Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 69
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
3.
Glob Chall ; 7(12): 2300118, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38094862

RESUMO

Various concentrations of samarium-grafted-carbon nitride (Sm-g-C3N4) doped-bismuth oxobromide (BiOBr) quantum dots (QDs) are prepared by the co-precipitation method. Elemental evaluation, morphological, optical, and functional group assessment are studied employing characterization techniques. Based on the XRD pattern analysis, it is determined that BiOBr exhibits a tetragonal crystal structure. The electronic spectroscopy revealed an absorption peak for BiOBr at 315 nm and the bandgap energy (E g) decreasing from 3.9 to 3.8 eV with the insertion of Sm-g-C3N4. The presence of vibrational modes related to BiOBr at 550 cm-1 is confirmed through FTIR spectra. TEM revealed that pure BiOBr possessed non-uniform QDS, and agglomeration increased with the addition of Sm-g-C3N4. The catalytic performance of Sm-g-C3N4 into BiOBr (6 mL) in a neutral medium toward rhodamine B exhibited excellent results (99.66%). The bactericidal activity is evaluated against multi-drug resistance (MDR) Escherichia coli once the surface area is increased by dopant and the measured inhibition zone is assessed to be 3.65 mm. Molecular docking results supported the in vitro bactericidal potential of Sm-g-C3N4 and Sm-g-C3N4 doped-BiOBr as DNA gyraseE. coli inhibitors. This study shows that the novel Sm-g-C3N4 doped-BiOBr is a better catalyst that increases specific semiconductor's catalytic activity (CA).

4.
Sci Rep ; 13(1): 17847, 2023 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-37857696

RESUMO

The environmental-friendly hydrothermal method has been carried out to synthesize Bi2WO6 and g-C3N4/PVP doped Bi2WO6 nanorods (NRs) by incorporating different concentrations of graphitic carbon nitride (g-C3N4) as well as a specified quantity of polyvinylpyrrolidone (PVP). Bi2WO6 doped with g-C3N4 provides structural and chemical stability, reduces charge carriers, degrades dyes, and, owing to lower bandgap energy, is effective for antibacterial, catalytic activity, and molecular docking analysis. The purpose of this research is the treatment of polluted water and to investigate the bactericidal behavior of a ternary system. The catalytic degradation was performed to remove the harmful rhodamine B (RhB) dye using NaBH4 in conjunction with prepared NRs. The specimen compound demonstrated antibacterial activity against Escherichia coli (E. coli) at both high and low concentrations. Higher doped specimens of g-C3N4/PVP-doped Bi2WO6 exhibited a significant improvement in efficient bactericidal potential against E. coli (4.55 mm inhibition zone). In silico experiments were carried out on enoyl-[acylcarrier-protein] reductase (FabI) and ß-lactamase enzyme for E. coli to assess the potential of Bi2WO6, PVP doped Bi2WO6, and g-C3N4/PVP-doped Bi2WO6 NRs as their inhibitors and to justify their possible mechanism of action.


Assuntos
Bismuto , Povidona , Simulação de Acoplamento Molecular , Povidona/farmacologia , Bismuto/química , Luz , Corantes/farmacologia , Escherichia coli , Antibacterianos/farmacologia , Antibacterianos/química
5.
ACS Omega ; 8(38): 34805-34815, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37779977

RESUMO

This study was used to evaluate the catalytic activity (CA) and bactericidal activity of α-MoO3 and Sm-g-C3N4-doped α-MoO3 composites prepared through an efficient, cost-effective coprecipitation route. Their characteristic studies verify the formation of α-MoO3 and its composites (3, 6, and 9 mL Sm-g-C3N4-doped α-MoO3), which showed high crystallinity, as confirmed by X-ray diffraction (XRD) analysis. The production of superoxide and hydroxyl radicals due to charge transfer through α-MoO3 and g-C3N4 eventually forms electrons in g-C3N4 and holes around α-MoO3. CA against Rhodamine B (RhB) in basic medium provides maximum results compared to acidic and neutral media. The bactericidal efficacy of the (9 mL) doped sample represents a greater inhibition zone of 6.10 mm against the negative bacterial strain Escherichia coli. Furthermore, in silico studies showed that the generated nanorods may inhibit DNA gyrase and dihydropteroate synthase (DHPS) enzymes.

