Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 72
Filtrar
1.
Heliyon ; 10(13): e33861, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39071692

RESUMO

In this study, nickel manganite (NiMn2O4) nanoparticles were prepared using a hydrothermal method and examined its potential as a photocatalyst for the Acid Green 25 (AG-25) dye degradation. The nanoparticles were subjected to structural analysis using X-ray diffraction (XRD) and morphological analysis using scanning electron microscopy (SEM). The study examined the kinetics and thermodynamics of degradation processes that are catalyzed by photocatalysis. To ascertain their effect on dye degradation, several parameters, such as catalyst dose, H2O2 concentration, and temperature, were investigated. With a temperature of 315 K in a pseudo-first-order kinetic reaction, a 0.3 M H2O2 concentration, 0.05 mg/mL catalyst dose, and a promising removal efficiency of 96 % was achieved by the NiMn2O4 NPs in 40 min. Thermodynamic analysis revealed the spontaneous and entropy-driven nature of catalytic degradation, progressing favorably at elevated temperatures. Additionally, the NiMn2O4 NPs were applied as a fuel additive to analyze its influence on combustion and the physical characteristics of the modified fuel. The modified fuel demonstrated exceptional catalytic efficiency, emphasizing the potential of the NiMn2O4 NPs as an effective additive.

2.
Heliyon ; 10(10): e30927, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38779003

RESUMO

The purpose of this study was to synthesize ecofriendly nano-composite in which agricultural waste (seeds of Tamarindus indica) was used to synthesize tamarind seed polysaccharides (TSP) and its composite with copper nanoparticles (Cu-NPs) for the purpose of green and clean environment as well as reduction of green-house gases. Confirmation of extracted TSP, synthesized nanocomposite was carried out using FTIR, SEM, PXRD and EDX techniques. In FTIR analysis TSP gives a strong broad peak at 3331 cm-1 due to -OH group and in case of composite its intensity is reduced which might be due to the interactions between -OH and Cu+2 ions. SEM analysis gives that TSP have irregular and rough surface while Cu-NPs exhibited spherical morphology and composite showed clustering of spherical shape to rough surface. EDX analysis quantitatively represented copper having atomic ratio 0.57 % which confirms the synthesis of composite. Furthermore, synthesized composite demonstrated excellent antibacterial activity against gram-positive (S.aureus) and gram-negative bacteria (E.coli) even greater than standard medicine (ciprofloxacin). From this study it was revealed that agriculture waste can be utilized to make environment green as well as synthesized composite from agricultural waste seed also displayed excellent antimicrobial activities which directs that they can be utilized in medical field. This study aims to assess the antimicrobial properties of the nanocomposite, aiming to contribute to the development of effective antimicrobial agents. Through these objectives, the research seeks to bridge the gap between green technology and antimicrobial efficacy, offering a promising avenue for both environmental conservation and healthcare advancements.

3.
Int J Biol Macromol ; 261(Pt 2): 129881, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38316323

RESUMO

Photocatalysis is a clean and efficient process pursued under light irradiation with a suitable photocatalyst to degrade a contaminant. We report citrate functionalization of silver nanoparticles (SNPs) for effective immobilization on cellulosic fabric. The porous cellulosic matrix could be explored as microfiltration membranes for the photocatalytic degradation of organic dyes in the aqueous media. Where valid, the citrate functionalized SNPs and the treated cellulose fabrics were considered for optical, structural, surface chemical, thermal, textile, flowability, photocatalytic, and antibacterial attributes. The SNPs expressed the bandgap energy of 2.56 and 2.43 eV and Urbach energy of 3.38 and 5.21 eV before and after functionalization with the citrate moieties, respectively. The liquid chromatographic and FTIR analyses indicated that the crystal violet (CV) organic dye has been successfully photodegraded to environmentally safer and nontoxic species on passing the contaminated water through the SNPs-treated cellulosic filter. The spectroscopic data also supported the said outcomes. The results demonstrated that the citrate-SNPs-treated cellulose could be efficiently employed as antibacterial photocatalytic membranes for degrading organic dyes in the aqueous media for multiple cycles.


