusite, kaolinite, montmorillonite, chlorite, serpentine, fuchsite, amphibole, and chromite) and one organic phase (humic acid), relevant to chromium bearing and carrier phases in ultramafic soils, were investigated to explore their interaction with Cr(III) species. These phases were first characterized by various techniques (including XRD, XRF, SEM, and BET). Adsorption and desorption experiments of Cr(III) on these phases were then carried out, and the distribution of Cr oxidation states in both the aqueous and solid phases was carefully monitored using UV–vis spectroscopy, geochemical speciation modeling, and Cr K-edge XAS spectroscopy. With the exception of pyrolusite, where partial oxidation of Cr(III) to Cr(VI) occurred, Cr(III) was shown to persist as a single oxidation state in all experiments. Desorption analyses showed significantly low desorbed rates, which further confirmed the prevalence of Cr(III). Experimental sorption isotherm data were interpreted using the Langmuir model and its linearized form, which provides important thermodynamic characteristics of adsorbents related to their structural and surface features. This study will provide better constraints for the understanding and prediction of Cr behavior and fate in the environment, especially in ultramafic systems.

Comparison of the natural and surfactant-modified zeolites in the adsorption efficiency of sunset yellow food dye from aqueous solutions

The removal of Sunset Yellow (E110) on natural zeolite and zeolite modified with the cationic surfactant cetyl pyridinium chloride (CPC) was studied using the adsorption method. The structural characteristics of the surfactant-modified zeolite (SMZ-CPC) were investigated using X-ray diffraction(XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) analysis, and the scanning electron microscopy (SEM) images. The effect of different parameters on the adsorption process, such as equilibration time and amount of adsorbent at 298 K, were determined using UV–Vis spectroscopy. The maximum dye removal percentage on SMZ-CPC was obtained with 0.08 g of adsorbent in 30 min. The results show that the zeolite modified with CPC surfactant (SMZ) has a higher adsorption capacity for Sunset Yellow than the unmodified zeolite (natural form). The experimental adsorption data were nonlinearly analyzed using isotherm equations such as Langmuir, Freundlich, Temkin, Langmuir-Freundlich (or Sips), and Extended Langmuir (EL). The experimental data were better fitted with the Sips isotherm. The adsorption kinetic data were analyzed using eight models in nonlinear forms: the pseudo-first-order (PFO), pseudo-second-order (PSO), integrated kinetic Langmuir (IKL), Elovich, intraparticle diffusion (IPD), mixed order rate equation (MOE), fractal-like pseudo-first-order (FL-PFO) and fractal-like pseudo-second-order (FL-PSO). According to the results of the coefficient of determination (R2), Elovich kinetic model well expressed E110 adsorption onto SMZ-CPC. Most of the dye removal takes place in less than 5 min and the maximum adsorption capacity is 5.06 mg/g. The results of this study show that zeolite modified with cationic surfactant is an effective adsorbent for removal anionic dyes from an aqueous solution.

Optimizing the green synthesis of antibacterial TiO2 - anatase phase nanoparticles derived from spinach leaf extract

Titanium dioxide nanoparticles, renowned for their abundance, non-toxicity, and stability, have emerged as indispensable components in various fields such as air purification, healthcare, and industrial processes. Their applications as photocatalysts and antibacterial agents are particularly prominent. The synthesis methods significantly influence the properties and subsequent applications of these nanoparticles. While several techniques exist, the biological approach using plant extracts offers advantages such as simplicity, biocompatibility, and cost-effectiveness. This study focused on the green synthesis of titanium dioxide nanoparticles utilizing spinach leaf extract. Within the scope of this investigation, the green synthesis of titanium dioxide nanoparticles through spinach leaf extract were synthesized and optimized, followed by a comprehensive examination of their morphological, structural, and chemical attributes with UV-visible spectroscopy, FTIR spectroscopy, XRD, FESEM, and EDX. The minimum inhibitory concentration (MIC) against E. coli and S. aureus was determined to evaluate their antibacterial potential. Optimal synthesis conditions were identified at 50 °C, using a 1/30 concentration and 20 ml of spinach leaf extract. Spherical anatase nanoparticles, ranging from 10 to 40 nm, were produced under these conditions. The change in the color of the extract, absorption at 247 nm, change and increase of the peak at 800 − 400 wavelengths, and the maximum intensity of X-ray diffraction at the angle of 25.367 with the crystal plane 101 were indications of the synthesis of these nanoparticles. Notably, the synthesized nanoparticles exhibited antibacterial activity with MIC values of 0.5 mg/ml against E. coli and 2 mg/ml against S. aureus. This research presents a novel, eco-friendly approach to synthesizing titanium dioxide nanoparticles with promising antibacterial properties.

