UV Vis Spectra Research Articles

Biosynthesis of ZnO-NPs from mycoendophyte Alternaria alternata

Fungi-mediated biosynthesis of nanoparticles is a potentially beneficial strategy for large-scale production. In this study, ZnO-NPs were synthesized biogenically using a cell free broth from mycoendophyte Alternaria alternata inhabiting Piper cubeba as a reducer and stabilizer agent. ZnO-NPs appeared to be spherical in transmission electron microscopy, Histogram reveals the nanoparticle size between 20 and 60 nm, and FTIR experiments were employed to analyze the structure, shape, and physicochemical characteristics of the ZnO-NPs. The biosynthesized nanoparticles exhibited an absorption peak at 346 nm in the UV–visible spectrum, which corresponded to the plasmon resonance of ZnO-NPs. The X-ray diffraction spectra of the nanoparticles revealed the formation of crystal planes and hexagonal crystal geometry metal oxides of zinc. In experiments, biosynthesised ZnO-NPs were proven to be exhibit broad spectrum antimicrobial activity. Based on antimicrobial studies bacteria were found to be more susceptible when compare to fungi exhibiting antibacterial activity equal that of co-assayed standard (18–21 mm zone of inhibition). As a result, ZnO-NPs could be mass-produced sustainably, with the potential to be used in a range of biological processes.

Synthesis, crystal structures and urease inhibition of nickel(II), copper(II), zinc(II) and molybdenum(VI) complexes derived from N,n’-bis(4-bromosalicylidene)-1,3-propanediamine

Three new trinuclear complexes containing either nickel(II), copper(II) or zinc(II), [Ni3L2(NO3)2(CH3OH)2]·2CH3OH (1), [Cu3Br2L2] (2), [Zn3L2(NCS)2(CH3OH)2]·0.5CH3OH·0.5H2O (3), and a new dioxidomolybdenum(VI) complex, [MoO2L] (4), have been prepared from the bis-Schiff base N,N’-bis(4-bromosalicylidene)-1,3-propanediamine (H2L) with various metal salts in methanol. The complexes were characterized by elemental analysis, IR and UV–Vis spectra. Molecular structures were confirmed by single crystal X-ray diffraction experiments. The Ni ions in 1 adopt an octahedral coordination environment, bridged by phenolate oxygen and nitrate ligands. The Cu ions in 2 are square pyramidal and square planar, and the Zn ions in 3 are square pyramidal and octahedral. The metal atoms in 2 and 3 are bridged by phenolate oxygen donors. The Mo ion in 4 is octahedral. The Schiff base ligand coordinates to the metal atoms through two phenolate O and two imino N donors. Biological assays revealed that the nickel and copper complexes have effective urease inhibition.

D-π-A Carbzazole Based Reactive Cyano-Substituted C = C bond Probe for Selective and Sensitive Detection of Hydrazine in Aqueous Media.

This work established a newly designed and synthesized carbazole N-phenyl π-conjugated vinyl malononitrile (CPM) fluorescent sensor, which showed typical and remarkable redshift emission properties with different polarity index solvents. Investigative probe CPM is colorimetric and fluorimetric ultrafast and ultrasensitive detection of hazardous hydrazine in an aqueous medium. Furthermore, CPM showed colorimetric and fluorometric responses to interference tests with other amines and high selectivity for detecting hydrazine without interference with other amines in colorimetric and fluorimetric methods. This probe CPM for hydrazine was as low as the lower detection limit value of 2.21 × 10- 8 M. The probe CPM expects significant attention due to its simplicity and cost-effectiveness in detecting hazardous hydrazine. UV-vis, PL, NMR, and MS spectra confirmed the mechanism of probe CPM detection of hazardous hydrazine. However, making a piece test kit attractive for practical hydrazine vapor leak-detection applications is easy. This study can be applied to many pipeline gas transmission industries and transportation facility sectors.