Assuntos
Ácido Cítrico , Nanopartículas Metálicas , Prata , Citratos , Antibacterianos/farmacologia , Celulose , Corantes
4.
J Mol Graph Model ; 127: 108699, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38150839

RESUMO

Improving the light-harvesting efficiency and boosting open circuit voltage are crucial challenges for enhancing the efficiency of organic solar cells. This work introduces seven new molecules (SA1-SA7) to upgrade the optoelectronic and photovoltaic properties of Q-C-F molecule-based solar cells. All recently designed molecules have the same alkyl-substituted Quinoxaline core and CPDT donor but vary in the end-capped acceptor subunits. All the investigated molecules have revealed superior properties than the model (R) by having absorbance ranging from 681 nm to 782 nm in the gaseous medium while 726 nm-861 nm in chloroform solvent, with the lowest band gap ranging from 1.91 to 2.19 eV SA1 molecule demonstrated the highest λmax (861 nm) in chloroform solvent and the lowest band gap (1.91 eV). SA2 molecule has manifested highest dipole moment (4.5089 D), lower exciton binding energy in gaseous (0.33 eV) and chloroform solvent (0.47 eV), and lower charge mobility of hole (0.0077693) and electron (0.0042470). At the same time, SA7 showed the highest open circuit voltage (1.56 eV) and fill factor (0.9166) due to solid electron-pulling acceptor moieties. From these supportive outcomes, it is inferred that our computationally investigated molecules may be promising candidates to be used in advanced versions of OSCs in the upcoming period.


Assuntos
Clorofórmio , Quinoxalinas , Elétrons , Gases , Solventes
5.
Comput Biol Chem ; 107: 107963, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37776812

RESUMO

N-heterocyclic carbene (NHC) based compounds are remarkably known for astonishing biological potentials. Coordination of metal center with these compounds can substantially improve the biological potential for better efficacy. In this context, three binuclear azolium salts (L1-L3) and subsequent selenium adducts L1Se-L3Se were synthesized and assured through analytical techniques. Synthesized compounds were also simulated through computational approach and results were compared with experimental observations that also relatable with biological potentials. Synthesized compounds were screened against bacterial strains and interestingly, the studied compounds showed good antimicrobial potential with MIC values of 7.01, 10.7 and 10.5 µM for S. Aureus (gram positive bacteria) while 12.5, 11.75 and 14.5 µM against E. Coli (gram negative bacteria). The studied compounds showed good antioxidant activity to scavenge DPPH free radicals among which azolium salts were found better in antioxidant potential (IC50 5.75-6.55 µg/mL) than their respective selenium compounds (IC50 9.50-12.75 µg/mL). The hemolytic assay against red blood cells showed that ligands are least toxic comparative to their Se-adducts and can be further trialed for In Vivo studies.


Assuntos
Compostos Heterocíclicos , Compostos Organosselênicos , Antibacterianos/farmacologia , Antibacterianos/química , Compostos Organosselênicos/farmacologia , Escherichia coli , Staphylococcus aureus , Sais , Compostos Heterocíclicos/farmacologia , Compostos Heterocíclicos/química , Testes de Sensibilidade Microbiana
6.
ACS Omega ; 8(34): 30868-30878, 2023 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-37663520

RESUMO

The present study was designed to synthesize an oval-shaped bimetallic bismuth aluminate (Bi2Al4O9) nanoparticles through a solvothermal approach. The resulting structure and morphology of synthesized materials were characterized through X-ray diffraction and scanning electron microscopy. The catalytic performance of Bi2Al4O9 was investigated using acid green 25 (AG-25) as the model dye. The effect of various parameters like catalyst dose, H2O2 concentration, and temperature on dye degradation was studied. The Bi2Al4O9 nanocomposite exhibited the maximum removal of 95% within 50 min at 0.3 M H2O2 concentration, 0.05 mg/mL catalyst dose, and 315 K temperature. The photocatalytic removal of AG-25 followed pseudo-first-order kinetics. The thermodynamics study exposed that thermal catalytic degradation is a spontaneous, endothermic, as well as entropy-driven reaction that moves in the forward direction at the higher temperatures. The Bi2Al4O9 composite was further applied as fuel additives in order to study combustion and physical characteristics of the modified fuel. The efficacy of modified fuel was studied by investigating the fuel parameters at different Bi2Al4O9 dosages. Results revealed that synthesized NPs are excellent photocatalysts and could possibly be used for the removal of toxic pollutants.