Nucleic acid binding affinity and antioxidant activity of N-m-Tolyl-4-Chlorophenoxyacetohydroxamicacid.

Hydroxamic acids represent a group of weak organic acids, both naturally occurring and synthetically derived, characterized by the general formula RC(= O)N(R'OH). In this study, we investigated the binding behavior of N-m-tolyl-4-chlorophenoxyaceto hydroxamic acid with calf thymus DNA (ct-DNA) and torula yeast RNA (t-RNA) through a combination of techniques including UV-visible spectroscopy, fluorescence emission analysis, viscometry, and computational simulations using AutoDock4 software. Our findings reveal that the mode of binding between the compound and the nucleic acids is consistent with intercalation. Competitive binding experiments demonstrated that the complex competes effectively with ethidium bromide (EB) for binding to ct-DNA/t-RNA, displacing EB from its binding sites. Additionally, the introduction of the compound into the DNA-EB system resulted in a quenching of fluorescence emission peaks. Analysis of absorption spectra indicated a red shift and hypochromic shift when the compound interacted with DNA, further supporting the intercalative binding mode. The calculated binding constant (Kb) value for the compound is 6.62 × 104M-1 and 5.40 × 103M-1 indicating a strong interaction with ct-DNA and t-RNA respectively. We determined the Stern-Volmer constants for ct-DNA and t-RNA as 9.96 × 104M-1 and 8.13 × 105M-1, respectively. The binding free energy values for ct-DNA/t-RNA were calculated to be -3.741 × 107 and -5.425 × 108kcal/mol, respectively. Viscometric studies corroborated the UV results, showing a continuous increase in relative viscosity of ct-DNA/t-RNA solutions with the addition of the optimal hydroxamic acid concentration. Furthermore, we assessed the antioxidant activity of the compound using DPPH-radical scavenging and β-carotene linoleic acid assays. Gel electrophoresis results demonstrated the compound's remarkable efficacy in preventing DNA damage. Collectively, all experimental evidence supports the conclusion that N-m-tolyl-4-chlorophenoxyaceto hydroxamic acid binds to ct-DNA/t-RNA through an intercalative mechanism, which is consistent with our molecular docking simulations.

In-situ synthesis of iron nanoparticles using Tamarix articulata to reduce Cr (VI)

ABSTRACT This study introduces an eco-friendly method for synthesising iron nanoparticles (TA-FeNPs) using Tamarix articulata as a reducing and stabilising agent. Characterisation techniques, including UV-vis spectroscopy, X-ray diffraction, and scanning electron microscopy, revealed micrometre-sized, irregularly shaped nanoparticles with an amorphous structure. The Fe content was measured at 2.16%. The Cr (VI) removal efficiency dropped from 99.06% to 35.85% as pH increased from 2 to 5. Complete reduction was achieved at 25 mg/L concentration, pH 5.2, using 1 g/L over 60 minutes.

UV-curable aromatic polyurethanes from different sustainable resources: Protocatechuic and cinnamic acids

An innovative aromatic monomer, 3,4-dihydroxybenzyl cinnamate (CDHB), was synthesized from protocatechuic and cinnamic acids. These latter can be obtained from different sustainable resources, such as plastic waste or biomass, by biotechnology and/or chemistry routes. From CDHB, used as chain extender, and aromatic or aliphatic diisocyanates, various aromatic thermoplastic polyurethanes (TPU) with cinnamic pendant chains were carefully synthesized and characterized. Different techniques such as NMR, FTIR, TGA and DSC have been used. The main results show that the TPUs exhibited good phase segregation and thermal stability, due to the aromaticity of the chain extender. The pendant cinnamic chains acted as internal plasticizer with a reduction of the glass transition temperature (Tg). The cinnamic groups were also able to undergo a [2 + 2] cycloaddition under UV irradiation, leading to the crosslinking of PU with a strong evolution of the properties. This reaction was followed by UV–Vis spectroscopy. 80 % of cycloaddition was reached in 20 h, significantly increasing PU gel fraction, Tg, and thermal stability. This study highlights the potential to create modulable sustainable and aromatic PU macromolecular architectures that can be UV curable and display enhanced properties.

Assessment of Bryophyllum pinnatum mediated Ag and ZnO nanoparticles as efficient antimicrobial and cytotoxic agent.