Green biosynthesis of Ag2O nanoparticles by aqueous leaves extract of Thymus capitatus (Lamiaceae): effect of silver nitrate weight in optical and their biological activity

In this study, green synthesis of silver oxide nanoparticles (Ag2O NPs) was achieved by bio-reduction of AgNO3 using Thymus Capitatus leaves extract. The effect of silver precursor contraction (0.1–1 g, AgNO3) was studied. X-ray diffraction confirmed the crystalline nature of Ag/Ag2O NPs with a crystallite size range from 18 to 24 nm. SEM showed that the green synthesizing silver oxide nanoparticles having in general as cubical shape. The obtained Ag2O NPs exhibit absorption at 273 nm with a direct bandgap ranging from 3.87 to 4.02 eV and an indirect bandgap of 2.99–3.44 eV, according to Uv-visible spectra. FTIR analysis exhibit a two weak peak at 517 and 458 cm−1 attributed to silver oxide-NPs vibration, confirming the nanoparticles formation. Among the examined extracts, Ag2O NPs with 1 g weight of AgNO3 showed the highest antioxidant activity with value of 3.42, 18.98 and 18.97 mg/mL for DPPH, FRAP and TAC tests respectively.

Characterization of a Food‐Safe Colorimetric Indicator Based on Black Rice Anthocyanin/PET Films for Visual Analysis of Fish Spoilage

ABSTRACTThe safety of food products is of prime importance for consumers and manufacturers. Many means can be used to validate a food product's safety before it is consumed. This study is about the preparation, characterization and evaluation of a generally recognized as safe (GRAS) sensitive colorimetric sensor that detects volatile gases (TVB‐N) resulting from fish spoilage, thus indicating the pH variation of packaged fish products. This is performed by coating a thin layer of ink sensors on the surface of the supporting matrix (corona‐treated PET). Various visual pH indicators were prepared based on black rice anthocyanin as an FDA‐approved dye. Black rice, which contains more than 80% cyanidin‐3‐glucoside, is the most prevalent anthocyanin component. Because of its low toxicity and high concentration, it can be utilized as a natural food colourant. pH indicators based on black rice can show distinct colours in various pH: from red (low pH) to violet (4–6) and deep purple/blue (6–7), blue (7–9) to yellowish/light brown (9–13) throughout the acid–base reaction by the analyte. The ink formulation was prepared by incorporating a binder system (PVOH‐PEG) for higher surface wettability, a crosslinking agent (citric acid) for higher adhesion, an antifoaming agent (natural vanillin) and acetic acid as a pH fixing agent. Corona treatments affected substrate surface chemistry in this study. The samples with thermal treatment passed the ASTM D3330 tape test, the 8000 passages for dry sponge and the 25 passages for wet sponge through the abrasion method. Anthocyanin concentration in formulated ink based on calculation by UV–vis spectra is 0.240 mg/100 g. Sensitivity tests towards TVB‐N gases were carried out at a temperature of 4°C to evaluate the performance of colorimetric films with formulated ink along with thermal treatment (temperature: 165°C, time: 5 min) using the volatile gases emitted by the fish sample inside the package.

Synthesis, Characterization and Evaluation of the Antimicrobial and Herbicidal Activities of Some Transition Metal Ions Complexes with the Tranexamic Acid.

New tranexamic acid (TXA) complexes of ferric(III), cobalt(II), nickel(II), copper(II) and zirconium(IV) were synthesized and characterized by elemental analysis (CHN), conductimetric (Λ), magnetic susceptibility investigations (μeff), Fourier transform infrared (FT-IR), proton nuclear magnetic resonance (1H-NMR), ultraviolet visible (UV-vis.), optical band gap energy (Eg) and thermal studies (TG/DTG and DTA). TXA complexes were established in 1 : 2 (metal: ligand) stoichiometric ratio according to CHN data. Based on FT-IR and 1H-NMR data the disappeared of the carboxylic proton supported the deprotonating of TXA and linked to metal ions via the carboxylate group's oxygen atom as a bidentate ligand. UV-visible spectra and magnetic moment demonstrated that all chelates have geometric octahedral structures. Eg values indicated that our complexes are more electro conductive. DTA revealed presence of water molecules in inner and outer spheres of the complexes. DTA results showed that endothermic and exothermic peaks were identified in the degradation mechanisms. The ligand and metal complexes were investigated for their antimicrobial and herbicidal efficacy. The Co(II) and Ni(II) complexes showed antimicrobial activity against some tested species. The obtained results showed a promising herbicidal effect of TXA ligand and its metal complexes particularly copper and zirconium against the three tested plants.