7.
Curr Org Synth ; 2023 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-37622716

RESUMO

BACKGROUND: Azolium salts are the organic salts used as stable precursors for generating N-Heterocyclic Carbenes and their metal complexes. Azolium salts have also been reported to have significant biological potential. Hence, in the current study, four tetra-dentate azolium salts were derived from bis-azolium salts by a new synthetic strategy. METHODS: The tetra azolium salts have been synthesized by reacting the imidazole or methyl imidazole with dibromo xylene (meta, para)/ 1-bromo methyl imidazole or dibromo ethane resulting in the mono or bis azolium salts namely I-IV. V-VII have been obtained by reacting I with II-IV, resulting in the tetra azolium salts. Each product was analyzed by various analytical techniques, i.e., microanalysis, FT-IR, and NMR (1H & 13C). Salts V-VII were evaluated for their antiproliferative effect against human colon cancer cells (HCT-116) using MTT assay. RESULTS: Four chemical shifts for acidic protons between 8.5-9.5 δ ppm in 1H NMR and resonance of respective carbons around 136-146 δ ppm in 13C NMR indicated the successful synthesis of tetra azolium salts. Salt V showed the highest IC50 value, 24.8 µM among all synthesized compounds. CONCLUSION: Tetra-azolium salts may play a better cytotoxicity effect compared to mono-, bi-& tri-azolium salts.

8.
Photodiagnosis Photodyn Ther ; 42: 103607, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37220841

RESUMO

Background The prognosis for oral cancer patients is still very poor worldwide. Early detection and treatment therapy remain the key issue to be addressed for improved patient survival. The characteristic Raman spectral features associated with the biochemical changes in the blood serum samples can be used for the diagnosis of diseases, particularly for oral cancer. Surface-enhanced Raman spectroscopy (SERS) is a promising technique for non-invasive and early detection of oral cancer by analyzing molecular changes in body fluids. Objectives To detect oral cavity anatomical subsites (buccal mucosa, cheek, hard palate, lips, mandible, maxilla, tongue and tonsillar region) cancers by using blood serum samples, SERS with principal component analysis is used. Material and Method SERS is employed with silver nanoparticles for the analysis and detection of oral cancer serum samples by comparing with healthy serum samples. SERS spectra are recorded by Raman instrument and preprocessed using the statistical tool. Principal component analysis (PCA) and Partial least square discriminant analysis (PLS-DA) are used to discriminate between oral cancer serum samples and control serum samples. Results Some major SERS peaks are observed at 1136 cm-1 (Phospholipids) and 1006 cm-1 (Phenylalanine) remain higher in intensities for oral cancer spectra as compared to healthy spectra. The peak at 1241 cm-1 (amide III) is observed only in oral cancer serum samples while absent in healthy serum samples. Higher protein and DNA contents were detected in SERS mean spectra of oral cancer. Moreover, PCA is used to identify the biochemical differences in the form of SERS features which is used to differentiate between oral cancer and healthy blood serum samples, while PLS-DA is used to build differentiation model of oral cancer serum samples and healthy control serum samples. PLS-DA provides successful differentiation with 94% specificity and 95.5% sensitivity. Conclusions SERS can be used for the diagnosis of oral cancer and to identify metabolic changes that occur during disease development.


Assuntos
Nanopartículas Metálicas , Neoplasias Bucais , Fotoquimioterapia , Humanos , Análise Espectral Raman/métodos , Nanopartículas Metálicas/química , Prata/química , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes , Neoplasias Bucais/diagnóstico , Lábio , Análise de Componente Principal
9.
Dalton Trans ; 52(19): 6343-6359, 2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37083039