6.
ACS Omega ; 8(40): 37564-37572, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37841132

RESUMO

As the population grows, the scientific community remains focused on researching new materials, methods, and devices to ensure the availability of safe drinking water. The main aim of this research was to decrease the recombination rate of the charge carriers of La2O3 and enhance the catalytic and antimicrobial activity by employing Y/Cs- doped La2O3, respectively. In the current study, different concentrations of yttrium (Y) and a fixed amount of carbon spheres (Cs) doped into lanthanum oxide (La2O3) nanostructures (NSs) were synthesized by the coprecipitation technique. Cs are used as a cocatalyst as they have a high surface area and small size attributed to increased active sites and decreased recombination rate. Moreover, Y was further incorporated as it activates the generation of reactive oxygen species in the inhibition zone, enhancing the antibacterial activity and reducing the emission intensity. Advanced techniques were utilized to determine the structural properties, optical emission and absorption, elemental composition, and d-spacing of the synthesized samples. The reported ternary catalyst works efficiently, improving the catalytic activity and bactericidal potential. Moreover, in silico molecular docking studies, Cs-doped La2O3 and Y/Cs-doped La2O3 nanostructures toward DNA gyrase Escherichia coli showed good efficacy for antibacterial activity.

7.
RSC Adv ; 13(37): 26149-26159, 2023 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-37664196

RESUMO

This research presents the novel synthesis of CeO2 nanostructures (NSs) doped with a fixed amount of capping agent (polyacrylic acid-PAA) and different concentrations (0.01 and 0.03) of silver (Ag). This work aimed to examine the catalytic and antibacterial efficacy with evidential molecular docking analysis of Ag/PAA doped CeO2. Systematic characterization was used to analyze the effect of Ag and a capping agent on crystal structure, morphology, absorbance wavelength, and the exciton recombination rate of CeO2. The silver metal and capping agent (PAA) were added into CeO2 to reduce the size of NSs, enhancing the catalytic efficacy. These binary dopants (Ag-PAA) based CeO2 revealed remarkable results for catalytic de-colorization of rhodamine B dye and antimicrobial potential as the dopants provide more active sites. Notably, (0.03) Ag/PAA doped CeO2 NSs exhibited a substantial catalytic reduction (98.9%) of rhodamine B dye in an acidic medium. The higher doped CeO2 revealed a significant inhibition zone (3.75 mm) against Escherichia coli at maximal concentration. Furthermore, in silico docking showed the possible inhibitory impact of produced nanomaterials on the fatty acid biosynthesis enzymes FabI and FabH.

8.
RSC Adv ; 13(40): 28008-28020, 2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37746345

RESUMO

In this research, a fixed concentration (3 wt%) of Ag/PAA and PAA/Ag doped graphene quantum dots (GQDs) were synthesized using the co-precipitation technique. A variety of characterization techniques were employed to synthesize samples to investigate their optical, morphological, structural, and compositional analyses, antimicrobial efficacy, and dye degradation potential with molecular docking analysis. GQDs have high solubility, narrow band gaps, and are suitable for electron acceptors and donors but show less adsorption and catalytic behavior. Incorporating polyacrylic acid (PAA) into GQDs increases the catalytic and antibacterial activities due to the carboxylic group (-COOH). Furthermore, introducing silver (Ag) increased the degradation of dye and microbes as it had a high surface-to-volume ratio. In addition, molecular docking studies were used to decipher the mechanism underlying the bactericidal action of silver and polyacrylic acid-doped graphene quantum dots and revealed inhibition of ß-lactamase and DNA gyrase.

