Ultraviolet-visible Spectroscopy Research Articles

In vivo photoreceptor base editing ameliorates rhodopsin-E150K autosomal-recessive retinitis pigmentosa in mice

Rhodopsin, the prototypical class-A G-protein coupled receptor, is a highly sensitive receptor for light that enables phototransduction in rod photoreceptors. Rhodopsin plays not only a sensory role but also a structural role as a major component of the rod outer segment disc, comprising over 90% of the protein content of the disc membrane. Mutations in RHO which lead to structural or functional abnormalities, including the autosomal recessive E150K mutation, result in rod dysfunction and death. Therefore, correction of deleterious rhodopsin mutations could rescue inherited retinal degeneration, as demonstrated for other visual genes such as RPE65 and PDE6B. In this study, we describe a CRISPR/Cas9 adenine base editing strategy to correct the E150K mutation and demonstrate precise in vivo editing in a Rho -E150K mouse model of autosomal recessive retinitis pigmentosa (RP). Using ultraviolet-visible spectroscopy, mass spectrometry, and the G-protein activation assay, we characterized wild-type rhodopsin and rhodopsin variants containing bystander base edits. Subretinal injection of dual-adeno-associated viruses delivering our base editing strategy yielded up to 44% Rho correction in homozygous Rho -E150K mice. Injection at postnatal day 15, but not later time points, restored rhodopsin expression, partially rescued retinal function, and partially preserved retinal structure. These findings demonstrate that in vivo base editing can restore the function of mutated structural and functional proteins in animal models of disease, including rhodopsin-associated RP and suggest that the timing of gene-editing is a crucial determinant of successful treatment outcomes for degenerative genetic diseases.

Enhancement of the Photoluminescent Intensity of YVO4: Er, Yb UCNPs Using a Simple Coprecipitation Synthesis Method.

Yttrium vanadate (YVO4) is a non-toxic ceramic matrix that, when doped with lanthanides, can be used as a photoluminescent biosensor. In this study, we meticulously synthesized upconversion nanoparticles (UCNPs) of YVO4 via chemical coprecipitation, using Er3+ and Yb3+ ions for codoping. The light emission achieved through upconversion mechanisms enables the excitation of nanoparticles with infrared light rather than ultraviolet light, enhancing the potential of current bioimaging techniques. The light emission intensity of our YVO4: Er, Yb UCNPs, a key factor in their effectiveness, depended on various easily adjustable factors during the synthesis, such as the dopant concentration, the heat treatment, and the cleaning process. The UCNPs were characterized using a range of advanced techniques, including X-ray diffraction (XRD) and Rietveld refinements, as well as Raman, photoluminescence (PL), and ultraviolet-visible (UV-vis) spectroscopies, and high-resolution transmission electron microscopy (HRTEM). We found the most convenient stoichiometry to obtain the YVO4: Er, Yb UCNPs and showed that a rigorous thermal treatment was necessary to achieve light emission through upconversion mechanisms. We also discovered that some porosity characteristics can be promoted in the YVO4: Er, Yb UCNPs during the cleaning process, depending on the solvent employed. The porosity and morphology of the nanoparticles could be predicted using the microstrain values obtained from the refinement of the crystalline structures. All these meticulous steps in our research have enabled us to develop an efficient synthesis pathway to produce YVO4: Er, Yb UCNPs with high photoluminescent intensity.

DNA binding, and apoptosis-inducing activities of a β-ionone-derived ester in human myeloid leukemia cells: multispectral and molecular dynamic simulation analyses.