RESUMO

Solar photocatalysis has emerged as a pollution-free and inexhaustible technique that has been extensively researched in the domains of environmental remediation and energy production. Herein, we have integrated ZnO and CdS nanoparticles through Cu as a solid-state electron mediator to design a ZnO-Cu-CdS Z-scheme heterosystem via a sol-gel route and further tested this as a photocatalyst for dye degradation, H2 evolution, and CO2 reduction. Within 60 min of visible light exposure, about 97% of methylene blue (MB) is degraded with a degradation rate constant of 0.042 min-1 for the ZnO0.45Cu0.1CdS0.45 catalyst. The MB degradation with this catalyst is 84, 21, 4.8, and 2 times as high as those of ZnO, CdS, ZnO0.5CdS0.5, and Cu0.1ZnO0.9 catalysts. The ZnO-Cu-CdS catalyst manifests an H2 evolution efficiency of 5579 µmol h-1 g-1, which is 169, 41, 3.9, and 3.5 times as high as those of ZnO, CdS, ZnO0.5CdS0.5, and Cu0.1ZnO0.9 catalysts. Using H2 as a reducing agent, the CO production rate over the ZnO0.45Cu0.1CdS0.45 catalyst reaches 770 µmol h-1 g-1, which is 3 and 1.8 times higher than those of ZnO0.5CdS0.5 and Cu0.1ZnO0.9 catalysts. Besides, the optimal CH4 production rate over ZnO0.45Cu0.1CdS0.45 reaches 890 µmol h-1 g-1. The improved photocatalytic response of the ZnO-Cu-CdS catalyst is assigned to the delayed recombination of photoexcited charge carriers through a Z-scheme charge transport mode, maintaining the photocarriers with strong redox potentials and the dual role of Cu to serve as a conductive bridge to accelerate the charge transfer rate and enhance the light absorption due to its SPR phenomenon. This research offers a promising strategy for developing binary/ternary Z-scheme heterojunction photocatalytic systems for different photocatalytic applications.

10.
Bioprocess Biosyst Eng ; 46(3): 453-465, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36454313

RESUMO

Dye-contaminated wastewater discharge from textile and dye manufacturing industries is reported as a world worse water polluter due to the toxic and mutagenic behavior of dyes. Peroxidase, one of the key enzymes of oxidoreductases, is widely distributed in nature and has been currently exploited in industries for various applications. Widespread applications of peroxidases are associated with their nonspecific nature towards a wide spectrum of substrates such as phenols, aromatic amines, pesticides, antibiotics, and synthetic dyes. The present study explored the potential of ammonium sulfate precipitated partially purified Brassica oleracea L. var. botrytis leaves peroxidase for degradation of reactive textile dyes Remazol Turquoise Blue 133 G and Drim Red CL4BN. Various physico-chemical parameters such as pH (2-9), temperature (20-70 â„ƒ), enzyme activity (3-24 U/mL), concentrations of H2O2 (0.4-1.4 Mm) and dye (10-100 mg/L) were optimized for enzymatic decolorization of both dyes' solution. Studies revealed that maximum degradation (95%) of Remazol Turquoise Blue 133 G with peroxidase was achieved with 25 mg/L of initial dye concentration, in the presence of 0.8 mM hydrogen peroxide with 45 min of incubation time, at pH 3, 4, and 5, and 70 °C. Maximal decolorization (97%) of Drim Red CL4BN was obtained at pH 2.0, in 10 min of incubation time at 45 â„ƒ using o-dianisidine hydrochloride as a redox mediator. In conclusion, the findings illustrate the prospect of Brassica oleracea peroxidase to remediate dye pollutants and dye-based industrial effluents in a green technology theme.


Assuntos
Brassica , Peroxidase , Botrytis/metabolismo , Peróxido de Hidrogênio , Peroxidases/metabolismo , Corantes/metabolismo , Indústria Têxtil , Têxteis , Folhas de Planta/metabolismo , Biodegradação Ambiental
11.
Bioprocess Biosyst Eng ; 46(3): 443-452, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36318335

RESUMO

One of the big environmental problems in today's world is dye-contaminated toxic waste. Peroxidase is known as highly efficient for the degradation of various pollutants, including dyes. Environmental contamination caused by the discharge of dyes into water bodies is an onerous challenge that poses both human and ecological hazards. In the current studies, biocatalysts used for enzyme decolorization (1847 Colafx Blue P3R and 621 Colafx Blue) are regarded as an eco-friendly method utilizing commonly available low-cost material lemon peels (Citrus limon peroxidase). Peroxidase was extracted in a phosphate buffer of pH 7.0 and partially purified by 20-80% ammonium sulfate precipitation technique from Citrus limon peels. The soluble enzyme was characterized in terms of kinetic and thermodynamic parameters. The values of Km and Vmax (23.16 and 204.08 µmol/ml/min) were determined, respectively. The enzyme showed maximum activity at pH 5.0 and a temperature of 55 °C. Citrus limon efficiently degraded 1847 Colafx Blue P3R and 621 Colafx Blue R dyes with maximum degradation of 83 and 99%, respectively, with an initial dye concentration of 200 ppm at pH 4 and 35 °C temperature within 5-10 min of incubation time. The effect of the redox mediator on the degradation process was examined. Results showed that the peroxidase HOBT system efficiently enhanced the degradation of dyes from water. Hence, Citrus limon peroxidase is an efficient biocatalyst for the treatment of effluents.