Bryophyllum pinnatum is used to cure infections worldwide. Although the flavonoids of this plant are well known, it is still unknown how much of the plant's Ag and ZnO nanoparticles are beneficial. In the current research work, silver and zinc oxide nanoparticles were prepared using Bryophyllum pinnatum extract. The synthesized particles were characterized by UV-visible spectroscopy, SEM, EDS, XRD and FTIR. Synthesized particles were subjected to evaluation of their bactericidal and antifungal activity at various doses. Uv vis spectra at 400nm corresponding to AgNPs confirmed their synthesis. Strong peaks in the EDS spectra of Ag and ZnO indicate the purity of the sample. The scanning electron microscopic images of ZnONPs showed a size of about 60nm ± 3nm, which demonstrated the presence of triangular-shaped ZnO nanoparticles. Green synthesized nanoparticles showed bactericidal activity against both Gram-positive (Micrococcus luteus, Staphylococcus aureus, Bacillus subtilis) and Gram-negative (Agrobacterium tumifaciens, Salmonella setubal, Enterobacter aerogenes) strains. AgNPs proved to be more effective against Gram-negative bacterial strains compared to Gram-positive owing to MIC values (10 ppm and 20 ppm respectively). Whereas, ZnONPs were found more effective against Gram-positive bacteria with lower MIC values (10 ppm) as compared to Gram-negative ones (20 ppm). Also, the synthesized nanoparticles exhibited moderate dose-dependent antifungal activity against tested fungal strains ranging from 10 to 70%. Cytotoxicity of nanoparticles was found significant using Brine shrimp's lethality assay with IC50 values of 4.09 ppm for AgNPs, 13.72 ppm for ZnONPs, and 24.83 ppm for plant extract. Conclusively, Ag and ZnO nanoparticles were more effective than plant extract and AgNPs had higher activities than those of ZnONPs. Further research is warranted to explore the precise mechanism of action and the potential applications of these nanoparticles in the medical field.

Orange peel-mediated synthesis of silver nanoparticles with antioxidant and antitumor activities

Orange (Citrus sinensis L.) is a common fruit crop widely distributed worldwide with the peel of its fruits representing about 50% of fruit mass. In the current study, orange peel was employed to mediate the synthesis of silver nanoparticles (AgNPs) in a low-cost green approach. Aqueous extracts of suitably-processed peel were prepared using different extraction methods; and their phytochemical profile was identified. Based on phytochemical screening, amount of main phytochemicals, free radical-scavenging ability, reducing power and antioxidant activity, the peel extract prepared by boiling seemed to be the most promising. Thus, major compounds of this extract were identified by gas chromatography-mass spectrometry. Potency of the peel extract to mediate the synthesis of AgNPs was then monitored by visual observation, UV-visible spectroscopy, energy dispersive X-ray analysis, transmission electron microscopy and zetametry. Color change of the reaction mixture to brown and absorption peak at 450 nm indicated AgNPs formation. Characterization of AgNPs revealed spherical shape, size of 30–40 nm, zeta potential of -18.2 mV and yield conversion of 82%. The as-synthesized AgNPs had antioxidant capacity (free radical-scavenging ability, reducing power and antioxidant activity) lower than that of the orange peel extract. However, these biogenic AgNPs had antitumor activity (IC50 of 16 ppm against HCT-116 and 1.6 ppm against HepG2 cell lines) much higher than the peel extract that was completely non-toxic to the considered cell lines.

Comprehensive characterization of natural polysaccharide-based hydrogels with gradient structure in concentration and stiffness

Gradient hydrogels are functionally graded biomaterials that over the last decades have garnered significant attention as valuable materials for tissue repair and regeneration. This study elucidates key factors crucially determining the character or pattern of a buoyancy-driven gradient in agarose hydrogels and also provides fundamental information regarding the complex interpretation of the formed gradient hydrogels obtained by the different characterization techniques, including rheology, UV-Vis spectroscopy, FCS, AFM, SEM. The employed techniques were successfully optimized to enhance the understanding of the gradient properties of these hydrogels. Demonstrated results showed that the agarose concentration gradient could be successfully controlled and tailored, which offers a valuable contribution to the design of gradient hydrogel. Moreover, a novel method for determining the average agarose concentration along the gradient axis is presented, improving the precision of gradient characterization. The integration of these approaches significantly enhances the comprehension of the internal structure and properties of gradient materials, contributing to advancements in their understanding and application.