Reductive Dynamic and Static Excited State Quenching of a Homoleptic Ruthenium Complex Bearing Aldehyde Groups.

A new homoleptic Ru polypyridyl complex bearing two aldehyde groups on each bipyridine ligand, [Ru(dab)3](PF6)2, where dab is 4,4'-dicarbaldehyde-2,2'-bipyridine, was synthesized, characterized, and utilized for iodide photo-oxidation studies. In acetonitrile (CH3CN) solution, the complex displayed an intense metal-to-ligand charge transfer (MLCT) absorbance maximum at 475 nm (ε = 22,000 M-1 cm-1) and an infrared (IR) band at 1712 cm-1 assigned to the pendent aldehyde groups. Visible light excitation in air-saturated solution resulted in room temperature photoluminescence (PL) with a maximum at 675 nm, a quantum yield, ϕPL = 0.048, and an excited state lifetime, το = 440 ns, from which radiative and nonradiative relaxation rate constants were extracted, kr = 9.1 × 104 s-1 and knr = 1.8 × 106 s-1. Pulsed visible light excitation yielded transient UV-vis and IR absorption spectra consistent with an MLCT excited state; relaxation occurred with the maintenance of two isosbestic points in the visible region, and a lifetime that agreed with that measured by time-resolved PL. Cyclic voltammetry studies in a CH3CN solution with 0.1 M TBAPF6 electrolyte revealed a quasi-reversible oxidation, E°(RuIII/II) = +1.25 V vs. Fc+/0, and three sequential one-electron reductions at -1.10, -1.25, and -1.54 V vs. Fc+/0. An excited state reduction potential of E°(Ru*2+/+) = +0.89 V vs. Fc+/0 was estimated with the Rehm-Weller expression. Titration of tetrabutylammonium iodide, TBAI, into a CD3CN solution of [Ru(dab)3](PF6)2 resulted in significant shifts in the aldehyde H atom and 3,3'-biypridyl resonances that were analyzed with a 1:1 equilibrium model, from which Keq = 460 M-1 was extracted, increasing to 5800 M-1 when the solvent was changed to acetone-d6. Iodide titrations resulted in a significant quenching of the [Ru(dab)3]*2+ lifetime and quantum yield in both CH3CN and acetone solvents. In CH3CN, the quenching was mainly dynamic and well described by the Stern-Volmer model, from which a quenching rate constant, kq, of 4.5 × 1010 M-1 s-1 and an equilibrium constant, Keq, of 8.3 × 103 M-1 were obtained. In acetone, the static quenching pathway by iodide was greatly enhanced, with a Keq of 1.2 × 104 M-1 and a higher kq of 9.2 × 1010 M-1 s-1.

Green and sustainable synthesis of the ZnONPs using leaf extract of Guazuma ulmifolia for antioxidant and antimicrobial activities