Assuntos
Citrus , Corantes , Peroxidase , Poluentes Químicos da Água , Biodegradação Ambiental , Corantes/química , Peroxidases/química , Poluentes Químicos da Água/química
12.
Chemosphere ; 312(Pt 1): 137095, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36334735

RESUMO

In present study, we describe the biodegradation of direct blue (DB) 297 and reactive blue (RB) 221 by immobilizing horseradish peroxidase (HRP) isolated from fresh leaves of Moringa Oliefera on iron oxide nanoparticles. Iron oxide nanoparticles were synthesized by co-precipitation method and showed a maximum immobilization efficiency of 87%. The surface topography of iron oxide nanoparticles was envisaged by scanning electron microscopy (SEM), results showed that magnetic nanoparticles (MNPs) were in the form of aggregates having size of 1 µm. Furthermore, immobilization was confirmed via functional group identification performed by Fourier transformed infrared spectroscopy (FTIR). Immobilization phenomena displaced the optimum temperature from 35 °C to 50 °C moreover, pH optima were altered from 5.0 to 7.0. Vmax and Km for free and immobilized HRP, were 303 U/mg and 1.66 mM and 312 U/mg and 1.94 mM, respectively. Enzymatic thermodynamic measurements (ΔH*, ΔS*, Ea, ΔG*) were also evaluated for immobilized HRP and its free counterpart. Optimum degradation of reactive blue (RB) and direct blue (DB) 297 with free and immobilized HRP was observed at pH 5 and at temperature 40 °C respectively. The removal efficiency of DB 297 and RB 221 with free HRP was 75% and 86% while with immobilized HRP was 81% and 92% respectively. Furthermore, biodegradation of reactive blue (RB) 221 and direct blue (DB) 297 with immobilized and free biocatalyst was also investigated by Fourier transform infrared spectroscopy (FTIR) by identification of groups involved in dye degradation. FTIR results confirmed the 100% degradation of dyes. Immobilized HRP retained significant catalytic activity after five consecutive cycles of dye degradation. In conclusion, Fe3O4 nanoparticles are promising and environmentally friendly media for enzyme immobilization. Moreover, immobilized HRP showed more thermal stability, pH stability and higher dye degradation efficiency as compared to free HRP. Furthermore, the immobilized HRP, economically more convenient and easily removable from reaction media. Owing to its thermal stability, ease of separation from reaction media and reusability, the magnetically separatable immobilized HRP can be exploited successfully for treatment of dye contaminated textile effluents.


Assuntos
Corantes , Enzimas Imobilizadas , Biocatálise , Corantes/química , Estabilidade Enzimática , Enzimas Imobilizadas/química , Peroxidase do Rábano Silvestre/metabolismo , Concentração de Íons de Hidrogênio , Nanopartículas Magnéticas de Óxido de Ferro , Temperatura , Termodinâmica
13.
RSC Adv ; 12(5): 2873-2887, 2022 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-35425316