β-Ionone is the end-ring counterpart of β-carotenoids, which are widely found in fruits and vegetables. Recent studies have illustrated the antimetastatic, anti-proliferative, and apoptosis-inducing activities of β-ionone both in vitro and in vivo. We aimed to explore the anti-cancer potency of β-Ionone-derived ester, (E)-4-(2,6,6-trimethylcyclohex-1-enyl) but-3-en-2-ylpyrazine-2-carboxylate (4-TM.P). The cytotoxic effects of the compound on K562 cells were evaluated by MTT assay. The mechanisms of apoptosis induction were investigated by acridine orange/ethidium bromide (AO/EtBr) double staining, cell cycle analysis, and Annexin V/PI staining. Furthermore, the 4-TM.P-DNA interactions have been thoroughly elucidated by various methods, such as ultraviolet-visible spectroscopy, fluorescence assays, viscosity measurements, molecular docking, and dynamic simulation. The MTT cytotoxicity assay revealed that the growth of K562 cells was inhibited by treatment with β-ionone-derived ester, with an IC50 of 25 ± 5.0µM at 72h. Morphological studies revealed the occurrence of apoptosis in treated cells, and G0/G1 cell cycle arrest was observed after treatment of the cells with the IC50 value of the compound. Analyses of multi-spectroscopy and viscosity assays revealed that 4-TM.P binds to DNA in the minor groove mode, which was supported by molecular docking studies. The dynamic stability of the complex was also confirmed using molecular dynamic simulation analyses.

Size dependent properties of Gd3+-free versus Gd3+-doped carbon dots for bioimaging application.

Gd3+- free carbon dots (CDs) were synthesized by one-step solvothermal method using urea, citric acid and 3-(trifluoromethyl)aniline as precursors. Additionally, Gd3+-doped CDs were prepared by incorporating gadolinium chloride (Gd3+ ions) into the synthesis. Size selection of the purified CDs was achieved through filter membranes ranging from 3kDa to 100kDa. The chemical composition and optical properties of the obtained samples were characterized by Energy dispersive X-ray (EDX), Fourier-transform infrared spectroscopy (FTIR), Dynamic Light Scattering (DLS), proton relaxation time measurements, Ultraviolet-visible (UV-vis) and fluorescence spectroscopies. A comparative analysis revealed a strong size-dependent behavior in the optical properties of both Gd3+-doped and Gd3+-free CDs. Furthermore, in vitro tests confirmed the non-cytotoxicity of Gd3+-doped CDs, indicating their potential applicability in biomedicine for magnetic resonance imaging (MRI) and red fluorescence-based cell and tissue imaging.

Development of novel reduced graphene oxide/metalloporphyrin nanocomposite with photocatalytic and antimicrobial activity for potential wastewater treatment and medical applications.

This research investigates a novel nanocomposite material composed of reduced graphene oxide (rGO) and nickel-5,15-bisdodecylporphyrin (Ni-BDP) nanoparticles for the effective removal of methyl orange (MO), a harmful synthetic dye, from water. The structure and composition of the synthesized rGO/Ni-BDP nanocomposite were characterized using high-resolution transmission electron microscopy (HR-TEM), Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, and ultraviolet-visible (UV-Vis) spectroscopy. The study demonstrates the material's efficacy as both a catalyst and adsorbent for MO removal. Optimal performance was observed at pH 3.0, where the positively charged nanocomposite surface facilitated strong interactions with negatively charged MO molecules, leading to enhanced photocatalytic activity. Under these conditions, 0.01g of the nanocomposite achieved an impressive 86.2% MO removal efficiency. Furthermore, the study explored the reusability of the rGO/Ni-BDP nanocomposite in repeated cycles of photocatalytic MO degradation under visible light irradiation. While exhibiting some decrease in efficiency over five cycles, the nanocomposite maintained a respectable degradation rate even after multiple uses. Finally, the antimicrobial properties of the nanocomposite were evaluated against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria exhibiting a zone of inhibition measuring 23mm and 26, respectively. The minimum inhibitory concentration (MIC) values of 2.50µg/ml and 1.25µg/ml for Escherichia coli and Staphylococcus aureus, respectively. The results revealed significant antibacterial activity, demonstrating the broad-spectrum efficacy of the rGO/Ni-BDP nanocomposite. This research underscores the potential of the rGO/Ni-BDP nanocomposite as a versatile material for environmental remediation and antibacterial applications.