AbstractThe main objectives of the current study were synthesis and characterization of zinc oxide nanoparticles (ZnONPs) using the aqueous leaf extract of Guazuma ulmifolia (G. ulmifolia) plant and assessing its antimicrobial and antioxidant potential. The nanoparticles were characterized using Ultraviolet Visible (UV–Vis), Fourier Transform Infrared (FTIR) Spectroscopy, X-ray diffraction (XRD), Energy-dispersive X-ray (EDS) and Scanning electron microscopy (SEM). ZnONPs exhibited a maximum peak at 342 nm in the UV–Vis spectrum, indicating their absorption properties. FTIR analysis confirmed the presence of functional groups, such as OH and COOH which likely contributed to the stability of the nanoparticles. The XRD analysis confirmed the spherical structure of the nanoparticles as indicated by distinct diffraction peaks corresponding to the lattice planes of the ZnO standard. The EDS analysis confirmed the presence of Zn, C and O in the ZnONPs. SEM analysis provided insights into the nanoparticles size, shape and surface morphology, showing an average size between 19 and 41 nm. Furthermore, the synthesized ZnONPs demonstrated excellent antioxidant and antibacterial activities against various bacteria and Candida species. This study highlights the promising potential of ZnONPs in diverse fields, including biomedicine, due to their low toxicity, economic viability and beneficial properties. It is crucial to conduct further in vivo investigations in order to determine the safety, effectiveness and compatibility of G. ulmifolia ZnONPs.

Green route to fabrication of Semal-ZnO nanoparticles for efficient solar-driven catalysis of noxious dyes in diverse aquatic environments.

This work successfully demonstrates a sustainable and environmentally friendly approach for synthesizing Semal-ZnO nanoparticles (NPs) using the aqueous leaf extract of Bombax ceiba L. These NPs exhibit an absorption peak at approximately 390nm in the UV-visible spectrum and an energy gap (Eg) of 3.11eV. Detailed analyses of the morphology and particle size using various spectroscopic and microscopic techniques, XRD, FE-SEM with EDS, and HR-TEM reveal crystallographic peaks attributable to the hexagonal phase, with an average crystal size of 17nm. The Semal-ZnO NPs also exhibit a notable photocatalytic efficiency for degrading methylene blue (MB) and methyl orange (MO) under sunlight in different water samples collected from diverse natural sources, indicating that they are promising photocatalysts for environmental remediation. The photocatalytic efficiency of the biofabricated Semal-ZnO NPs is impressive, exhibiting a photodegradation rate of up to 99% for MB and 79% for MO in different water samples under exposure to sunlight. The novel phytofabricated Semal-ZnO NPs are thus a beacon of hope for the environment, with their desirable photocatalytic efficiency, pseudo-first-order kinetics, and ability to break down noxious dye pollutants in various aquatic environments.

Comprehensive study on the nonlinear optical properties of Ag/MoSe2 composite films

MoSe2 thin films and Ag/MoSe2 composite thin films were prepared by physical vapour deposition (PVD). The morphology and structure of the composite film were characterized by scanning electron microscopy and absorption spectroscopy. The UV–visible absorption spectrum characterizes the linear absorptivity of the composite films. Due to the plasma effect of Ag nanofilms, the Ag/MoSe2 composite films showed a significant increase in the absorption intensity of the films compared to the MoSe2 films. The nonlinear absorption properties of MoSe2 thin films were investigated using the open-aperture Z-scan technique. The calculated nonlinear absorption coefficient (β) showed that the nonlinear absorption coefficient of the Ag/MoSe2 composite film is an order of magnitude higher than that of the MoSe2 film, indicating that the Ag nanofilm can better improve the nonlinear absorption properties of the MoSe2 film.

Study of Antioxidant, Antimicrobial and Cytotoxic Activities of Ag-Co Bimetallic Nanoparticles Biosynthesized from Red Alga (Amphiroa sp.)