Elucidation of DNA binding properties of transition metal ion complexes of curcumin: An In Vitro study

Introduction: The present work aims to synthesize, characterize, and DNA binding properties of copper, nickel, zinc, and iron complexes of a well-known polyphenol drug curcumin. The metal ion complexes of curcumin's synthesized transition metal ion complexes were characterized by UV-vis spectroscopy and FTIR. Method: The complexation of curcumin with transition metal ion complexes changes the color of the curcumin based on the metal incorporated. Moreover, the shift in the absorption maxima of curcumin metal ion complexes may confirm the formation of coordination complexes. Then, FTIR results indicated that the coordination of curcumin with metal ions in the ketone group of curcumin confirms the formation of 1:2 (M: L) complexes. Results: Then, we evaluated the DNA binding properties of synthesized metal ion complexes of curcumin using electronic absorption spectra and agarose gel electrophoresis. The results indicated that the curcumin zinc complex exhibited less DNA binding constant among the four metal ion complexes than all the other compounds tested, confirming its weak interaction. Conclusion: Moreover, all the compounds degrade plasmid DNA, confirming their DNA cleavage activity. From our findings, these compounds will pave the way for developing new anticancer drugs with less toxicity.

Watermelon Derived Urease Immobilized Gold Nanoparticles-Graphene Oxide Transducer for Direct Detection of Urea in Milk Samples.

Urea contamination in milk poses significant health risks, including kidney failure, urinary tract obstruction, fluid loss, shock, and gastrointestinal bleeding. This highlights the need for sensitive, rapid, and reliable methods to detect traces amount of urea in milk. In this study, we designed an electrochemical transducer for urea detection by utilizing purified watermelon urease (Urs), gold nanoparticles (AuNPs), and graphene oxide (GO). The nanomaterials and biosensor probe were characterized using UV-vis spectroscopy, XPS, TEM, XRD, FTIR, AFM, CV, EIS, and DPV. The engineered probe (GCE/AuNPs/GO/Urs) demonstrated a broad linear detection range of 5 to 90 mg/dL and a low limit of detection (LOD) of 0.037 (±0.012) mg/dL (RSD < 3.7%). The biosensor was tested for potential interferents that may be present in adulterated milk and an exceptionally low coefficient of selectivity (ksel <0.1) was obtained. Evaluation of milk samples from a local dairy farm showed good recovery rates from 93.13% to. 98.79% (RSD < 4.28%, n = 3), indicating reliable detection capabilities. Stability tests confirmed the sensor's reproducibility and consistent performance. Additionally, a comparison study of the system was carried out using the purified watermelon urease and the commercially available urease. Herein, the results obtained using the sensor probe was finally validated with the gold standard method.

Gamma rays impact on 2D-MoS2 in water solution.

Two-dimensional transition metal dichalcogenides, particularly MoS2, are interesting materials for many applications in aerospace research, radiation therapy and bioscience more in general. Since in many of these applications MoS2-based nanomaterials can be placed in an aqueous environment while exposed to ionizing radiation, both experimental and theoretical studies of their behaviour under these conditions is particularly interesting. Here, we study the effects of tiny imparted doses of 511keV photons to MoS2 nanoflakes in water solution. To the best of our knowledge, this is the first study in which ionizing radiation on 2D-MoS2 occurs in water. Interestingly, we find that, in addition to the direct interaction between high-energy photons and nanoflakes, reactive chemical species, generated by γ-photons induced radiolysis of water, come into play a relevant role. A radiation transport Monte Carlo simulation allowed determining the elements driving the morphological and spectroscopical changes of 2D-MoS2, experimentally monitored by SEM microscopy, DLS, Raman and UV-vis spectroscopy, AFM, and X-ray photoelectron techniques. Our study demonstrates that radiolysis products affect the Molybdenum oxidation state, which is massively changed from the stable + 4 and + 6 states into the rarer and more unstable + 5. These findings will be relevant for radiation-based therapies and diagnostics in patients that are assuming drugs or contrast agents containing 2D-MoS2 and for aerospace biomedical applications of 2DMs investigating their actions into living organisms on space station or satellites.

Study of nonlinear optical properties of ZnCo2O4/GQD nanocomposite and their correlation with microstructure

In this study, ZnCo2O4/Graphene quantum dots (ZCO/GQDs) nanocomposite was fabricated by carbonization and hydrothermal methods in four volume ratios (40.0 ml/0.0, 37.5 ml/2.5 ml, 35.0 ml/5.0 ml, and 32.5 ml /7.5 ml) of ZCO/GQD where the total volume was fixed at 40 ml. To characterize the structural, morphological, and optical properties of the nanocomposites, x-ray diffraction, scanning electron microscopy, energy dispersive x-ray, UV-visible spectrometry, and Z-scan analysis were conducted. The variance and Williamson-Smallman methods were applied to calculate the microstructure features. The results illustrate that the crystallite size and strain are minimum while the dislocation density has a maximum value for 37.5 ml/2.5 ml of volume ratio. Band gap and nonlinear optical coefficients were obtained by Tauc and Z-scan techniques and the results show they are maximum in this ratio. These results confirm a correlation between microstructure and optical properties. Such a correlation can be applied to improve the optoelectronic applications of the nanocomposite.