9.
Int J Biol Macromol ; 253(Pt 2): 126501, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37678687

RESUMO

Aspirin is a prevalent over-the-counter medicine that has been categorized as an emerging contaminant due to its danger to both living things and the environment. This work presents chitosan modified with spent tea waste extract (STWE) via the wet impregnation method as an adsorbent for the enhanced removal of aspirin in a fixed-bed column. The adsorbent (named chitosan-STWE) was successfully synthesized and exhibited a low crystallinity structure, good stability against thermal and acidic conditions, as depicted by HNMR, XRD, TGA, and the dissolution rate of the adsorbent. The adsorption column study reveals that increasing bed height (up to 6 cm) increases the percentage of aspirin removal (up to 40.8 %). Increasing aspirin concentration enhances the amount of aspirin that comes into contact with the chitosan-STWE adsorbent, thereby increasing the adsorption capacity. On the other hand, higher flow rates result in shorter contact times between the adsorbent and adsorbates, which lowers the quantity of aspirin adsorbed. The experimental data are in accordance with the values generated by the Thomas and Yoon-Nelson models, with the maximum adsorption capacity of 61.7 mg/g. The chitosan-STWE adsorbent was determined to be non-toxic, thus safe to be used in wastewater treatment applications.


Assuntos
Quitosana , Poluentes Químicos da Água , Purificação da Água , Adsorção , Quitosana/química , Aspirina , Poluentes Químicos da Água/química , Purificação da Água/métodos , Chá
10.
Environ Toxicol Pharmacol ; 102: 104248, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37598982

RESUMO

Nowadays, microplastic pollution is one of the globally urgent concerns as a result of discharging plastic products into the atmosphere, aquatic and soil environments. Microplastics have average size of less than 5 mm, are non-biodegradable, accumulative, and highly persistent substances. Thousands of tons of microplastics are still accumulated in various environments, posing an enormous threat to human health and living creatures. Here, we review the occurrence and analytical methods, and impact of microplastics in the environments including soil, aquatic media, and atmosphere. Analytical methods including visual observation, Fourier-transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and pyrolysis-gas chromatography-mass spectrometry were evaluated. We elucidated the environmental and human health impacts of microplastics with emphasis on life malfunction, immune disruption, neurotoxicity, diseases and other tangible health risks. This review also found some shortages of analytical equivalence and/or standardization, inconsistence in sampling collection and limited knowledge of microplastic toxicity. It is hopeful that the present work not only affords a more insight into the potential dangers of microplastics on human health but also urges future researches to establish new standardizations in analytical methods.


Assuntos
Microplásticos , Plásticos , Humanos , Microplásticos/toxicidade , Plásticos/toxicidade , Poluição Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Solo
11.
Chemosphere ; 340: 139855, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37611764

RESUMO

Contaminants removal is usually becoming an exciting subject of research from water considering their environmental and ecological effects. This work provides pathways to remove organic pollutants from water via nanomaterials and is used as an antibiotic against bacteria like Escherichia coli (E. coli). In this study, molybdenum trioxide (MoO3) and yttrium (Y) doped (2 and 4%) MoO3 nanorods were synthesized by co-precipitation method. Advanced characterization techniques have been introduced to study textural structures, morphological developments, and optical characteristics of produced products. X-ray diffraction studied multiple crystalline structures of prepared samples as hexagonal, orthorhombic, and monoclinic of pure MoO3 with decrease in crystallinity and crystallite size upon Y doping. UV-visible spectroscopy unveiled a redshift (bathochromic effect) in absorption pattern attributed to band gap energy (Eg) decreases. Photoluminescence spectra examined the recombination rate of electrons (e-) and holes (h+) as charge carriers. A sufficient catalytic activity (CA) was observed against methylene blue (MB) dye in an acidic medium (99.74%) and efficient bactericidal action was studied against (E. coli) with zone of inhibition (5.20 mm) for 4% Y-doped MoO3. In addition, in silico docking demonstrated potential inhibitory effect of produced nanomaterials on FabH and FabI enzymes of fatty acid biosynthesis.


