Ultraviolet-visible Spectroscopy Research Articles

Catharanthus roseus-mediated CuAl2O4 Nanocomposites for Evaluation of Killing Kinetics.

The present article portrayed on the killing kinetic of human pathogenic bacteria using bioinspired mesoporous CuAl2O4 nanocomposites (NCs). The NCs was fabricated using leaf extract of medicinal plant Catharanthus roseus (CR) as a green reducer and stabilizer. As bio-fabricated material was calcined at 800 °C and characterized by several analytical techniques like X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-DRS), Energy Dispersive X-Ray Spectroscopy (EDS), X-Ray Photoelectron Spectroscopy (XPS), Raman, Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) to authenticate its structure, phase, chemical bonding, chemical state, size and morphology behaviors. XRD and TEM revealed a reduced crystallite and nanoscale sizes of biosynthesized NCs. Moreover, XRD study exposed a cubic-structure of material, while transmission electron microscopy rendered an average particles size in range 10-15 nm. However, BET profile advocates a mesoporous nature of the particles. An effective biological molecular docking modulation assessed by substituting natural inhibitor by bioinspired NCs, while the protein PDB ID 4Z8D FabH as a receptor site for the present investigation. After assessment of molecular docking examination, the antibacterial activity of bioinspired NCs were performed against Staphylococcus aureus, Bacillus subtillis, Klebsiella pneumoniae and Escherichia coli using agar-well method. The broth culture method was employed on different pathogenic strains by kinetic growth assays and colony forming unit.

Effect of Oligoricinoleic Acid on Degradation of Polylactic Acid

ABSTRACT The objective of this research is to explore the impact of oligoricinoleic acid (ORA) on the degradation of polylactic acid (PLA). ORA was synthesized from ricinoleic acid using tin (II) 2-ethylhexanoate as a catalyst. The chemical structures of the obtained ORA were confirmed by Fourier-transform infrared spectrometer (FT-IR) and proton nuclear magnetic resonance spectroscopy (1H-NMR). PLA/ORA films were prepared through the casting method by varying ORA concentrations as 0.1%wt, 0.3%wt, 0.5%wt, 1.0 wt%, and 3.0%wt. Degradation of the films via hydrolysis was studied by soaking the films in deionized water and stirring at 120 rpm in an incubator at 37°C. Alterations in the structure and properties of the films were investigated after soaking for 7, 14, 21, and 28 days using ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectrometer (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD), differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), and universal testing machine (UTM). Gel permeation chromatography (GPC) was performed to confirm the decrease in molecular weight (MW). The presence of 3%wt ORA could promote both ductility and degradation of PLA films. ORA further enhances thermal stability, indicating potential for prevention of thermal degradation during melt processing.

Improved Synthesis of Cu2O NPs and Ascorbic Acid-Modified Derivatives for Adsorption of Brilliant Cresyl Blue: Surface and Reusability Studies

This study addresses the critical need for efficient and recyclable photocatalysts for water treatment applications by presenting a novel approach for the synthesis and characterization of copper (I) oxide (Cu2O) nanoparticles modified with ascorbic acid (Cu2O/AA). The motivation for this research stems from the increasing concern about environmental pollution caused by organic pollutants, such as Brilliant Cresyl Blue (BCB), and the necessity for sustainable solutions to mitigate this issue. Through comprehensive characterization techniques including Ultraviolet–Visible spectroscopy (UV-Vis), Fourier Transform Infrared spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), zeta potential measurements, and Brunauer–Emmett–Teller (BET) analysis, we demonstrate a significant modification to the electronic structure, enhancing the photocatalytic activity of Cu2O/AA. BET analysis revealed a mesoporous structure with a specific surface area of 2.7247 m2/g for Cu2O/AA, further emphasizing its potential for enhanced catalytic performance. The photocatalytic degradation studies showcased remarkable efficiency improvements, with degradation coefficients of 30.8% and 73.12% for Cu2O NPs and Cu2O/AA NC, respectively, within a 120 min timeframe. Additionally, recyclability experiments indicated sustained efficiency over five consecutive cycles, with both catalysts retaining crystalline integrity. These findings underscore the promising potential of Cu2O/AA nanoparticles as highly efficient and recyclable photocatalysts for the degradation of organic pollutants, offering superior performance compared to pure Cu2O NPs and addressing the pressing need for sustainable water treatment solutions.