Objectives: To biosynthesize, evaluate, and investigate the green synthesis of silver-cobalt bimetallic nanoparticles using red alga Amphiroa sp. and its interactions with human pathogens in a colloidal condition. Methods: The marine red algal extract of Amphiroa sp. was used to synthesize the bimetallic nanoparticles of Ag and Co. For this 50mL of 10-3 aqueous Ag-Co prepared solutions were combined with 50mL of pure algal extract. It was characterized by UV-Vis, FTIR, XRD, and SEM. It was tested for its antioxidant, antibacterial, and cytotoxic activities. The antibacterial activity of bimetallic nanoparticles was tested on five human pathogens Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa. The MTT assay method was used for cytotoxic activity for MCF-7 Breast cancer cell lines. Findings: The green synthesized Amphiroa sp. bimetallic nanoparticles showed a UV-Vis spectrum absorption peak at 517nm. Analysis of the FTIR spectra verified the functional groups involved in the production of the Ag-Co nanoparticles. The diffraction pattern of silver-cobalt nanoparticles and the X-ray diffraction pattern of silver nanoparticles showed diffraction angles at 2θ values of 32.5°(15), 46.5°(11) which correspond to (111), (200), and (220). The particle size distribution, which ranges from 56 to 250nm, and the shape was revealed by SEM investigation to be cubic to rhomboidal, thus, they were confirmed to be nanoparticles as well as fine particles/particulate matter. Radical scavenging activity by DPPH, ABTS, and ferrous-reducing power assays were used to investigate the antioxidant potential. The antibacterial activity of bimetallic nanoparticles was tested on five human pathogens and with the zone of inhibition of 23, 18, and 20 mm for Pseudomonas aeruginosa, Escherichia coli and Bacillus subtilis, respectively. The cytotoxic effect was observed on MCF-7 cancer cell lines were evaluated by MTT assay. The IC50 value of our Ag-Co bimetallic sample was found to be 70.90µg/ml at 200µg/mL concentrations. Novelty: Biosynthesizing and investigating Ag-Co bimetallic nanoparticles using red alga and its characterization, antioxidant, antimicrobial and cytotoxic activity. Keywords: Amphiroa sp.; Ag-Co Bimetallic nanoparticles (BNPs); antioxidant, antibacterial and cytotoxic activity

Towards High-Performance Photo-Fenton Degradation of Organic Pollutants with Magnetite-Silver Composites: Synthesis, Catalytic Reactions and In Situ Insights.

In this study, Fe3O4/Ag magnetite-silver (MSx) nanocomposites were investigated as catalysts for advanced oxidation processes by coupling the plasmonic effect of silver nanoparticles and the ferromagnetism of iron oxide species. A surfactant-free co-precipitation synthesis method yielded pure Fe3O4 magnetite and four types of MSx nanocomposites. Their characterisation included structural, compositional, morphological and optical analyses, revealing Fe3O4 magnetite and Ag silver phases with particle sizes ranging from 15 to 40 nm, increasing with the silver content. The heterostructures with silver reduced magnetite particle aggregation, as confirmed by dynamic light scattering. The UV-Vis spectra showed that the Fe:Ag ratio strongly influenced the absorbance, with a strong absorption band around 400 nm due to the silver phase. The oxidation kinetics of organic pollutants, monitored by in situ luminescence measurements using rhodamine B as a model system, demonstrated the higher performance of the developed catalysts with increasing Ag content. The specific surface area measurements highlighted the importance of active sites in the synergistic catalytic activity of Fe3O4/Ag nanocomposites in the photo-Fenton reaction. Finally, the straightforward fabrication of diverse Fe3O4/Ag heterostructures combining magnetism and plasmonic effects opens up promising possibilities for heterogeneous catalysis and environmental remediation.

Optical and molecular features of negatively curved surfaces created by POPE lipids: A crucial role of the initial conditions