Exploring Pt-Impregnated CdS/TiO2 Heterostructures for CO2 Photoreduction

This work focuses on the production of methane through the photocatalytic reduction of carbon dioxide using Pt-doped CdS/TiO2 heterostructures. The photocatalysts were prepared using P25 commercial titania and CdS synthesized through a solvothermal methodology, followed by the impregnation of Pt onto the surface to enhance the physicochemical properties of the resulting photocatalysts. The pure and heterostructure-based materials were characterized using X-ray diffraction (XRD), inductively coupled plasma optical emission spectroscopy (ICP-OES), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy (UV-Vis), ultraviolet photoelectron spectroscopy (UPS), and photoluminescence spectroscopy (PL). The obtained results show the successful synthesis of the heterostructure impregnated with Pt. Moreover, the observed key role of CdS and Pt nanoparticles in the final semiconductor is to reduce the electron-hole pair recombination rate by acting as an electron sink, which slows down the recombination process and increases the photocatalyst efficiency. Thus, Pt-doped CdS/TiO2 heterostructures with the best observed composition presents better catalytic activity than P25 titania with methane production values being 460 and 397 µmol CH4/g·h, respectively.

Nanotechnology-enhanced Phytonutraceuticals: Innovations in Characterization, Formulation, and Therapeutic Applications

Nanotechnology refers to the branch of science and engineering devoted to designing, producing, and using structures, devices, and systems by manipulating atoms and molecules at nano-scale, having one or more dimensions of the order of 100 nanometres (100 millionth of a millimetre) or less. Nanotechnology is the exploitation of the unique properties of materials at the nanoscale. Nanotechnology has gained popularity in several industries, as it offers better built and smarter products. The ability to manipulate structures at the atomic scale allows for the creation of nanomaterials. Nanomaterials have unique optical, electrical and/or magnetic properties at the nanoscale, and these can be used in the fields of electronics and medicine, amongst other scenarios. Nanomaterials are unique as they provide a large surface area to volume ratio. Unlike other large-scaled engineered objects and systems, nanomaterials are governed by the laws of quantum mechanics instead of the classical laws of physics and chemistry. Nanotechnology is the engineering of useful objects and functional systems at the molecular or atomic scale. Nano-formulations are widely used for phyto-nutraceuticals and drug delivery systems. These substances are generally having low solubility, leading to their poor absorption and bioavailability in the human body. In this regard, one of the most important applications of nanotechnology in food sector has been the formulation of novel neutraceutical compounds with improved properties viz., enhanced solubility, stability, bioavailability and efficacy. This is achieved by encapsulation of neutraceutical by nanoparticles, which modifies their pharmacokinetics (PK) and biodistribution (BD). Nano-formulations widely used for the purpose are nanoliposomes, nanoemulsions, nanoparticles, nanofibres. The particles are characterized by scanning probe microscope (SPM), Ultraviolet-visible spectroscopy (UV-Vis spectrophotometer, SEM, TEM, Dynamic light scattering (DLS).

Green Hydrothermal Synthesis of Gallic Acid Carbon Dots: Characterization and Cytotoxic Effects on Colorectal Cancer Cell Line.