Cu/Co Bimetallic Carbon Catalyst as a Highly Efficient Promoter for Reactive Dyes Degradation with PMS.

The synergistic effect between bimetallic catalysts has been confirmed as an effective method for activating persulfate (PMS). Therefore, we immobilized copper-cobalt on chitosan to prepare bimetallic carbon catalysts for PMS activation and degradation of reactive dyes. Experimental results demonstrate that the CuCo-CTs/PMS catalytic degradation system exhibits excellent degradation performance toward various types of reactive dyes (e.g., Ethyl violet, Chlortalidone, and Di chlorotriazine), with degradation rates reaching 90% within 30 min. CuCo-CTs exhibit high catalytic activity over a wide pH range of 3-11 at room temperature and under static conditions, degrading over 92% of RV5 within 60 min. ultraviolet-visible (UV-vis) spectroscopy and color changes in the dye solution confirm the effective degradation of RV5, with a degradation rate of 97.2% within 10 min. Additionally, CuCo-CTs demonstrate good stability and reusability, maintaining a degradation rate of 92.8% after eight cycles. Kinetic studies indicate that the degradation follows pseudo-first-order kinetics. Furthermore, based on the results of radical scavenging experiments, the catalytic degradation mechanism of the dye involves both radical and nonradical pathways, with 1O2 identified as the primary active species. This study provides insights and experimental evidence for the application of persulfate oxidation in the treatment of dyeing wastewater.

Synthesis, Characterization, and Properties of a Titanium(IV)-Tetrathiafulvalene-Based Complex.

To deeply investigate the interaction between a tetrathiafulvalene (TTF) unit and a Ti(IV) center, a monomeric heteroleptic octahedral Ti(IV) complex containing a diimine ligand composed of a 1,10-phenanthroline core fused with a TTF fragment (ligand 2a) was prepared. The stable complex formulated as Ti(1)2(2a), where 1 is a 2,2'-biphenolato derivative, was efficiently synthesized by following a one-step approach. This complex and its model species [Ti(1)2(2b)] were fully characterized in solution, and their solid-state structures were established by single-crystal X-ray diffraction analysis. Density functional theory calculations allowed the assignment of the frontier orbitals involved in the electronic transitions characterized by ultraviolet-visible absorption spectroscopy. Electrochemical and spectroelectrochemical studies revealed that the TTF unit within Ti(1)2(2a) can undergo two reversible one-electron oxidation processes; a reversible one-electron reduction of the Ti(IV) atom was highlighted. The photophysical measurements performed for this donor-acceptor molecular system indicated that an electron transfer process upon light excitation occurred within Ti(1)2(2a).

Optimization of ultrasonic pretreatment and analysis of chlorogenic acid in potato leaves

Chlorogenic acid (CA) is an effective ingredient that can strengthen immunity during following the COVID-19 era. The current cost of CA is high owing to its complex purification process and low yield (approximately 2%). In this study, a one-step path orthogonal experiment was designed based on the results from Gauss calculation, which consisted of acidity, coordination, and hydrolysis in molecules. The optimized extraction conditions were 60 ℃, 60 min, 1:20 liquid ratio, and 40% ethanol in a nitrogen atmosphere controlled using a device of our own design, which led to CA yields of up to 6.35% from potato leaves. The purified CA was analyzed using high-performance liquid chromatography, thin-layer chromatography, ultraviolet–visible spectroscopy, and molecular fluorescence. This accurate and reproducible method can not only be used to obtain high yields of CA but can also be used for the quality control of active plant products and their isomers.