RESUMO

Anticancer-drug delivery is now becoming a challenging approach for researchers as it allows controlled drug delivery near cancerous cells with minimized generic collection and the avoidance of secondary side effects. Hence in this work, the applications of nanostructures as anticancer drug-delivery carriers were widely investigated to target cancerous tissues. Based on DFT calculations, we investigated the transition metal-doped boron nitride nanostructure as a drug-delivery agent for the gemcitabine drug utilizing the B3LYP/6-31G (d, p) level of theory. In this research, the adsorption energy and electronic parameters of gemcitabine on the interaction with the metal-doped BN nanostructures were studied. It has been observed that metal doping significantly enhances the drug-delivery properties of BN nanostructures. Among the investigated nanostructures, Ni-BN has been found to be the most prominent nanostructure to transport gemcitabine with an elevated value of adsorption energy in both the gas phase (-45.79) and water media (-32.46). The interaction between gemcitabine and BN nanostructures was confirmed through frontier molecular orbitals and stabilization energy analysis. The fractional charge transfer, MEP, NCI, and NBO analyses exposed the charge transfer from drug molecule to the BN nanostructures. Transition density maps and UV-VIS spectra were also plotted to investigate the excited-state properties of the designed complexes. Thus, the present study provides an in-depth interaction mechanism of the gemcitabine drug with BN, which reveals that metal-doped BN nanostructures can be a favorable drug-delivery vehicle for the gemcitabine anticancer drug.

14.
Int J Biol Macromol ; 209(Pt A): 576-585, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35405153

RESUMO

Cellulose/clay/sodium alginate composites were prepared and employed for the removal of methylene blue (MB) dye. Cellulose was extracted from a paper mill waste and used for composite preparation with sodium alginate (Na-Alg) and clay. MB dye removal was analyzed at different operating conditions (pH, initial concentration, temperature, composite dose). The dye was adsorbed up to 90% for an equilibrium time of 60 min at optimum level of adsorbent dose (0.05 g), temperature (30 °C) and pH (i.e., 7 and 11 for cellulose-Na-Alg and cellulose-Na-Alg-clay, respectively). Kinetics and isotherms of MB adsorption were quantified and modeled. Results showed that MB dye adsorption data followed the pseudo-first order kinetics and a statistical physics model was used to analyze the adsorption mechanism. Thermodynamic calculation revealed that the MB dye adsorption on these composites was an exothermic, spontaneous and feasible process. The composites were regenerated with HCl thus contributing to their reutilization in subsequent adsorption cycles. The DFT (density functional theory) calculations were executed to explain the interactions responsible for the adsorption of MB dye on the composites. Results revealed that the Na-Alg-cellulose composites were effective for the MB dye removal. Therefore, these composites can be considered as low-cost alternative adsorbents for the pollution remediation caused by dyes in industrial effluents.


Assuntos
Azul de Metileno , Poluentes Químicos da Água , Adsorção , Alginatos , Celulose , Argila , Corantes , Concentração de Íons de Hidrogênio , Cinética
15.
Chemosphere ; 291(Pt 2): 132796, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34774614

RESUMO

Novel eco-friendly and economically favourable chemically modified biosorbents and biosomposites from sugarcane bagasse (SB) has been investigated for the first time for efficient removal of Acid red 1 dye from wastewater. As fabricated biosorbents and biocomposites were characterized analytically. Batch adsorption experiments has been performed to optimize operating parameters and the determined optimum conditions are; pH: 2, dose: 0.05 g, contact time: between 60 and 75 min, initial dye concentration: 400 mg L-1, and temperature: 30 °C, at which maximum Acid red 1 dye removal capacities were found (within range of 143.4-205.1 mg g-1) by as-designed SB-derived chemically modified biosorbents and biocomposites. This high adsorption capacity was accompanied due to its large specific surface area (30.19 m2 g-1) and excessive functional active binding sites. In terms of the nature of adsorption process, kinetic and isothermal studies demonstrated that experimental data shows greater fitness with pseudo 2nd order and Langmuir model. Thermodynamics analysis revealed that the adsorption process is spontaneous, feasible, and exothermic in nature. Adsorption selective studies signifies that lower concentration of co-existing metallic ions were not interfered during the removal of Acid red 1 dye, which confirms that under optimized adsorption conditions the biosorbents and biocomposites exhibited greater affinity for dye molecules. The excessive quantity (82%) of loaded dye molecules within the adsorbents were extracted within the NaOH eluting media which predicts that as designed biocomposites could have capability of reusability. Hence, it is anticipated that this type of novel SB-derived biocomposites could be considered as greener potential candidate material for commercial scale dye removal applications from industrial wastewater.