Colorectal cancer remains a leading cause of cancer-related deaths worldwide, necessitating the development of novel therapeutic approaches. Carbon dots (CDs) have emerged as promising nanoparticles for biomedical applications due to their unique properties. Gallic acid (GA), a known anticancer agent, is effective against various tumor types. This study explores the potential of gallic acid-derived carbon dots (GA-CDs) as an innovative anticancer agent against HCT-116 colorectal cancer cells, focusing on apoptosis signaling pathways. GA-CDs were synthesized using a one-pot hydrothermal method. Characterization was conducted using transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, and ultraviolet-visible (UV-Vis) absorption spectroscopy. The cytotoxicity of GA and GA-CDs on HCT-116 cells was evaluated using the MTT assay at various concentrations over 24 and 48 hours. Cellular uptake was assessed via fluorescence microscopy, and apoptosis was analyzed using acridine orange/propidium iodide (AO/PI) staining. Total RNA extraction followed by complementary DNA (cDNA) synthesis via RT-PCR was performed, and real time-PCR (Q-PCR) was conducted to examine the expression of apoptosis-related genes Caspase-3, Bax, and Bcl-2. Characterization confirmed the successful synthesis of spherical GA-CDs. GA-CDs exhibited dose- and time-dependent cytotoxicity, with IC50 values of 88.55 µg/mL for GA-CDs and 192.2 µg/mL for GA after 24 hours. Fluorescence microscopy confirmed the efficient uptake of GA-CDs by HCT-116 cells. AO/PI staining showed a significant increase in apoptotic cell numbers after treatment with GA-CDs. Q-PCR analysis revealed overexpression of Caspase-3 and Bax genes in GA-CD-treated cells, though no significant changes were observed in the expression of Bcl-2 or the Bax/Bcl-2 ratio. GA-CDs demonstrated potent anticancer properties by inducing apoptosis and reducing cell viability in HCT-116 cells. These findings suggest the potential of GA-CDs as a novel therapeutic agent for colorectal cancer treatment, warranting further investigation into their mechanism of action and in vivo efficacy.

The Effect of Hydrodynamic Cavitation on the Structural and Functional Properties of Soy Protein Isolate–Lignan/Stilbene Polyphenol Conjugates

In this study, hydrodynamic cavitation technology was utilized to prepare conjugates of soy protein isolate (SPI) with polyphenols, including resveratrol (RA) and polydatin (PD) from the stilbene category, as well as arctiin (AC) and magnolol (MN) from the lignan category. To investigate the effects of hydrodynamic cavitation treatment on the interactions between SPI and these polyphenols, the polyphenol binding capacity with SPI was measured and the changes in the exposed sulfhydryl and free amino contents were analyzed. Various methods, including ultraviolet–visible spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy, and circular dichroism spectroscopy, were also used to characterize the structural properties of the SPI–polyphenol conjugates. The results showed that compared to untreated SPI, SPI treated with hydrodynamic cavitation exposed more active groups, facilitating a greater binding capacity with the polyphenols. After the hydrodynamic cavitation treatment, the ultraviolet–visible absorption of the SPI–polyphenol conjugates increased while the fluorescence intensity decreased. Additionally, the content of exposed sulfhydryl and free amino groups declined, and changes in the secondary structure were observed, characterized by an increase in the α-helix and random coil content accompanied by a decrease in the β-sheet and β-turn content. Furthermore, the SPI–polyphenol conjugates treated with hydrodynamic cavitation demonstrated improved emulsifying characteristics and antioxidant activity. As a result, hydrodynamic cavitation could be identified as an innovative technique for the preparation of protein–phenolic conjugates.

DNAR-01. THERAPEUTIC APPLICATIONS OF MESENCHYMAL STEM CELL LOADED WITH GOLD NANOPARTICLES FOR REGENERATIVE MEDICINE

Abstract In the present study, the various concentrations of AuNP (1.25, 2.5, 5, 10 ppm) were prepared to investigate the biocompatibility, biological performances and cell uptake efficiency via Wharton’s jelly mesenchymal stem cells and rat model. The pure AuNP, AuNP combined with Col (AuNP-Col) and FITC conjugated AuNP-Col (AuNP-Col-FITC) were characterized by Ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR) and Dynamic Light Scattering (DLS) assays. For in vitro examinations, we explored whether the Wharton’s jelly MSCs had better viability, higher CXCR4 expression, greater migration distance and lower apoptotic-related proteins expression with AuNP 1.25 and 2.5 ppm treatments. Furthermore, we considered whether the treatments of 1.25 and 2.5 ppm AuNP could induce the CXCR4 knocked down Wharton’s jelly MSCs to express CXCR4 and reduce the expression level of apoptotic proteins. We also treated the Wharton’s jelly MSCs with AuNP-Col to investigate the intracellular uptake mechanisms. The evidence demonstrated the cells uptake AuNP-Col through clathrin-mediated endocytosis and the vacuolar-type H+-ATPase pathway with good stability inside the cells to avoid lysosomal degradation as well as better uptake efficiency. Additionally, the results from in vivo examinations elucidated the 2.5 ppm of AuNP attenuated foreign body responses and had better retention efficacy with tissue integrity in animal model. In conclusion, the evidence demonstrates that AuNP shows promise as a biosafe nanodrug delivery system for development of regenerative medicine coupled with Wharton’s jelly MSCs.