Membrane fusion is closely related to plasma membrane domains rich in cone-shaped phosphatidylethanolamine (PE) lipids that can reverse membrane curvature under certain conditions. The phase transition of PE-based lipid membranes from the lamellar fluid phase (Lα) to the inverse hexagonal phase (HII) is commonly taken as a general model in reconstructing the membrane fusion pathway, and whose structural features have been mostly described so far using structural and microscopic techniques. The aim of this paper is to decipher the optical and molecular features of Lβ → Lα and especially of Lα → HII transition of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) lipids at pH = 7.0 when they are initially prepared in the form of both multi- and unilamellar liposomes (MLVs and LUVs). The distinction between optical properties of MLS- and LUVs-derived HII phase, provided from turbidity-sensitive temperature-dependent UV–Vis spectra, was attributed to different formation mechanisms of HII phase. Most importantly, from FTIR spectroscopic data of POPE lipids in Lβ (15 °C), Lα (50 °C) and HII (85 °C) phases we identified the changes in molecular features of POPE lipids during phase transitions. Among the latter, by far the most significant is different hydration pattern of POPE lipids in MLVs- and LUVs-derived HII phase which extends from the polar-apolar interface all the way to the terminal amino group of the POPE lipid, along with the changes in the conformation of glycerol backbone as evidenced by the signature of α-methylene groups. Molecular dynamics simulations confirmed higher water penetration in HII phase and provided insight into hydrogen bonding patterns.

Unlocking the power of nano Petals: Magnifying Rhodamine 6G detection sensitivity in SERS

The escalating prevalence of hazardous, chromatic dye pollutants necessitates the implementation of a discerning and expeditious detection methodology. This investigation responds to this imperative by introducing silver-coated nickel oxide (Ag@NiO) nanostructured thin films as efficacious substrates for Surface-Enhanced Raman Spectroscopy (SERS). Interrogating the exceptional enhancement capabilities of Ag@NiO nano petals and unraveling the underlying mechanisms governing their formation, the study provides valuable insights into the optimization of SERS substrate fabrication. X-ray diffraction (XRD) analysis affirms the presence of a Face-Centered Cubic (FCC) structure within NiO, accompanied by an average crystallite size ranging from 38 to 53 nm. Scanning electron microscopy (FESEM) images unveil petal-like morphologies with widths fluctuating between 36 and 48 nm. Energy-dispersive X-ray (EDX) analysis validates the elemental composition, while UV–visible spectrum analysis delineates a band gap energy (Eg) spectrum spanning from 3.23 to 3.43 eV. Of particular significance is the showcase of Ag@NiO nano petals' astounding enhancement factor, reaching an impressive 3.2 x 107 for Rhodamine 6G (R6G). This enables detection at an extraordinary limit of 10-7 mol/L. These discernments not only propel advancements in SERS substrate engineering but also harbor implications for the meticulous analysis of R6G dye and other environmental pollutants, thereby enriching the arsenal of chemical sensing and environmental monitoring methodologies.

Two-photon absorption in bioactive C4-substituted Coumarin derivatives: Impact of electron-withdrawing and donating groups in different environment

The versatile applications of coumarin derivatives in materials processing, fluorescence imaging, data storage, and photodynamic therapy have sparked considerable interest in scientific community. In this research paper, we explore the UV–vis spectra, IR spectra, and two photon absorption (TPA) characteristics of biological active coumarin derivatives under the influence of electron withdrawing (specifically X = CONH2, CHO, and NO2) and electron donating (X= -CH3, -OH, -NH2) functional groups at C-4 position. To delve into the absorption spectra, we employ time-dependent density functional theory calculations. Results revealed that acceptor functional groups (specifically R = CONH2, CHO, and NO2) not only lower the energy of the lowest two photon active state but also increase the corresponding TPA cross-section. Furthermore, using the Conductor-like Polarizable Continuum Model (CPCM), the influence of solvent polarity on C-4 substituted coumarin derivative was also investigated. Our findings effectively capture how substitutions and solvents impact the nonlinear optical response in coumarins, as evidenced by the measurement of the two-photon absorption cross-section (σTPA). This study offers valuable insights for identifying and designing novel coumarin derivatives with C4 substitutions, unlocking new and intriguing possibilities for their practical applications.