Assuntos
Escherichia coli , Nanotubos , Simulação de Acoplamento Molecular , Antibacterianos/farmacologia
12.
ACS Omega ; 8(33): 30681-30693, 2023 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-37636921

RESUMO

Cationic dyes present in industrial effluents significantly reduce the effectiveness of remediation operations. Considering the terrible impact of these pollutants on environment and biodiversity, investigating strategies to remove potentially harmful compounds from water is becoming an increasingly intriguing issue. In this work, we employed a simple hydrothermal technique to synthesize Fe-doped CdO (2, 4, and 6 wt %) nanostructures and assessed their efficacy in degrading methylene blue (MB) dye and inhibiting the growth of Staphylococcus aureus and Escherichia coli, respectively. Structural, morphological, and optical characterization of produced nanomaterials was also performed using X-ray diffraction, TEM, and UV absorption spectra. The photocatalytic decomposition of MB was significantly enhanced (58.8%) by using Fe (6 wt %)-doped CdO catalysts for 80 min under irradiation. In addition, 2.05-5.05 mm inhibitory zones were seen against Gram-positive bacteria (S. aureus), whereas the range for Gram-negative bacteria (E. coli) was 1.65-2.75 mm. These nanostructures were shown to be very effective inhibitors of beta-lactamase, d-alanine-d-alanine ligase B, and fatty acid synthase inhibitor by in silico molecular docking investigations.

13.
Glob Chall ; 7(8): 2300047, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37635702

RESUMO

Microplastic pollution has adversely affected the aquatic ecosystem, living creatures, and human health. Several studies in Malaysia have provided baseline information on the existence of microplastics in surface water, ingestion by marine life and sediment. Also, humans are exposed to microplastic due to consumption of contaminated abiotic and biotic products, such as processed seafood. Nonetheless, knowledge is still scarce among Malaysian on the potential remediation and pollution management of microplastics, which poses a significant challenge to preserve a good environmental status. Green technologies also other alternative to mitigate the contamination of microplastics for sustainable future. Hence, this review aims to provide an overview of microplastic's occurrence, fate, and implications in Malaysia's aquatic environment. Detection of microplastics from the water surface, ingestion by aquatics, and sediment samples are highlighted. Available different treatment processes toward microplastic remediation are also discussed. Additionally, the potential challenges, current perspective for plastic management in Malaysia, as well as green strategies for reducing microplastic contamination are also put forward. The goal of this work is to improve the understanding of the seriousness of microplastic contamination in aquatic environments, thus encouraging key concerns that need to be investigated further.

14.
RSC Adv ; 13(36): 25305-25315, 2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37622014

RESUMO

Herein, Bi2O3 quantum dots (QDs) have been synthesized and doped with various concentrations of graphitic carbon nitride (g-C3N4) and a fixed amount of carbon spheres (CS) using a co-precipitation technique. XRD analysis confirmed the presence of monoclinic structure along the space group P21/c and C2/c. Various functional groups and characteristic peaks of (Bi-O) were identified using FTIR spectra. QDs morphology of Bi2O3 showed agglomeration with higher amounts of g-C3N4 by TEM analysis. HR-TEM determined the variation in the d-spacing which increased with increasing dopants. These doping agents were employed to reduce the exciting recombination rate of Bi2O3 QDs by providing more active sites which enhance antibacterial activity. Notably, (6 wt%) g-C3N4/CS-doped Bi2O3 exhibited considerable antimicrobial potential in opposition to E. coli at higher values of concentrations relative to ciprofloxacin. The (3 wt%) g-C3N4/CS-doped Bi2O3 exhibits the highest catalytic potential (97.67%) against RhB in a neutral medium. The compound g-C3N4/CS-Bi2O3 has been suggested as a potential inhibitor of ß-lactamaseE. coli and DNA gyraseE. coli based on the findings of a molecular docking study that was in better agreement with in vitro bactericidal activity.