Isolation of Flavonoid Compounds Derived from Buni Leaves (Antidesma bunius (L) Spreng.)

The flavonoid compounds from the leaves of buni (A. bunius (L) Spreng.) have been isolated through a process of maceration utilizing methanol as the solvent. The concentrated methanol extract was combined with ethyl acetate. The concentrated ethyl acetate extract was subsequently dissolved in methanol and subjected to partition extraction using n-hexane. The concentrated methanol extract was acidified with 6% HCl, followed by partition extraction using chloroform. The concentrated chloroform extract was isolated using column chromatography, employing an eluent mixture of n-hexane and ethyl acetate in the following ratios: 90:10, 80:20, 70:30, and 60:40 (v/v). The compounds underwent purification via TLC preparative, resulting in a tawny paste with a mass of 30 mg and an Rf value of 0.31. The compound underwent additional identification through the application of Ultraviolet Visible (UV-Vis) spectroscopy, Fourier Transform-Infrared Spectroscopy (FT-IR), and Proton Nuclear Magnetic Resonance Spectroscopy (1H-NMR), leading to the conclusion that the flavonoid in question is isoflavone.

Spectroscopic and Molecular Docking Studies on the Influence of Inulin on the Interaction of Sophoricoside with Whey Protein Concentrate

The influence of inulin on the interaction of sophoricoside (Sop) with whey protein concentrate (WPC) was investigated using various spectroscopic methods, including fluorescence spectroscopy (intrinsic fluorescence, synchronous fluorescence, and three-dimensional fluorescence), ultraviolet-visible (UV–Vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and molecular docking. Sop was found to quench the intrinsic fluorescence of WPC by a static mechanism, both with and without the addition of inulin, and to enhance the antioxidant capacity of the protein. The addition of inulin slightly increased the binding distance between WPC and Sop, while reducing the number of binding sites from two to one. Non-covalent interactions, predominantly van der Waals forces and hydrogen bonding, were maintained between Sop and the protein. Synchronous fluorescence spectroscopy revealed that Sop prevents the exposure of hydrophobic groups on tryptophan residues, leading to increased surface hydrophilicity of the WPC complex. This aligns with the decreased protein surface hydrophobicity measured by 8-Anilino-1-naphthalenesulfonic acid (ANS) binding assays. With inulin, the overall hydrophobicity of the protein was lower than in the system without inulin, suggesting that both inulin and Sop improve the solubility of WPC. Three-dimensional fluorescence spectral analysis showed a reduction in fluorescence intensity and a red shift in the presence of both Sop and inulin. FTIR spectroscopy indicated a slight increase in the secondary structure ordering of WPC following the addition of both Sop and inulin, suggesting structural stabilization under heating conditions. Molecular docking highlighted the potential for hydrogen bond formation between Sop and WPC.

High-Performance Ga2O3 Solar-Blind Photodetector Based on Thermal Oxidized Ga Buffer-Layer.

High-performance Ga2O3 solar-blind photodetectors are critical for applications due to their selective solar-blind ultraviolet sensitivity. The quality of the Ga2O3 film has a significant impact on the performance of photodetectors. This study presents an innovative approach to enhancing the quality of Ga2O3 films through the introduction of a naturally graded buffer layer, which is formed by the oxidation of a metallic Ga film and significantly improves interface stability by accommodating lattice mismatches and reducing defects. The structural and compositional characteristics of Ga2O3 films were comprehensively analyzed using UV-vis (ultraviolet-visible) spectroscopy, AFM (Atomic Force Microscope), PL (Photoluminescence Spectroscopy), TEM (Transmission Electron Microscope), and XPS (X-ray Photoelectron Spectroscopy). The photodetectors fabricated from these films demonstrate responsivity of 99.8 mA/W and a solar-blind UV/UV ratio of 1.17 × 103, with significant improvement compared to direct deposited films. This research highlights the potential of natural buffering layers to advance the performance of Ga2O3-based solar-blind UV detectors.