The role of reduced graphene oxide on mitigation of lead phytotoxicity in Triticum aestivum L.plants at morphological and physiological levels

Rapid global industrialization and an increase in population have enhanced the risk of heavy metals accumulation in plant bodies to disrupt the morphological, biochemical, and physiological processes of plants. To cope with this situation, reduced graphene oxide (rGO) NPs were used first time to mitigate abiotic stresses caused in plant. In this study, rGO NPs were synthesized and reduced with Tecoma stans plant leave extract through modified Hummer's methods. The well prepared rGO NPs were characterized by ultra-violet visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Zeta potential, and scanning electron microscopy (SEM). However, pot experiment was conducted with four different concentrations (15, 30, 60, 120 mg/L) of rGO NPs and three different concentrations (300, 500,700 mg/L) of lead (Pb) stress were applied. To observe the mitigative effects of rGO NPs, 30 mg/L of rGO NPs and 700 mg/L of Pb were used in combination. Changes in morphological and biochemical characteristics of wheat plants were observed for both Pb stress and rGO NPs treatments. Pb was found to inhibit the morphological and biochemical characteristics of plants. rGO NPs alone as well as in combination with Pb was found to increase the chlorophyll content of wheat plants. Under Pb stress conditions and rGO NPs treatments, antioxidant enzyme activities like ascorbate peroxidases (APX), superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were observed. Current findings revealed that greenly reduced graphene oxide NPs can effectively promote growth in wheat plants under Pb stress by elevating chlorophyll content of leaves, reducing the Pb uptake, and suppressing ROS produced due to Pb toxicity.

Fabrication of sulfobutylether-β-cyclodextrin/glabridin inclusion complex for promoting bioactivities.

As the main active compound of Glycyrrhiza glabra L., glabridin (GLD) has been shown to have multiple bioactivities, whereas the clinical application of GLD is restricted by its low water solubility. In this study, GLD was encapsulated into a sulfobutylether-β-cyclodextrin (SBE-β-CD)-based inclusion complex (SBE-β-CD/GLD) by the freeze-drying method. The materials characterization, antibacterial activity, stimulated cellular behavior and in vivo full-thickness diabetic wound healing ability of the hydrogels were assessed and analyzed. The successful encapsulation of the inclusion complex was confirmed by ultraviolet (UV) visible spectroscopy, Fourier transform infrared (FT-IR), X-ray diffractometer (XRD), scanning electron microscope (SEM), and nuclear magnetic resonance (NMR). SBE-β-CD as an excipient significantly enhances the water solubility of GLD, and SBE-β-CD/GLD showed excellent biocompatibility on human vascular endothelial cells (HUVECs) and erythrocytes. The SBE-β-CD/GLD inclusion complex exerted a pronounced antibacterial activity on Staphylococcus aureus and Escherichia coli in vitro. The SBE-β-CD/GLD inclusion complex markedly enhanced the antioxidant activity compared with free GLD. The SBE-β-CD/GLD inclusion complex potently accelerates the healing of full-thickness skin defects by inhibiting inflammation. The outcomes suggest that SBE-β-CD could be used as a promising drug delivery system for the clinical application of GLD.

Novel green synthesis of Value-Added graphene quantum dots from bagasse and pith for biological applications