Assuntos
Saccharum , Poluentes Químicos da Água , Adsorção , Celulose , Concentração de Íons de Hidrogênio , Cinética , Rodaminas , Termodinâmica , Poluentes Químicos da Água/análise
16.
Biotechnol Appl Biochem ; 69(2): 410-419, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33559904

RESUMO

Microbial lipases hold a prominent position in biocatalysis by their capability to mediate reactions in aqueous and nonaqueous media. Herein, a lipase from Penicillium fellutanum was biochemically characterized and investigated its potential to degrade poly (ɛ-caprolactone) (PCL). The lipase exhibited stability over a broad pH spectrum and performed best at pH 8.5 and 45 °C. The activation energy was determined to be 66.37 kJ/mol by Arrhenius plot, whereas Km and Vmax for pNPP hydrolysis were 0.75 mM and 83.33 µmol/mL/Min, respectively. A rise in temperature reduced the Gibbs free energy, whereas the enthalpy of thermal unfolding (∆H*) remains the same up to 54 °C following a modest decline at 61 °C. The entropy (∆S*) of the enzyme demonstrated an increasing trend up to 54 °C and dropped at 61 °C. Lipase retained stability by incubation with various industrially relevant organic solvents (benzene, hexanol, ether, and acetone). However, exposure to urea and guanidine hydrochloride influenced its catalytic activity to different extents. Under optimal operating conditions, lipase catalyzed the excellent degradation of PCL film degradation leading to 66% weight loss, increased surface erosion, and crystallinity. Fourier-transform infrared spectrometry, differential scanning calorimetry, and scanning electron microscopy studies monitored the weight loss after enzymatic hydrolysis. The findings indicate that P. fellutanum lipase would be a prospective biocatalytic system for polyesters depolymerization and environmental remediation.


Assuntos
Lipase , Poliésteres , Caproatos , Humanos , Lactonas , Lipase/química , Penicillium , Poliésteres/metabolismo , Estudos Prospectivos , Termodinâmica , Redução de Peso
17.
Materials (Basel) ; 14(19)2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34640238

RESUMO

Various conventional approaches have been reported for the synthesis of nanomaterials without optimizing the role of synthesis parameters. The unoptimized studies not only raise the process cost but also complicate the physicochemical characteristics of the nanostructures. The liquid-plasma reduction with optimized synthesis parameters is an environmentally friendly and low-cost technique for the synthesis of a range of nanomaterials. This work is focused on the statistically optimized production of silver nanoparticles (AgNPs) by using a liquid-plasma reduction process sustained with an argon plasma jet. A simplex centroid design (SCD) was made in Minitab statistical package to optimize the combined effect of stabilizers on the structural growth and UV absorbance of AgNPs. Different combinations of glucose, fructose, sucrose and lactose stabilizers were tested at five different levels (-2, -1, 0, 1, 2) in SCD. The effect of individual and mixed stabilizers on AgNPs growth parameters was assumed significant when p-value in SCD is less than 0.05. A surface plasmon resonance band was fixed at 302 nm after SCD optimization of UV results. A bond stretching at 1633 cm-1 in FTIR spectra was assigned to C=O, which slightly shifts towards a larger wavelength in the presence of saccharides in the solution. The presence of FCC structured AgNPs with an average size of 15 nm was confirmed from XRD and EDX spectra under optimized conditions. The antibacterial activity of these nanoparticles was checked against Staphylococcus aureus and Escherichia coli strains by adopting the shake flask method. The antibacterial study revealed the slightly better performance of AgNPs against Staph. aureus strain than Escherichia coli.

18.
Environ Sci Pollut Res Int ; 28(4): 4216-4228, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32936407

RESUMO

8∑PAHs in 2- and 4-month-old desi chicken organs collected from Faisalabad district, Punjab, Pakistan, were examined via high-performance liquid chromatography (HPLC). Exposure doses (AVDD) of PAHs with consequential lifetime excess cancer risks (LtECR) were also estimated in people ingesting laboratory barbecued (Lb) and commercially barbecued (Cb) desi meat organs. The results exposed the presence of 8ΣPAH in 2- and 4-month-old Lb and Cb chicken organs: drumsticks (Ds), breast (BS), and wings (Ws) (0.45, 3.10, 0.97 ng g-1; 2.52, 4.31, 1.22 ng g-1; and 10.09, 15.04, and 9.06 ng g-1 respectively). BαP was found only in Cb organs with the highest concentrations (5.08 ng g-1) in Bs. It was above the EU's tolerable limit, while it was not detected in all Lb organs. The lowest level of 8ΣPAH was found in 2-month-old desi Ws. A comparative percentage increase in 8ΣPAH levels between all Lb and Cb organs was found in the range of 1500-2416.67%. LtECR for males and adults were ranging from 1.35 × E-13 to 4.49 × E-5 at different consumption rates with AVDD ranging from 1.08 E-6 to 6.01 E-5. In contrast to 2- and 4- month-old chicken meat, 2-month-old desi meat is better having less PAH load. Comparing different organs, Ws of former one displayed abridged PAH levels. In conclusion, Lb desi meat is less carcinogenic relative to Cb. More PAH levels are due to secondary smoke in Cb samples collected from the metropolitan. Ingestion of Lb 2-month-old desi chicken organs could be safe to dine as compared with 4-month-old desi and Cb organs. Graphical abstract.