Gamma-ray shielding effectiveness, optical, mechanical, dielectric properties of nanofiller-reinforced PVA/PVP polymeric blend nanocomposites

The aqueous solution cast method was used to create the biodegradable polymer nanocomposite (PNC) films from a blend of poly (vinyl alcohol) PVA and poly (vinyl pyrrolidone) PVP (70/30 wt %) and Fe2O3 nanoparticles (NPs). These PNC films were characterized using X-ray diffraction, scanning electron microscopy SEM, Fourier transform infrared spectroscopy FTIR, and ultraviolet-visible spectroscopy. XRD and FTIR results indicate that Fe+ 3 NPs interact with the host polymer. Optical, electrical, mechanical, and radiation shielding measurements were performed on the PNC films. From the optical measurements, the indirect optical band gap drops from 4.86 eV for the pure blend to 4.26 eV at the greatest NPs concentration. Optical limiting characterization shows that the output power of He-Ne and solid-state green laser beams is reduced from 22.98 to 3.6 mW and 6.59 to 1.4 mW, respectively, when the Fe2O3 NPs content in the blend matrix is increased to 6 wt %. The NGCal software was utilized to calculate nuclear radiation shielding properties. The findings demonstrated that when the concentration of Fe2O3 rose, the PNC films half-value layer and mean free path decreased. Mechanical measurements demonstrate that increasing the Fe2O3 content significantly improves nanocomposite films’ yield and tensile strength. Tensile strength is measured at 27.03 MPa for the composite film containing 6 wt % Fe2O3, which is significantly higher than the 8.66 MPa of the pure (PVA-PVP) film. Compared to the other samples under examination, the 6 wt % Fe2O3 sample yielded the best results (based on the analyzed optical, electrical, mechanical, and radiation shielding properties).

High-Strength, Self-Healing Copolymers of Acrylamide and Acrylic Acid with Co(II), Ni(II), and Cu(II) Complexes of 4′-Phenyl-2,2′:6′,2″-terpyridine: Preparation, Structure, Properties, and Autonomous and pH-Triggered Healing

The utilization of self-healing polymers is a promising way of solving problems associated with the wear and tear of polymer products, such as those caused by mechanical stress or environmental factors. In this study, a series of novel self-healing, high-strength copolymers of acrylamide, acrylic acid, and novel acrylic complexes of 4′-phenyl-2,2′:6′,2″-terpyridine [Co(II), Ni(II), and Cu(II)] was prepared. A systematic study of the composition and properties of the obtained polymers was carried out using a variety of physicochemical techniques (elemental analysis, gel permeation chromatography (GPC), attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FT-IR), ultraviolet-visible spectroscopy (UV-vis), small-angle X-ray scattering (SAXS), wide-angle X-ray scattering (WAXS), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), confocal laser scanning microscopy (CLSM), and tensile testing). All metallopolymer samples exhibit autonomous intrinsic healing along with maintaining high tensile strength values (for some samples, the initial tensile strength exceeded 100 MPa). The best values of healing efficiency are possessed by metallopolymers with a nickel complex (up to 83%), which is most likely due to the highest lability of the metal–heteroatom coordination bonds. The example of this system shows the ability to re-heal with negligible deterioration of the mechanical properties. The possibility of tuning the mechanical properties of self-healing films through the use of different metal ions has been demonstrated.