Enhancing optical and radiation shielding properties: A dive into Bi2O3-Infused glasses

In the world of contemporary glass research, the subtle interplay between composition and resulting properties is of paramount importance. The structural, optical, and gamma-ray attenuation properties of BiNb(x) glasses having a formula xBi2O3–(20-x)Nb2O5–B2O3–Li2O–SiO2 (where x = 0,5,10,15 and 20 mol%) were investigated. This study delves deep into the transformative role of Bi2O3 when introduced into the glass matrix, a journey from opacity to enlightening transparency. The density of the BiNb glass system was found to increase from 4.579 g/cm3 for pristine to 5.439 gm/cm3 for BiNb20. XRD analysis testifies the transfer of a pristine sample from a crystalline to a fully amorphous, with Bi2O3 as the catalyst. UV–visible spectra were investigated, and optical parameters were extracted. The optical bandgap (Eg) was decreased from 4eV for BiNb0 to 3.83eV for BiNb20. In addition, Eg value was used to evaluate the refractive index of the prepared BiNb glasses using various theoretical models. The refractive index of the Moss model increases from 2.208 for BiNb0 to 2.229 for BiNb20, besides the Moss, Herve-Vandamme, and Kumar-Singh models are compatible. The studied glass samples show a metallization criterion within the range of 0.434–0.447, indicating the potential for new optical materials with good nonlinearity. Moreover, gamma rays with energy ranging from 0.015 MeV to 15 MeV are used to highlight the shielding capabilities of the glasses. As the Bi2O3 fraction increases and the Nb2O5 decreases, the shielding capability of the prepared BiNb glass system increases.

Maximizing the value of liquid products and minimizing carbon loss in hydrothermal processing of biomass: an evolution from carbonization to humification

Hydrothermal carbonization (HTC) converts wet biomass into hydrochar and a process liquid, but aromatic compounds in the products have been reported as a roadblock for soil applications as they can inhibit germination, plant growth, and soil microbial activity. Here, we compared HTC and hydrothermal humification (HTH) of cow manure digestate while varying the initial alkaline content by adding KOH. HTH converted 37.5 wt% of the feedstock to artificial humic acids (A-HAs) found in both solid and liquid, twice that of HTC. HTH reduced phenolic and furanic aromatic compounds by over 70% in solids and 90% in liquids. The A-HAs in HTH resemble natural humic acids (N-HA), based on FTIR, UV–vis spectra, and CHN and XRD analysis. The HTH liquid possesses 60% higher total organic carbon (TOC) than HTC. Although one-third of TOC can be precipitated as A-HA, a high TOC concentration remains in the liquid, which is shown to be mainly organic acids. Therefore, we also evaluated the HTC and HTH liquids for anaerobic biomethane production, and found that compared to the original cow manure digestate, the HTH liquids increased methane yield by 110.3 to 158.6%, a significant enhancement relative to the 17.2% increase seen with HTC liquid. The strong reduction in organic acids during biogas production from HTH liquid indicates the potential for converting soluble byproducts into methane, while maintaining high A-HAs levels in the solid product.Graphical

Rigid symmetric Rhodamine fluorescent dyes as fast selective detection of aluminum and iron ions applied to cell imaging

Fluorescent probe molecules have the advantages of good selectivity, high sensitivity, and easy operation, which have attracted much attention. In this paper, a novel symmetric rhodamine fluorescent probe with structural rigidity was synthesized by a simple reaction using rhodamine 6G as raw material. And it was characterized by NMR and electrospray spray mass spectrometry. Single crystal was prepared by solvent evaporation method, which was the first single crystal of the compound reported domestically and internationally. Special spiral ring structures were observed inside the crystal. Among different competing cations, the probe exhibited high selectivity and good sensitivity towards Al3+ and Fe3+ metal ions. The limits of detection were 0.76 nM and 0.49 nM, respectively. In the presence of Al3+ and Fe3+, the solution changed from colorless to pink. At the same time, there was a significant shift in the UV–vis spectrum and fluorescence emission spectrum. The UV–vis absorption peak appeared at 530 nm, while the emission at 556 nm was turned on. In addition, biological experiments have shown that the RP probe has good membrane permeability and has the potential to detect Al3+ and Fe3+ in Hela cells.

Plant-assisted green preparation of silver nanoparticles using leaf extract of Dalbergia sissoo and their antioxidant, antibacterial and catalytic applications.

Plant-mediated preparation of silver nanoparticles (AgNPs) is thought to be a more economical and environmentally benign process in comparison to physical and chemical synthesis methods. In the present study, the aqueous leaf extract of Dalbergia sissoo was prepared and utilized to reduce silver ion (Ag+) during the green synthesis of silver nanoparticles (DL-AgNPs). The formation of DL-AgNPs was verified using UV-Vis spectra, exhibiting the surface plasmon resonance (SPR) band at around 450nm. FT-IR analysis revealed the kinds of phytochemicals that serve as reducing and capping agents while DL-AgNPs are being synthesized. Analysis of scanning electron microscope (SEM) and high-resolution transmission electron microscopy (HR-TEM) images verified the development of spherical and oval-shaped DL-AgNPs, with sizes ranging from 10 to 25nm. The stability and particle size distribution of synthesized DL-AgNPs were ensured by zeta potential and DLS (dynamic light scattering) investigations. Additionally, X-ray diffraction (XRD) analysis confirmed the crystalline nature of DL-AgNPs. In antioxidant experiments, DL-AgNPs demonstrated significant scavenging capacities of DPPH and ABTS radicals with EC50 values of 51.32 and 33.32μg/mL, respectively. The antibacterial activity of DL-AgNPs was shown to be significant against harmful bacteria, with a maximum zone of inhibition (21.5 ± 0.86mm) against Staphylococcus aureus. Furthermore, DL-AgNPs exhibited effective catalytic activity to degrade environment-polluting dyes (methylene blue, methyl orange, and Congo red) and toxic chemicals (p-nitrophenol). The results of all these studies suggested that DL-AgNPs made from the leaf extract of Dalbergia sissoo have merit for application in the environmental and biomedical fields.

Dual-responsive solvatochromic sensor for simultaneous detection and mechanism of Cr(III) and Co(II) cations by a new N2O4-donor tetrabenzodiaza-crown ether Macrocyclic ligand anchored to dipyridine moieties

The present study describes the chemosensing capability of an N2O4-donor tetrabenzodiaza-crown ether macrocyclic ligand derivatized by two pyridine side arms to afford the flexible macrocyclic ligand, 5,20-bis(pyridin-4-ylmethyl)-5,6,12,13,19,20,26,27octahydrotetrabenzo [e,i,o,s][1,4,11,14]tetraoxa[7,18]diazacycloicosine (PMHBOA). A selective colorimetric behavior of PMHBOA for the prompt detection of Cr(ΙΙΙ) and Co(ΙΙ) can be observed with naked eyes. The 1H, 13C{H} NMR, and infrared spectroscopy disclosed the ligand binding capability for selective metal ions, ascribed to a 1:1 complex formation with Cr(III) and Co(II) cations in isopropanol. The limit of detection (LOD) values were calculated as 580 and 850 nM for Cr(ΙΙΙ) and Co(ΙΙ), respectively, accompanied with suitable LOQs as 1.95 µM for Cr(III) and 2.85 µM for Co(II), respectively. The reusability was confirmed in the presence of ethylenediaminetetraacetic acid (EDTA). Moreover, a TLC-based fabricated paper strip successfully applied PMHBOA as a chemosensor for synchronous visible detection of Cr(III) and Co(II) in their alcoholic solution. Meanwhile, the observed color change along with the turn-off fluorescent of PMHBOA guaranteed a felicitous choice of candidate for Cr(III) in the presence of other library metal ions in isopropanol:H2O (9/1 v/v) solution. A fast separation test on the filter paper, impregnated with PMHBOA, was also employed to separate Cr(III) and Co(II) cations from aqueous solutions by recording UV–vis spectra. The 1H NMR spectroscopy supported the macrocycle ring and side arms as the parallel coordination site of PMHBOA with Cr(III) and Co(II).