The continuing rush for potential biomedical applications has sparked the fabrication of graphene quantum dots (GQDs) particularly from agricultural waste. GQDs are unique among carbon-based nanomaterials due to their flexibility, chemical stability, size control, and non-toxic nature. In this study, we have developed Graphene Quantum dots from sugarcane bagasse (GQDs-SB) and sugarcane bagasse pith (GQDs-SBP) by carbonization followed by microwave pyrolysis. The optical properties of the synthesized GQDs-SB and GQDs-SBP were characterized by Ultraviolet–Visible spectroscopy and Photoluminescence (PL) analysis and the surface functional groups were determined by FT- IR analysis. The High resolution transmission electron microscopy (HR-TEM) was used to examine dimensions and structure of GQDs-SB and GQDs-SBP. The storage stability of GQDs-SB and GQDs-SBP was monitored using Ultraviolet–Visible spectroscopy. The synthesized GQDs-SB and GQDs-SBP were evaluated for biological applications like anti-oxidant activity, anti inflammatory activity and cytotoxic effect was also assessed. GQDs-SB and GQDs-SBP demonstrated significant antioxidant and anti-inflammatory effects due to their great ability to scavenge free radicals and extraordinary water solubility. The synthesized GQDs-SB and GQDs-SBP were less toxic in nature.

Antibacterial efficacy of Rumex dentatus leaf extract-enriched zinc oxide and iron doped zinc nanoparticles: a comparative study

In the current investigation, zinc oxide (ZnO) nanoparticles and Fe-doped ZnO nanoparticles were sustainably synthesized utilizing an extract derived from the Rumex dentatus plant through a green synthesis approach. The Scanning electron microscope (SEM), X-ray diffraction (XRD), Energy-dispersive x-ray spectroscopy (EDX), Ultra-violet visible spectroscopy (UV–vis) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and Thermogravimetric analysis (TGA) techniques were used to examine the compositional, morphological, optical, and thermal properties of both samples. The doping of iron into ZnO NPs has significantly influenced their properties. The analysis firmly established that both ZnO NPs and Fe-doped ZnO NPs have hexagonal wurtzite structures and spherical shapes by XRD and SEM. The EDX analysis suggests that iron atoms have been successfully integrated into the ZnO lattice. The change in color observed during the reaction indicated the formation of nanoparticles. The UV–vis peaks at 364 nm and 314 nm confirmed the presence of ZnO NPs and Fe-doped ZnO NPs, respectively. The band gap of ZnO NPs by Fe dopant displayed a narrowing effect. This indicates that adding iron ions to ZnO NPs offers a control band gap. The thermal study TGA revealed that Fe-doped ZnO NPs remain stable when heated up to 600 °C. The antibacterial efficacy of ZnO NPs and Fe-doped ZnO NPs was evaluated against several bacterial strains. The evaluation is based on the zone of inhibition (ZOI). Both samples exhibited excellent antibacterial properties as compared to conventional pharmaceutical agents. These results suggest that synthesizing nanoparticles through plant-based methods is a promising approach to creating versatile and environmentally friendly biomedical products.

Chemiresistive Materials for Alcohol Vapor Sensing at Room Temperature

The development of efficient sensors able to detect alcoholic compounds has great relevance in many fields including medicine, pharmaceuticals, food and beverages, safety, and security. In addition, the measurements of alcohols in air are significant for environmental protection because volatile alcohols can have harmful effects on human health not only through ingestion, but also through inhalation or skin absorption. The analysis of alcohols in breath is a further expanding area, being employed for disease diagnoses. The analyses performed by using chromatography, mass-spectrometry, nuclear magnetic resonance, ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, or Raman spectroscopy often require complex sampling and procedures. As a consequence, many research groups have focused their efforts on the development of efficient portable sensors to replace conventional methods and bulky equipment. The ability to operate at room temperature is a key factor in designing portable light devices suitable for in situ real-time monitoring. In the present review, we provide a survey of the recent literature on the most efficient chemiresistive materials for alcohol sensing at room temperature. Remarkable gas-sensing performances have mainly been obtained by using metal oxides semiconductors (MOSs), metal organic frameworks (MOFs), 2D materials, and polymers. Among 2D materials, we mainly consider graphene-based materials, graphitic carbon nitride, transition metal chalcogenides, and MXenes. We discuss scientific advances and innovations published in the span of the last five years, focusing on sensing mechanisms.

STUDY OF THE INHIBITORY EFFECTS OF VITAMIN E DERIVATIVES ON MITOCHONDRIAL COMPLEX II SUBUNIT USING MOLECULAR DOCKING

Objective: The goal of this study was to create vitamin E derivatives and explore their potential anticancer properties using a computational approach. Methods: The Steglich method was used for the synthesis of the vitamin E-fatty acid (pentanoic acid, heptanoic acid, and octanoic acid) derivatives, with N,N'-dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP) as the catalysts. The structure of the synthesized products was determined by ultraviolet-visible (UV-Vis) spectroscopy, fourier transform infrared (FTIR) spectroscopy, and liquid chromatography-mass spectrometry (LC-MS). Molecular docking was carried out on the succinate dehydrogenase (SDH) enzyme using AutoDockTools. Results: α–Tocopherol pentanoate (α–TP), α–tocopherol heptanoate (α–TH), and α–tocopherol octanoate (α–TO) were the three vitamin E derivatives synthesized in this study. Based on the results of molecular docking, the novel compounds (α–TP, α–TH, and α–TO) generated bond energies of-10.57,-9.61, and-9.20 kcal/mol, respectively. Conclusion: All newly synthesized compounds exhibited lower binding affinity values than α–tocopherol (α–T). This confirms that these compounds might not provide greater advantages than α-tocopherol in terms of inhibitory effects on mitochondrial complex II (CII).

SYNTHESIS OF Ag-MODIFIED TiO2 SOL-GEL FILMS AND ITS APPLICATION AS PHOTOCATALYSTS FOR METHYLENE BLUE DEGRADATION

In the study, the photocatalytic activity of TiO2 films that are created by dip-coating from a sol that contained titanium (IV) isopropoxide, monoethanolamine, and 2-methoxyethanol is demonstrated. Through photo-fixation of Ag (I) ions with varied concentration (10-2 - 10-4 M) in the water phase under UV illumination, the films are subsequently surface-modified with Ag co-catalyst layers. Scanning Electron Microscopy (SEM), X-Ray Photoelectron Spectroscopy (XPS), Ultraviolet-Visible (UV) Spectroscopy, and Electron Paramagnetic Resonance (EPR) techniques are used to physically characterize the samples. Results reveal that the modification of the co-catalyst had no impact on the thickness and porosity of the films. In addition, the study show that the modified TiO2 films had increased photocatalytic activity. All the characterization methods used have shown the formationof surface - bound Ag (I) species and metallic silver nanoclusters. By measuring the Methylene Blue (MB) dye degradation under UV light illumination, as - prepared and Ag -modified TiO2 films are evaluated for their photocatalytic activity, and the impact of the silver precursor concentration during photo-fixation is investigated.The highest catalytic activity is seen for films that have been modified at a concentration of Ag (I) of 10-2 M. Ordered from highest to lowest, the MB photodegradation rate constants are TiO2 < TiO2 /Ag, 10-4 < TiO2 /Ag, 10-3 < TiO2 / Ag, 10-2.

Optimizing Green Synthesis of Hydrotalcite - Silver Nanoparticles using Syzygium Nervosum based Reducing Agent.

This work aimed to assess the effect of Syzygium nervosum leaf extract as a reducing agent for green synthesis of AgNPs on HT through an optimizing process using response surface methodology (RSM) and the Box-Benken model. The optimal conditions for synthesis of AgNPs on HT include reaction time of 6.15 hours, reaction temperature of 50 oC and the ratio of diluted Syzygium nervosum leaf extract to reduce AgNO3 of 50.37 mL/mg. Under the optimal conditions, the yield of reduction reaction reached 77.54 %, close to the theoretical value of 76.97 %.Besides, the morphology, density, and characteristics of AgNPs on the surface of HT layers have been determined by using Ultraviolet-visible spectroscopy, Field emission scanning electron microscopy, High resolution transmission electron microscopy, selected area diffraction, X-ray diffraction, Dynamic light scattering, Infraredspectroscopy, Fluorescence emission spectroscopy, Brunauer-Emmett-Teller methods. The spherical AgNPs were synthesized successfully on the surface of HT with the average particle size of 13.0 ± 1.1 nm. Interestingly, HT-Ag hybrid materials can inhibit strongly the growth of E. coli, S. aureus as well as two antibiotic resistance bacterial strains, P. stutzeri B27 and antibiotic resistance E. coli. Overall, the HT-Ag hybrid materials are very promising for application in practice.

Stability Indicating Method Development and Validation of Glycyrrhizin Using RP-HPLC-DAD: Application to Glycyrrhiza glabra Extract.

Glycyrrhiza glabra is commonly known as licorice. Licorice is the major source of glycyrrhizin. There is no reported stability indicating method for glycyrrhizin in the literature so far. Therefore, it was proposed to develop a stability indicating method and validate the method for glycyrrhizin and its application in G. glabra root extract. Method validation parameters were performed as per the International Council for Harmonization guidelines. The chromatographic separation was achieved on a Zorbax Extended C-18 (250 × 4.6mm, 5μm) column. The separation achieved using the mobile phase consisted of 0.1% formic acid in water and acetonitrile in gradient elution. The flow rate was kept at 1mL/min, and ultraviolet-visible spectroscopy detection was at 250nm. The average retention time of glycyrrhizin was found to be 7.30min. Stress degradation studies were performed and confirmed that only acidic degradation has shown a degradation profile of glycyrrhizin up to 40%. The percentage of glycyrrhizin was found to be 0.40% in the G. glabra extract. This may be further explored for commercial applications.

Visible-light-driven photocatalytic degradation of doxycycline using TiO2/g-C3N4/BIOCHAR catalyst

Abstract TiO2/g-C3N4/biochar (TCNBC) catalysts were prepared by the hydrolysis method for the photocatalytic degradation of doxycycline antibiotic (DC), with biochar obtained from the pyrolysis of Phragmites australis. The catalysts were examined using scanning electron microscope (SEM), transmission microscopy (TEM), energy dispersive X-ray spectrometer (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), photoluminescence spectroscopy (PL), and ultraviolet-visible diffuse reflectance spectroscopy (UV–Vis DRS) and nitrogen adsorption/desorption. The photocatalytic activity results showed that the TCNBC catalyst exhibited higher catalytic activity than pure TiO2 or g-C3N4. Its peak catalytic activity, achieving a decomposition efficiency of 91.93% and a mineralization efficiency of 81.50%, can be attributed to the synergistic effect of biochar, TiO2, and g-C3N4. Even after four cycles of use, the catalyst still maintained relatively high activity for the degradation of DC. The photocatalytic degradation efficiency of TCNBC decreased from 91.93% to 86.30% after four recycling events.

Alginate Nanoparticles Containing Cuminum cyminum and Zataria multiflora Essential Oils with Promising Anticancer and Antibacterial Effects.

Cancer and bacterial infections are major global health concerns driving the need for innovative medicines. This study investigated alginate nanoparticles loaded with essential oils (EOs) from Cuminum cyminum and Zataria multiflora as potential drug delivery systems. The nanoparticles were comprehensively characterized using techniques such as gas chromatography-mass spectrometry (GC-MS), dynamic light scattering (DLS), zetasizer, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and ultraviolet-visible spectroscopy (UV-Vis). Their biological properties against two human skin cancer cell lines (A-375 and A-431) and three bacteria (Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus) were also evaluated. Alginate nanoparticles containing C. cyminum and Z. multiflora EOs exhibited sizes of 160 ± 8 nm and 151 ± 10 nm, respectively. Their zeta potentials and encapsulation efficiencies were -18 ± 1 mV and 79 ± 4%, as well as -27 ± 2 mV and 86 ± 5%, respectively. The IC50 values against the tested cell lines and bacteria revealed superior efficacy for nanoparticles containing Z. multiflora EO. Considering the proper efficacy of the proposed nanoparticles, the straightforward preparation method and low cost suggest their potential for further in vivo studies.

Spectral fusion-based machine learning classifiers for discriminating membrane breakage in multiple scenarios

Membrane breakage can lead to filtration failure, which allows harmful substances to enter the effluent, posing potential hazards to human health and the environment. This study is an innovative combination of fluorescence and ultraviolet-visible (UV–Vis) spectroscopy to identify membrane breakage. It aims to unravel more comprehensive information, improve detection sensitivity and selectivity, and enable real-time monitoring capabilities. Fluorescence and UV–Vis data are extracted through variance partitioning analysis (VPA) and integrated through a decision tree algorithm to form a superior system with enhanced discrimination capabilities. VPA improves discrimination efficiency by extracting key information from spectral data and eliminating redundancy. The decision tree algorithm, on the other hand, can process large amounts of data simultaneously. In addition, the method has a wide range of applications and can be used in various scenarios accurately. The scenarios include domestic sewage, micropollutant water, aquaculture wastewater, and secondary treated sewage. The experimental results validate the application of machine learning classifiers in membrane breakage detection with an accuracy rate of 96.8 % to 97.4 %.

Discrimination of Brazilian green canephora coffees beans by ultraviolet–visible spectroscopy as non-target analysis: A tool for recognizing geographical indications

Specialty green coffee beans have a higher commercial value and some of them have recently been classified in Brazil based on the indication of provenance and denomination of origin. In this context, the classification of the type of coffee bean is still a challenge, using traditional analytical techniques. Thus, alternative analytical techniques, such as ultraviolet–visible spectroscopy (UV–Vis), as non-target analysis can be applied as a quick and reliable method of coffee classification using data science, such as chemometric tools. In the present study, UV–Vis were evaluated as a new strategy for discrimination of green beans of Brazilian specialty canephora coffees with recognized geographical indications (Robusta Amazônico and Conilon from state of Espírito Santo), for the first time. Spectra obtained from the aqueous extract of 221 samples. The Principal Component Analysis (PCA) was performed and subsequently Partial Least Squares with Discriminant Analysis (PLS-DA) model developed. The PCA indicated tendency to group the samples in their respective classes, pointing to the similarities in the spectra of samples of the same origin. The PLS-DA model obtained showed figures of merit values starting at 89.3% in the test set. The VIP scores showed that the variables associated with chlorogenic acids, caffeine and chlorophyll are the most important for differentiating the studied coffees. The results obtained showed that UV–Vis fingerprint − non-targeted analysis associated with PLS-DA is appropriate for the discrimination of green beans of Brazilian specialty coffee from different origins, in a simple way, using common equipment in several laboratories.

Enhancing photocatalytic efficiency of type II V2O5/TiO2 heterojunctions for malachite green dye using solar simulator irradiation

Photocatalytic responses and synergistic effects of V2O5, TiO2, and V2O5/TiO2 heterostructures with varied ratios have been investigated, revealing promising outcomes. The successful synthesis of nanostructures and heterostructures was verified through energy-dispersive X-ray spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy analyses. Notably, ultraviolet–visible spectroscopy and photoluminescence spectral studies confirmed that the optical band gap of V2O5/TiO2 heterostructures increases with higher TiO2 concentrations. These findings enhance our understanding of the agglomerated heterostructures of V2O5/TiO2, particularly with ratios of 1:1 and 1:3, showcasing potential applications in photocatalysis. Furthermore, their performance was subjected to Malachite Green dye degradation using a solar simulator, achieving an impressive efficiency of 93.29%. Additionally, the photocatalytic efficacy was assessed through reusability experiments over three cycles. Remarkably, the heterostructures exhibited stability across these cycles, suggesting their potential for extended use in diverse photocatalytic purposes. The importance of these results is the applicability of our fabricated V2O5/TiO2 heterostructures as a photocatalyst with high performance, especially in the realm of sustainable and efficient dye degradation processes.