Enhanced performance of Mg and La co-doped TiO2(98%)−ZrO2(2%) photoanode for dye-sensitized solar cells

Abstract This study explores the effects of magnesium (Mg) and lanthanum (La) doping on the performance of dye-sensitized solar cells (DSSCs) utilizing TiO2(98%)−ZrO2(2%) (TZ, TZM, and TZL) photoanodes. The photoanodes were fabricated using a spin-coating sol–gel method, followed by calcination at 400°C. The structural, morphological, crystallographic, and optical properties of the proposed photoanode composites were characterized by X-ray diffraction, transmission electron microscopy, and ultraviolet–visible spectroscopy. The crystallite sizes of the synthesized thin films varied from 21.16 to 59.04 nm for the TZ, TZM, and TZL compositions. The current–voltage measurements of DSSCs based on TZL8 photoanode, cobalt sulfide-doped graphene counter electrode, and N719 dye revealed the highest efficiency of nearly 5.052%. The assembled DSSCs exhibited an open-circuit voltage of 0.74 V, a short-circuit current density of 9.964 mA/cm2, and a fill factor of 0.685. The enhancement in open-circuit voltage and short-circuit current density could be attributed to the improved electronic and microstructures of the proposed photoanodes.

Low thickness effect on the properties of Mn-doped ZnO thin films synthesized by sol-gel spin coating technique

In this study, 7% manganese-doped zinc oxide (MZO) thin films with varying low thicknesses were synthesized using the spin coating method. The structural, optical, and morphological properties of MZO films with different film thickness, were systematically investigated. The crystallite structure, superficial morphology, and optical characteristics were analyzed using X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), and ultraviolet–visible spectroscopy (UV-Vis). Structural analysis confirmed that all films exhibit a hexagonal wurtzite phase with a pronounced peak along the c-axis, and slight variation in low thickness significantly affected the structural parameters. The surface morphology demonstrated good uniformity, characterized by rounded grain shapes in the plane, while surface roughness was found to be increased with increasing film thickness. Optical analysis revealed that as the number of coatings increased, both transmittance and band gap energy decreased, accompanied by a redshift in the absorption edge across all samples. This behavior is attributed to light scattering, as well as an increase in the refractive index and dielectric function with visible light energy, influenced by the number of layers and corresponding crystallite size.

Synthesis, Characterization, Density Functional Theory Study, Antibacterial Activity and Molecular Docking of Zeolitic Imidazolate Framework‐8

ABSTRACTIn this study, Zeolitic Imidazolate Framework‐8 (ZIF‐8) nanomaterials were synthesized using a co‐precipitation one‐pot method that uses ethanol, methanol, and water as solvents for the precursors (2‐methylimidazole and Zinc nitrate hexahydrate), resulting in yields of 66.77%, 73.14%, and 68.12%, respectively. The as‐synthesized ZIF‐8 nanomaterials were thoroughly characterized by X‐ray diffraction analysis, transmission electron microscopy, ultraviolet–visible spectroscopy, and Fourier‐transform infrared spectroscopy. The X‐ray diffraction analysis showed that the crystallite size of ethanol‐based ZIF‐8 (24.76 ± 1.67 nm) was smaller than those synthesized in water (26.92 ± 1.89 nm) and methanol (31.39 ± 1.03 nm). However, methanol‐based ZIF‐8 exhibited lower crystallinity (85.93%) than water‐based ZIF‐8 (91.48%) and ethanol‐based ZIF‐8 (92.71%). Zeta potential studies revealed that ethanol‐based ZIF‐8 had a larger surface charge (+37 mV) than water‐based ZIF‐8 (+35 mV) or methanol‐based ZIF‐8 (+24 mV). Transmission electron microscopy analysis confirmed particle sizes of 54.35 ± 2.11 nm for ethanol‐based ZIF‐8, 57.91 ± 2.26 nm for water‐based ZIF‐8, and 63.25 ± 4.12 nm for methanol‐based ZIF‐8. Thermogravimetric analysis indicated thermal stability up to 800 °C, with mass losses of 55.98% for ethanol‐ZIF‐8, 50.12% for water‐based ZIF‐8, and 65.36% for methanol‐based ZIF‐8 by 600 °C. In antibacterial studies, water‐based ZIF‐8 exhibited the largest zone of growth inhibition (17.30 ± 0.26 mm) against Escherichia coli compared to ethanol‐based ZIF‐8 (15.57 ± 0.32 mm) and methanol‐based ZIF‐8 (14.70 ± 0.20 mm). Pearson's correlation study revealed that zeta potential, crystallinity, and antibacterial activity are positively related. Furthermore, water‐based ZIF‐8, with a minimum inhibitory concentration of 50 μg/100 μL, confirmed evident cell membrane disruption. Molecular docking experiments revealed ZIF‐8's significant binding affinity for the E. coli protein 5AZC, supporting its robust antibacterial activity.