Assuntos
Neoplasias , Hidrocarbonetos Policíclicos Aromáticos , Adulto , Animais , Galinhas , Ingestão de Alimentos , Monitoramento Ambiental , Humanos , Lactente , Laboratórios , Masculino , Paquistão , Hidrocarbonetos Policíclicos Aromáticos/análise , Medição de Risco
19.
Z Naturforsch C J Biosci ; 75(9-10): 369-376, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32589611

RESUMO

Two meta-xylyl linked tetrakis-benzimidazolium salts (L1-L2) as multidentate ligands and two respective silver complexes (C1 and C2) were synthesized. A multistep reaction was done at room temperature, starting with simple benzimidazole and alkyl halides, going through precursors and salt formation by reflux and finally in situ deprotonation of tetrabenzimidazolium salts with Ag2O to yield respective tetra-nuclear Ag(I)-N-heterocyclic Carbene (NHC) complexes. Propyl and butyl groups were bonded at the terminal positions of tetra-azolium open chain salts. Characterization of compounds was done by analytical and spectroscopic techniques. On the basis of spectroscopic data, a chemical structure with open chains having four Ag(I) ions sandwiched between NHC layers was established. Potential of synthesized complexes (C1 & C2) for wound contraction was evaluated and compared with standard wound contraction gel. Percentage wound contraction of both complexes was found very close to that of standard drug used in parallel.


Assuntos
Benzimidazóis/síntese química , Prata/química , Cicatrização/efeitos dos fármacos , Animais , Benzimidazóis/administração & dosagem , Benzimidazóis/química , Benzimidazóis/farmacologia , Modelos Animais de Doenças , Compostos Heterocíclicos/administração & dosagem , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacologia , Estrutura Molecular , Coelhos , Relação Estrutura-Atividade
20.
Int J Biol Macromol ; 153: 146-157, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32114168

RESUMO

The biocomposites of polypyrrole (PPY), polyaniline (PANI) and sodium alginate (NaAlg) with cellulosic biomass barley husk (BH) were prepared and employed for the removal of 2,4-dichlorophenol (2,4-DCP) form aqueous media. The sorption of 2,4-DCP was studied using native and biocomposites (PPY/BH, PANI/BH and NaAlg/BH) as function of various process variables. The maximum sorption (qe, 7.55-24.57 mg/g) of 2,4-DCP was achieved in the range of 7-10 pH, 0.05 g composite dose, 25 mg/L initial concentration of 2,4-DCP and 120 min contact time at 30 °C. The FTIR analysis revealed the involvement of amino, hydroxyl and carboxylic groups for the binding of 2,4-DCP on the surface of biocomposites. The Freundlich and pseudo second order kinetics models best explained the 2,4-DCP adsorption on to the biocomposites. The ∆G, ∆H and ∆S parameters were also computed, which revealed the favorable and exothermic adsorption nature of 2,4-DCP. Presence of salts affected the 2,4-DCP adsorption negatively. HCl found to be efficient desorbing agent for 2,4-DCP from composites and up to 65.12% was eluted using 0.5 N solution. In view of promising efficiency, the biocomposites have potential to remove 2,4-DCP form industrial effluents.


Assuntos
Alginatos/química , Compostos de Anilina/química , Biomassa , Celulose/química , Clorofenóis/isolamento & purificação , Polímeros/química , Pirróis/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água , Clorofenóis/química , Poluentes Químicos da Água/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA