UV-Vis Spectrophotometer Analysis Research Articles

A simple technique for the determination of molybdenum (Ⅵ) based on dispersive surfactant micelle-mediated extraction and image colorimetric analysis

ABSTRACT In this study, the potential of dispersive surfactant micelle-mediated extraction combined with image colorimetric analysis was assessed for the extraction, preconcentration, and determination of molybdenum (VI) in environmental samples. In this approach, the cationic cetyltrimethylammonium bromide surfactant (CTAB) was utilised as a complexing and extraction agent, and ethanol was chosen as a dispersive solvent and surfactant self-assembly agent. Initially, a mixture of CTAB and ethanol is injected into a test tube, resulting in the formation of a cloudy solution due to the dispersion of CTAB particles in the aqueous phase. In this step, coloured ternary complexes obtained from the reaction of the Mo(VI) ions with pyrogallol red (PR) in the presence of iodide ions are extracted by CTAB through a surfactant self-assembly process. After centrifuging, the surfactant-rich phase was dissolved in 1 mL of dimethylformamide (DMF) and analysed using a smartphone-based self-constructed colorimeter and a commercial UV-Vis spectrophotometer. In the mentioned colorimeter, digital image analysis of the final solution was performed based on the RGB (Red, Green, Blue) colour model, and the value of the R channel was used to acquire the analytical signal. Under optimal conditions, a linear range of 5–100 μg L−1 and a limit of detection (LOD) of 2.1 μg L−1 were achieved using a self-constructed colorimeter. Additionally, linear range of 15–250 μg L−1, with a LOD of 3.3 μg L−1, was obtained through UV-Vis spectrophotometric analysis. Ultimately, the proposed method was successfully utilised to determine Mo(VI) in various aqueous samples, with satisfactory recoveries ranging from 96 to 109%.

Synthesis and Characterization of Cellulose <i>Nata de Coco</i> Inserted Nanoparticles Zn-Moringa Leaf Extract (<i>Moringa oleifera</i>) as Biodegradable plastic Banan Fruit Packaging

Synthesis and characterization of cellulose nata de coco inserted nanoparticles of zinc-moringa leaf extract as biodegradable plastic for banana fruit packaging has been carried out. This study aims to determine the characteristics, biodegradability and preservation activity of biodegradable plastic cellulose nata de coco inserted zinc nanoparticles-moringa leaf extract. The research process was carried out through the nata de coco synthesis stage, zinc nanoparticle synthesis-moringa leaf extract and the manufacture of biodegradable plastics. The success of this synthesis is evidenced by being characterized using a UV-Vis spectrophotometer, FTIR spectrophotometer and digital optical microscope. The results of UV-Vis spectrophotometer analysis showed that the zinc nanoparticles formed had an estimated particle size of 85.72-92.92 nm and were stable. The results of FTIR analysis on Moringa leaf extract showed the presence of -OH, C-H, C=O, C=C and C-O groups. In the biodegradable plastic film nata de coco-NPZn-moringa leaf extract, there was a peak shift in several functional groups marked at the peaks of wavenumbers 555.50 and 432.05 cm-1 which are ZnZP groups. Characterization using a digital optical microscope showed that zinc nanoparticlesThe synthesis is spherical, non-uniform, and has been well distributed on the cellulose surface of nata de coco. Biodegradation test on nata de coco-NPZn-Moringa leaf extract biodegradable plastic film using activated sludge system, test results show biodegradable plastic can be degraded 100% for 15 days. Preservation activities show that packaged bananas are still able to survive up to 8 days of post-harvest storage period. These results show the effectiveness of biodegradable plastic preservation of nata de coco-NPZn-moringa leaf extract biodegradable plastic which is quite good.

Physio-chemical analysis and antioxidative response of Ag NPs synthesized by sufaid chonsa mango pulp extracts of different ripening stages

In this study, sufaid chonsa mango pulp aqueous extracts from different ripening stages (RS I-V) was utilized to synthesize silver nanoparticles (Ag NPs). The Ag NPs were characterized using UV-vis spectrometry, X-ray diffraction analysis (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy dispersice X-ray analysis (EDX). Additionally, antioxidative potential and phenolic and flavonoid-like properties of synthesized Ag NPs were also accessed. UV-vis spectrophotometer analysis showed peaks in around 400 nm. XRD analysis confirmed the crystalline structure of the green-synthesized Ag NPs, with sizes ranging from 2.11 to 11.72 nm. FTIR verified the attachment of functional groups from the mango pulp extract to the Ag NPs. SEM analyses revealed that the morphology of the Ag NPs was primarily spherical that were agglomerated. The total antioxidant capacity, measured by the DPPH assay, showed 51% radical scavenging activity for RSIII extract synthesized NPs. The highest total antioxidant capacity was observed to be 80.22 and 79.14 µg AAE/mg NPs by RSI and RSIV synthesized NPs, respectively, while the maximum total reduction potential was 28.67 µg AAE/mg for Ag NPs synthesized by RSII extract. Ag NPs derived from RSIV exhibited phenolic-like property of 70.84 µg GAE/mg, while those derived from RSII had a maximum flavonoid-like property of 35.37 µg QE/mg. This study demonstrates that mango pulp at different ripening stages produces Ag NPs with distinct characteristics, making them suitable for various environmental and biomedical applications.

Isolation and identification of diosgenin and flavonoids compound from ethanol extract of Dioscorea hispida Dennst. tuber

The tuber of Dioscorea hispida Dennst. has potential for development as a synthetic pharmaceutical ingredient due to the presence of secondary metabolites such as diosgenin and flavonoids, which exhibit biological activity within the body. Further exploration of this potential requires the isolation and identification of these compounds. Diosgenin was isolated from the ethanol extract using thin-layer chromatography, while flavonoids were isolated from the ethyl acetate fraction using paper chromatography. The pure isolates of both compounds were identified using UV-Vis spectrophotometry and FT-IR spectroscopy. The UV-Vis spectrophotometric analysis of diosgenin revealed maximum absorption wavelengths at 205 and 453 nm. Flavonoid isolates exhibited maximum absorption wavelengths of 264 nm for the first isolate, 265 nm for the second, 276 nm for the third, and 272 nm for the fourth. FT-IR spectroscopic analysis of the diosgenin isolate indicated the presence of functional groups such as -OH, aromatic C=C, and aromatic C-O, while the flavonoid isolate showed the presence of O-H, aromatic C-H, aliphatic C-H, C=O, C=C, and C-O. These identification results confirm that the isolates obtained indeed contain diosgenin and flavonoids.

Green Synthesis of Iron Oxide NPs (IONPs) by Using Aqueous Extract of Parthenium hysterophorus Linnaeus for the In-vitro Antidiabetic and Anti-inflammatory Activities

The Parthenium hysterophorus Linnaeus is one of the anti-inflammatory and antidiabetic ethnomedicine. Therefore the formulation of this plant as nanoparticles will be fruitful anti-inflammatory and antidiabetic as compared to conventional extract. In the current study, the aqueous kernel extract from Parthenium hysterophorus Linnaeus was subjected to synthesize iron oxide nanoparticles (IONPs) and explored their anti-inflammatory and anti-diabetic potentials. The results indicate that the aqueous kernel extract effectively produced IONPs, which were verified using standard analytical methods. UV-visible spectrophotometer analysis was used to check the formation of IONPs. The Fourier-transform infrared spectroscopy (FTIR) was used to check numerous functional groups from the valuable phytochemicals present in the extract. These functional groups play crucial roles as reducing, capping, and stabilizing agents during the synthesis of IONPs. Additionally, scanning electron microscopy (SEM) were utilized to investigate the surface characteristics of the nanoparticles. Notably, the IONPs fabricated from the extract demonstrated promising anti-inflammatory activity, inhibiting Human RBC by 79% and Heat Induced Hemolysis by 72%, as well as showing anti-diabetic potential with 60% inhibition of yeast glucose uptake and 72% inhibition of α-amylase activity, all at a concentration of 100 μg mL-1. These effects were partly comparable to standard drugs with anti-inflammatory activity of 85% inhibition of Human RBC and 78% inhibition of Heat Induced Hemolysis, and anti-diabetic activity of 67% inhibition of yeast glucose uptake and 78% inhibition of alpha amylase.

Rapid and selective quantitative colourimetric analysis of nitrite in water using a S-Nitrosothiol based method

This study introduces a novel S-nitrosothiol based method for the rapid and highly selective detection of nitrite in complex water matrices. Sodium 3-mercapto-1-propanesulfonate forms a distinctive pink S-nitrosothiol compound upon interaction with nitrite in acidic media, allowing both visual and quantitative detection. Various factors affecting the absorbance of the final product were investigated, including pH, reaction time, acid type, and sodium 3-mercapto-1-propanesulfonate concentration. UV–Vis spectrophotometric analysis demonstrated an excellent linear correlation (R2 = 0.99) across a broad detection range (0.05 to 80 mmol l-1), while showing no interference from common ions such as nitrate or dissolved organic matter, a limitation frequently observed in conventional UV-based nitrite detection methods. The assay was further adapted into a pellet form to simplify field use, operating effectively at room temperature with a low detection limit (1.4 ppm). The S-nitrosothiol based method represents a safer and more environmentally friendly option for nitrite detection and shows a promising potential as a valuable addition to both field and laboratory water testing kits for nitrite analysis.

Development and fabrication of graphene oxide and reduced graphene oxide incorporated MnFe2O4@Bi2WO6 nanocomposite for efficient degradation of antibiotic drug as water contaminant under visible-light illumination

Tetracyclines are one category of extensively applied antibiotics. Meantime, owing to misapplication and inappropriate disposal, they are mostly discovered in wastewater, which causes a series of environmental contamination and stated a threat to a person's health and security. The present study investigates the photodegradation of tetracycline using MnFe2O4@Bi2WO6/graphene oxide, GO, and MnFe2O4@Bi2WO6/reduced graphene oxide, RGO, and MnFe2O4@Bi2WO6 nanocomposites as permanent photocatalyst with the aid of visible light. A facile microwave assisted combustion method was applied in solid state rapidly, conveniently to fabricate MnFe2O4@ Bi2WO6–GO and MnFe2O4@ Bi2WO6–rGO nanocomposites at low power 150 W and in time 10 min with very low amount of glycine (as fuel). Consequently, XRD, EDX Mapping, DRS, PL, TEM, FESEM, FTIR, VSM, BET and UV–Visible spectrophotometric analysis demonstrated characteristic of nanocomposites and specifications of existent photocatalyst. Magnetic investigations revealed that the MnFe2O4@ Bi2WO6-GO and MnFe2O4@ Bi2WO6–RGO nanocomposites can be easily separated from the solution by an external magnetic field. MnFe2O4@ Bi2WO6–GO nanocomposites were discovered with high specific surface area 73.83 m2/g than MnFe2O4@Bi2WO6–RGO nanocomposites with specific surface area 17.75 m2/g. Highest photocatalytic activity was determined for the MnFe2O4@ Bi2WO6–GO (catalyst-0.10 g/l, tetracycline antibiotic concentration 10 mg/l and at pH = 4) within 25 min of visible light irradiation without using any oxidizing agent. The investigation of kinetic study revealed that kinetic parameter specified to photodegradation and experimental outcomes follow first-order model. the superoxide, hydroxyl radicals, ℎ+ holes and light are the principal demonstrates of the reaction mechanism for the effective degradation of tetracycline drug. The evaluation of MnFe2O4@ Bi2WO6–GO and MnFe2O4@ Bi2WO6–RGO magnetic catalysts has proposed the encouraging and significant role of nanocomposites in perilous pharmaceuticals refinement from industrial wastewater and also, magnetically photocatalyst attributes can be used as a potent separable tool for eliminating water pollution problems in the various industry.

Characterization of Bacillus pacificus KUMBNGBT-39-Derived Polyhydroxybutyrate and Impact of Physicochemical Factors on its Production.

The extensive use of various chemicals in synthetic plastics is toxic and threatens the biosphere. To address this, the study aimed to isolate, screen, characterize, optimize, and quantify polyhydroxybutyrate (PHB)-producing bacteria using cost-effective residues. Isolated from a landfill site, the Gram-positive, rod-shaped, spore-forming, motile bacterium with intracellular PHB granules was identified as Bacillus pacificus based on phenotypic and genotypic characteristics. Optimal PHB production parameters included a nutrient broth medium, 72h of incubation, a temperature of 37° C, a pH of 7.0, glucose as the carbon source, ammonium chloride as the nitrogen source, and a carbon-to-nitrogen ratio of 4:1, resulting in a 1.42-fold PHB production increase. B. pacificus was also cultured on various low-cost substrates. Among the oil wastes, feedstock showed the highest PHB production (1.983 ± 0.005g/L) and among agricultural residues, the maximum PHB was obtained from rice bran (1.626 ± 0.01g/L). UV-visible spectrophotometric, FT-IR, and HR-LCMS analysis of extracted PHB confirmed characteristics of PHB molecules (ʎ-max at 210nm, functional groups between 1152 and 2925cm-1). The 1H NMR analysis revealed distinct signals for protons resonating at aliphatic CH3 proton groups, bridged CH protons, and shielding CH2 proton regions that matched PHBs. Thermal gravimetric analysis (TGA) and direct scanning colorimetric (DSC) analysis revealed 89.4% degradation and melting temperature at 124.1°C for the extracted PHB compound.

Sustainable ultrasonic extraction of antibacterial Basella alba fruit dye for cotton, silk, and leather

Alternative to synthetic dyes containing harmful compounds, dyes derived from natural sources are gaining popularity due to their safer and eco-friendly nature. This study focuses on extracting red dye from Basella alba fruit and optimising the extraction methods, including ultrasonic bath, ultrasonic probe, and direct heating. The extracted dye was then used for dyeing cotton, silk, and leather without needing a mordant. Furthermore, the antibacterial properties of the extracted red dye were evaluated against skin bacteria. The UV–Visible spectrophotometric analysis revealed that the maximum red colour in the methanol extract (λmax 270 and λmax 542 nm) was achieved at 60 °C for 30 min using the ultrasonic water bath extraction method, followed by the ultrasonic probe and direct heating methods. The FTIR spectra confirmed the presence of flavonoids, betacyanin, and gomphrenin-I in the extracted dye. The ultrasonic dyeing process at 50 °C yielded a K/s value 6.3 for the dyed cotton, silk, and leather without using a mordant. Additionally, the fatness test indicated a high grade of 0.5–1.5 for the ultrasonic dyeing method compared to other dyeing techniques. The extracted dye exhibited significant antibacterial activity against all Pseudomonas sp. after extraction in methanol, with the highest inhibition observed against Pseudomonas sp. with a MIC of 1.56 mg/ml.

Reactive Condensation of Cr Vapor on Aluminosilicates Containing Alkaline Oxides

This study is part of a series with the objective of improving fundamental understanding of reactive condensation of Chromium (Cr) vapors, which are generated from Cr containing alloys used in many high-temperature (>500 °C) process environments and can form potentially problematic condensed hexavalent (Cr(VI)) species downstream. This study specifically focuses on the effects of alkaline oxide additives in aluminosilicate fibers on Cr condensation and speciation. Cr vapors were generated by flowing high-temperature (800 °C) air containing 3% water vapor over chromia (Cr2O3) powder, with aluminosilicate fiber samples positioned downstream where the temperature decreases (<500 °C). Total condensed Cr and ratios of oxidation states were measured using inductively coupled plasma optical emission spectroscopy (ICP-OES) and diphenyl carbazide (DPC) colorimetric/direct UV–vis spectrophotometric analyses. Results indicate presence of hexavalent Cr (Cr(VI)) species condensed on all samples investigated. The ratio of Cr(VI) to total Cr detected was consistently higher on aluminosilicate fiber samples containing alkaline oxide (CaO and MgO) additions. Computational thermodynamic equilibrium modelling corroborated experimental results showing stabilities of Ca and Mg chromate (Cr(VI)) compounds. Comparative results and analyses are presented and discussed to help inform mechanistic understanding and future related research and engineering efforts.

Investigation of the solubility behavior of emodin and aloe-emodin in water + ethanol mixtures at various temperatures ranging from 283.15 K to 323.15 K

A thermostated reactor and UV–visible spectrophotometer analysis were used to determine the solubility of emodin and aloe-emodin, two naturally occurring compounds with pharmacological activity. At a pressure of 0.1 MPa under atmospheric conditions, and temperatures from 283.15 to 323.15 K with intervals of 5 K, the solubility in different water–ethanol combinations was the primary focus of the investigation. Under constant solvent composition, a positive correlation was observed between the solubility of emodin/ or aleo-emodin and the experimental temperature in all examined mixed solvent systems. To better understand the relationships between solutes and solvents and the interactions between several solvents, the KAT-LSER model was used to conduct multiple linear regression analysis on systems containing either pure solvents or a combination of solvents. In addition, several thermodynamic models were used to establish a connection with the empirical solubility data. These models included the Jouyban-Acree, Apelblat-Jouyban-Acree, van’t Hoff-Jouyban-Acree, and Ma models. The correlation findings demonstrate that all four thermodynamic models accurately predicted emodin and aleo-solubility emodin’s behavior under different solvent and temperature settings. Furthermore, the thermodynamic characteristics of emodin solubility in binary solvent combinations were determined using the van’t Hoff model. According to the findings, two compounds were found to undergo endothermic and non-spontaneous dissolution.

Core-shell V2O5- Gum ghatti grafted poly (acrylamide-co-methacrylic acid) adsorbent for the removal of methylene blue dye in water: Kinetic, equilibrium and thermodynamic studies

Herein, vanadium pentoxide (V2O5) encapsulated Gum ghatti grafted poly(acrylamide-co- methacrylic acid) adsorbent was synthesized to remove methylene blue dye from water. The materials were characterized by FTIR, TEM, SEM, Raman and XRD analysis. Batch adsorption studies were performed on the materials. Several variables' effects on methylene blue removal, including pH, contact time, initial dye concentration, and adsorbent dosage, were examined. Kinetics and thermodynamic analysis were also carried out for the adsorbent-adsorbate interaction to determine the maximum adsorption and mechanism for adsorption. By using UV-Vis spectrophotometric analysis, the dye concentration was evaluated both before and after adsorption. Langmuir, Freundlich, and Dubini-Radushkevic's isotherm models were used to analyze the adsorption data. Results showed a maximum adsorption efficiency of 92 % at a pH of 9 and 0.2 g as the maximum adsorbent dosage. The study followed the Langmuir isotherm model with a correlation coefficient (R2) of 0.9995. The results from the kinetic studies show a pseudo-second-order mechanism. The negative values of the Gibbs free energy change ΔG° ranging from −10.57 KJmol−1 to −9.64 Kmol−1 within the temperatures of 298 K to 313 K is an indication of a spontaneous process. A negative enthalpy change (ΔH° = −29.05 KJmol−1) shows an exothermic process and a negative entropy change (ΔS° = −0.06 KJmol−1) represents a highly ordered system. ANOVA in Microsoft Excel and other statistical analyses were used to evaluate the effects of time, pH, concentration, dose, temperature, and other factors on the effectiveness of dye adsorption. Importantly, every parameter that was investigated showed statistically significant impacts on the removal of dye (p < 0.05), revealing their important impact on the adsorption process.

(Digital Presentation) Reactive Evaporation of Cr Vapors from Chromia-Alkaline Oxide Mixtures Generated in 800℃ Air and Subsequent Condensation Onto Aluminosilicate Fibers

This research aims to improve fundamental understanding of the reactive evaporation and condensation of Chromium (Cr) vapors, which are generated from Cr containing alloys used in many high-temperature (>500℃) process environments and can form potentially problematic condensed hexavalent (Cr(VI)) species downstream. This study focuses on the effects of alkaline oxides present in the Cr source on the resultant Cr evaporation and condensation. Vapor species were generated by flowing high-temperature (800℃) air containing 3% water vapor over chromia (Cr2O3) and mixtures of chromia with calcium oxide (CaO) or magnesium oxide (MgO) powders. Lab-grade quartz and alumina fiber samples were positioned downstream from the Cr-alkaline oxide source where the temperature decreases (<500℃) to collect condensed vapor species. Total condensed Cr and ratios of oxidation states were measured using inductively coupled plasma optical emission spectroscopy (ICP-OES) and diphenyl carbazide (DPC) colorimetric/direct UV-VIS spectrophotometric analyses. Preliminary results indicate a decrease in partial pressures of generated Cr vapor species as well as a decrease in condensed Cr species on the aluminosilicate fibers when alkaline oxides are present in the Cr source compared to a pure Cr source. These results also indicate presence of hexavalent Cr (Cr(VI)) species condensed on all samples investigated. Computational thermodynamic equilibrium modelling corroborated the experimental results showing partial pressures of produced vapor species in the presence of alkaline oxides as well as stabilities of condensed Cr compounds on the fiber samples. Comparative results and analyses are presented and discussed to help inform mechanistic understanding and future related research and engineering efforts. Figure 1

Acute Toxicity, Anti-diabetic, and Anti-cancerous Potential of Trillium Govanianum-conjugated Silver Nanoparticles in Balb/c Mice.

The current study aimed to develop an economic plant-based therapeutic agent to improve the treatment strategies for diseases at the nano-scale because Cancer and Diabetes mellitus are major concerns in developing countries. Therefore, in vitro and in vivo antidiabetic and anti-cancerous activities of Trillium govanianum conjugated silver nanoparticles were assessed. In the current study synthesis of silver nanoparticles using Trillium govanianum and characterization were done using a scanning electron microscope, UV-visible spectrophotometer, and FTIR analysis. The in vitro and in vivo anti-diabetic and anti-cancerous potential (200 mg/kg and 400 mg/kg) were carried out. It was discovered that Balb/c mice did not show any major alterations during observation of acute oral toxicity when administered orally both TGaqu (1000 mg/kg) and TGAgNPs (1000 mg/kg), and results revealed that 1000 mg/kg is not lethal dose as did not find any abnormalities in epidermal and dermal layers when exposed to TGAgNPs. In vitro studies showed that TGAgNPs could not only inhibit alpha-glucosidase and protein kinases but were also potent against the brine shrimp. Though, a significant reduction in blood glucose levels and significant anti-cancerous effects was recorded when alloxan-treated and CCl4-induced mice were treated with TGAgNPs and TGaqu. Both in vivo and in vitro studies revealed that TGaqu and TGAgNPs are not toxic at 200 mg/kg, 400 mg/kg, and 1000 mg/kg doses and possess strong anti-diabetic and anti-cancerous effects due to the presence of phyto-constituents. Further, suggesting that green synthesized silver nanoparticles could be used in pharmaceutical industries to develop potent therapeutic agents.

Green synthesized extracts/Au complex of Phyllospongia lamellosa: Unrevealing the anti-cancer and anti-bacterial potentialities, supported by metabolomics and molecular modeling

The anti-cancer and anti-bacterial potential of the Red Sea sponge Phyllospongia lamellosa in its bulk (crude extracts) and gold nanostructure (loaded on gold nanaoparticles) were investigated. Metabolomics analysis was conducted, and subsequently, molecular modeling studies were conducted to explore and anticipate the P. lamellosa secondary metabolites and their potential target for their various bioactivities. The chloroformic extract (CE) and ethyl acetate extract (EE) of the P. lamellosa predicted to include bioactive lipophilic and moderately polar metabolites, respectively, were used to synthesize gold nanoparticles (AuNPs). The prepared AuNPs were characterized through transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and UV–vis spectrophotometric analyses. The cytotoxic activities were tested against MCF-7, MDB-231, and MCF-10A. Moreover, the anti-bacterial, antifungal, and anti-biofilm activity were assessed. Definite classes of metabolites were identified in CE (terpenoids) and EE (brominated phenyl ethers and sulfated fatty amides). Molecular modeling involving docking and molecular dynamics identified Protein-tyrosine phosphatase 1B (PTP1B) as a potential target for the anti-cancer activities of terpenoids. Moreover, CE exhibited the most powerful activity against breast cancer cell lines, matching our molecular modeling study. On the other hand, only EE was demonstrated to possess powerful anti-bacterial and anti-biofilm activity against Escherichia coli. In conclusion, depending on their bioactive metabolites, P. lamellosa-derived extracts, after being loaded on AuNPs, could be considered anti-cancer, anti-bacterial, and anti-biofilm bioactive products. Future work should be completed to produce drug leads.

Thermal Stability, Transparency, and Water Sensitivity Properties of Bleached, Cross-Linked Cassava Starch Film

This work investigated a novel study of the effect of bleaching and cross-linking cassava starch film. Native cassava starch was bleached with hydrogen peroxide (H2O2), cross-linking was carried out with oxidized sucrose while glycerol was added to enhance the plasticity of the film. Operating temperature and time of 90 oC and 10 Minutes respectively with and addition of 0.5 ml of glycerol gave the best bleached, cross-linked cassava starch film. UV-visible spectrophotometer analysis revealed that the cassava starch film produced at the above reaction conditions retained 88.2 % of its transparency at 96 hours water immersion. The water solubility test shows that the film experienced 52.02 % weight loss after 96 hours immersion in water. The thermo-gravimetric analysis (TGA) shows a significant improvement on the thermal stability with Temperature peak (Tp) of 420.75 oC, compared to 374.13 oC Tp of the control sample (unbleached, uncross-linked) of the cassava starch film.

Antibacterial activity of pigment extracted from bacteria isolated from soil samples

The purpose of this study was to evaluate antibacterial activity of pigment extracted from bacteria, isolated from soil samples. During the study, 20 soil samples were collected from different areas (forest, agriculture fields, river sides and dumping sites) of Kathmandu and Lalitpur districts which were processed for isolation of pigment producing bacteria by spread plate technique. The pigmented bacterial isolates were identified and enriched in nutrient broth. Then, pigment was extracted in 95% methanol as solvent, which was further characterized using UV-Vis Spectrophotometric and TLC analysis. The obtained crude pigment extract was processed to carry out the antimicrobial susceptibility assay using agar well diffusion method. Out of 13 total pigmented bacteria isolates, four different colored pigmented bacterial isolates (S4O, S11Y, S14P and S17G) which produced efficient pigment on nutrient agar were chosen and they were further processed. Among these isolates, S4O was identified as Staphylococcus aureus, S11Y was identified as Micrococcus luteus, S14P was identified as Micrococcus roseus and S17G was identified as Pseudomonas aeruginosa respectively. On characterization using UV-Vis Spectrophotometric and TLC analysis, the pigment extracted from isolates S4O, S11Y and S14P were found to be Carotenoids and from isolate S17G was found to be Pyocyanin in nature. The maximum antibacterial activity was shown against Staphylococcus aureus from all the four pigments extracts. The green color pigment extract from isolate S17G was found to be most effective against all the Gram-positive and Gram-negative test bacteria. This study suggests that these pigment extracts from pigmented bacteria may have beneficial antibacterial roles that can be exploited in controlling unwanted bacterial growth.

Isolation and characterization of Pseudomonas aeruginosa VK30 capable of degradation of Triton X-100

Abstract Triton X-100 is widely used in various industrial and commercial products. The harmful effects of Triton X-100 on aquatic organisms have experimentally been shown. In this study, we isolated twelve bacteria from polluted water and soil samples, demonstrating the ability to utilize Triton X-100 as their exclusive carbon and energy source. Strain VK30, distinguished by its effective Triton X-100 utilization, underwent further investigation and was identified as Pseudomonas aeruginosa through 16S rRNA gene analysis. The degradation of Triton X-100 was validated via UV–Visible spectrophotometric analysis. These findings suggest that strain VK30 can be a promising candidate for remediation of Triton X-100.

Photoelectrode FTO/ Anodized TiO2 Production and Characterization for Methylene Blue Affected Photoelectrochemical Decomposition

Background: The production of thin film TiO2 nanostructured systems for electrocatalytic, photocatalytic, and photoelectrocatalytic applications has been an essential topic in recent years. Due to the light-sensitive effect of TiO2, it can be produced by various methods and used as a photoelectrode to remove dye. Using magnetron sputtering, Ti thin films can be deposited on different substrates and converted into transparent TiO2 structures by electrochemical anodization. Methods: In this study, the thin Ti film was produced using a magnetic spraying technique on the FTO substrate, and then an anodic TiO2 structure was obtained by the anodization technique. TiO2 films produced by the anodizing technique were used as a photoelectrode for the degradation of MB. The reactor contained 400 mL of 20 mg/L MB solution at 20 °C. The produced photoelectrode was characterized by the SEM/EDS, FTIR, XRD, and UV-Vis Spectrophotometer analyses. Results: The EDS analysis confirmed the presence of titanium and oxygen in the FTO/ Anodized TiO2 photoelectrode. The XRD results showed that all the peaks of the produced FTO/ Anodic TiO2 were associated with the anatase phase of TiO2. According to the FTIR spectroscopy, the functional groups of the anodized TiO2 were obtained for the FTO/ Anodized TiO2. The electrocatalytic, photocatalytic, and photoelectrocatalytic degradation experiments were performed with the degradation of the dye solution of MB on the FTO/ Anodic TiO2 photoelectrode, and the rates of dye degradation were determined as 17.12%, 64.67%, and 82.12%, respectively. Conclusion: This study showed that the methylene blue dye of FTO/ Anodic TiO2 is a suitable photoelectrode for electrocatalytic, photocatalytic, and photoelectrocatalytic degradation.

Efficient photocatalytic degradation of profenofos by CuO-ZnO nanocomposite

Exposure to organophosphate pesticides, such as profenofos, poses a serious threat to humans and other living organisms and thus, it needs serious precaution measurements. Herein, we have developed bimetallic nanocomposite CuO-ZnO (2:1 ratio) with two band edges (1.60 eV and 3.1 eV) and two band potentials (1.373 eV and − 0.207 eV) as an appealing heterogeneous photocatalyst for the effective adsorption and photocatalytic degradation of profenofos at an ambient condition. The degradation process occurs rapidly, manifesting within a brief duration under light exposure. Notably, the CuO-ZnO) nanocomposite was directly subjected to the highest profenofos dose (1215 mg/L). Impressively, complete photocatalytic degradation (100 %) was achieved within just 80 min of exposure, emphasizing the efficacy of the photocatalytic process as a degradation/transformation pathway. Furthermore, a proposed degradation/transformation and mineralization pathway for the profenofos pesticide was delineated, based on results obtained from spectroscopic and chromatographic techniques. UV–visible spectrophotometric analysis tracked the degradation and transformation of profenofos (275.5 nm) to 2-chloro-3-bromo phenol (287.2 nm), while its mineralization was confirmed through NMR, ATR-IR, and GC–MS analysis. The explored catalytic activities, and degradation pathway intensely suggested that the hydroxyl radical (HO•) radicals are the central active degradation species produced through the “VB” pathway on the surface of CuO-ZnO nanocomposite.The kinetics models showed that the reaction predominantly follows second-order kinetics. Additionally, thermodynamic parameters, like enthalpy (ΔH), entropy (ΔS) and Gibbs free energy (ΔG) were evaluated, revealing the exothermic and spontaneous nature and of the reaction. Besides, CuO-ZnO nanocomposite possesses the optimal recyclability for up to seven rounds with nominal loss in the degradation efficacy and sustaining its structural features proving its robust nature towards the degradation of profenofos. Additionally, the environmental hazard posed by the profenofos pesticide, and its degradation products was assessed using the Estimation Program Interface (EPI) SuiteTM v.4.11, developed by the US Environmental Protection Agency. The estimation models affirmed that the degradation and transformation products exhibit relatively lower toxicity levels compared to profenofos.