Photocatalytic Degradation of Four Organic Dyes Present in Water Using ZnO Nanoparticles Synthesized with Green Synthesis Using Ambrosia ambrosioides Leaf and Root Extract

Currently, several organic dyes found in wastewater cause severe contamination problems for flora, fauna, and people in direct contact with them. This research proposes an alternative for the degradation of polluting dyes using ZnO nanoparticles (NPs) synthesized by an ecological route using leaf and root extracts of Ambrosia ambrosioides as a reducing agent (with a weight/volume ratio = 4%). Scanning Electron Microscopy (SEM) was used to determine the morphology, showing an agglomeration of cluster-shaped NPs. Using Transmission Electron Microscopy (TEM), different sizes of NPs ranging from 5 to 56 nm were observed for both synthesized NPs. The composition and structure of the nanomaterial were analyzed by infrared spectroscopy (FT-IR) and X-ray diffraction (XRD), showing as a result that the NPs have a wurtzite-like crystalline structure with crystallite sizes around 32–37 nm for both samples. Additionally, the bandgap of the NPs was calculated using Ultraviolet Visible Spectroscopy (UV–Vis), determining values of 2.82 and 2.70 eV for the NPs synthesized with leaf and root, respectively. Finally, thermogravimetric analysis demonstrated that the nanoparticles contained an organic part after the green synthesis process, with high thermal stability for both samples. Photocatalytic analysis showed that these nanomaterials can degrade four dyes under UV irradiation, reaching 90% degradation for methylene blue (MB), methyl orange (MO) and Congo red (CR) at 60, 100 and 60 min, respectively, while for methyl red (MR) almost 90% degradation was achieved at 140 min of UV irradiation. These results demonstrate that it is effective to use Ambrosia ambrosioides root and leaf extracts as a reducing agent for the formation of ZnO NPs, also evidencing their favorable application in the photocatalytic degradation of these four organic dyes.

Maillard reaction-based conjugation of pea protein and prebiotic (polydextrose): optimization, characterization, and functional properties enhancement

There is a growing demand for plant-based protein ingredients with improved functionality for use in diverse food and nutraceutical applications. In line with this, the current study aimed to investigate the effect of plant protein-prebiotic (polydextrose) conjugation on the techno-functional properties (emulsification, solubility, fat absorption and foaming) of pea proteins through wet heating Maillard reaction. Pea protein (PeP) was conjugated with polydextrose by incubating the mixture at various process conditions (pea protein: polydextrose mass ratios, temperature, and time). Response surface methodology coupled with Box–Behnken design was used to optimize multiple responses, including conjugation efficiency (CE), emulsifying activity (EAI), and foaming capacity (FC). The pea protein conjugate (optimized value) showed improved solubility throughout a wide pH (2–10) range and higher emulsification activity than pea protein alone. The development of conjugates (PeC) was validated through ultraviolet–visible spectroscopy, FTIR, and o-Phthaldialdehyde (OPA) assay. Browning index, FT-IR spectra, thermal properties, and scanning electron microscopy (SEM) micrographs were analyzed for the conjugate (PeC) obtained at optimized values. The FTIR spectra of the conjugates showed new peaks at 3100–3480 cm−1 and 1,000–1,166 cm−1 indicating conjugation. The Maillard conjugation increased the proportion of β-turn, random coil, accompanied by a decrease in α-helix, and β-sheet. These conformational changes were associated to the improved techno-functional properties of the pea protein upon conjugation, offering potential applications in the formulation of plant-based foods and beverages.