15.
Pharmaceuticals (Basel) ; 16(7)2023 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-37513835

RESUMO

Breast cancer is considered the second-leading cancer after lung cancer and is the most prevalent cancer among women globally. Currently, cancer immunotherapy via vaccine has gained great attention due to specific and targeted immune cell activity that creates a potent immune response, thus providing long-lasting protection against the disease. Despite peptides being very susceptible to enzymatic degradation and poor immunogenicity, they can be easily customized with selected epitopes to induce a specific immune response and particulate with carriers to improve their delivery and thus overcome their weaknesses. With advances in nanotechnology, the peptide-based vaccine could incorporate other components, thereby modulating the immune system response against breast cancer. Considering that peptide-based vaccines seem to show remarkably promising outcomes against cancer, this review focuses on and provides a specific view of peptide-based vaccines used against breast cancer. Here, we discuss the benefits associated with a peptide-based vaccine, which can be a mainstay in the prevention and recurrence of breast cancer. Additionally, we also report the results of recent trials as well as plausible prospects for nanotechnology against breast cancer.

16.
ACS Omega ; 8(28): 25401-25409, 2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37483192

RESUMO

This work demonstrates the degradation of toxic RhB (rhodamine B) dye from polluted water in various pH environments. It assesses the antibacterial action of CDs (carbon dots)/CS (chitosan)-doped La2O3 (lanthanum oxide) NRs (nanorods). CS and CDs have been introduced as dopants to modify the characteristics of La2O3 to achieve efficient outcomes. The influence of doping on the structural, morphological, optical, and elemental properties of synthesized La2O3 NRs was investigated through a number of analytical techniques. The structural analysis of XRD revealed a hexagonal phase. The rod-like structure of pure La2O3 and reduction in the size of NRs upon doping were exhibited by TEM micrographs. From UV-vis spectroscopy, increased absorption upon doping and introduction of redshift that led to reduced bandgap energy were observed. The FTIR spectra indicate the presence of functional groups of pure and integrated samples. The catalytic activity of specimens in basic medium toward dye showed excellent results (94.57%). The inhibition zone of diameter 4.15 mm was evaluated by 6 mL of CDs/CS-doped La2O3 NRs against Escherichia coli once the surface area increased by dopants. In silico experiments were performed for enoyl-[acyl-carrier-protein] reductase (FabI) and DNA gyrase enzymes to assess the potency of CS-doped La2O3 and CDs/CS-doped La2O3 as their inhibitors and to justify their possible mechanism of action.

18.
Glob Chall ; 7(6): 2300001, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37287595

RESUMO

A wide range of hard contaminants in wastewater is generated from different industries as byproducts of the organic compound. In this review, various metal oxide-based nanomaterials are employed for the photocatalytic removal of malachite green (MG) dye from wastewater. Some cost-effective and appropriate testing conditions are used for degrading these hard dyes to get higher removal efficiency. The effects of specific parameters are considered such as how the catalyst is made, how much dye is in the solution at first, how much nanocatalyst is needed to break down the dye, the initial pH of the dye solution, the type of light source used, the year of publications, and how long the dye has to be exposed to light to be removed. This study suggests that Scopus-based core collected data employ bibliometric methods to provide an objective analysis of global MG dye from 2011 to 2022 (12 years). The Scopus database collects all the information (articles, authors, keywords, and publications). For bibliometric analysis, 658 publications are retrieved corresponding to MG dye photodegradation, and the number of publications increases annually. A bibliometric study reveals a state-of-art review of metal oxide-based nanomaterials' effects on photocatalytic degradation of MG dyes (12 years).

19.
ACS Omega ; 8(22): 19474-19485, 2023 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-37305260

RESUMO

Vanadium oxide (V2O5) and carbon spheres (Cs)-doped NiO2 nanostructures (NSs) were prepared using the co-precipitation approach. Several spectroscopic and microscopic techniques, including X-ray diffraction (XRD), UV-vis, FTIR, TEM, and HR-TEM investigations, were used to describe the as-synthesized NSs. The XRD pattern exhibited the hexagonal structure, and the crystallite size of pristine and doped NSs was calculated as 29.3, 32.8, 25.79, and 45.19 nm, respectively. The control sample (NiO2) showed maximum absorption at 330 nm, and upon doping, a redshift was observed, leading to decreased band gap energy from 3.75 to 3.59 eV. TEM of NiO2 shows agglomerated nonuniform nanorods exhibited with various nanoparticles without a specific orientation; a higher agglomeration was observed upon doping. The (4 wt %) V2O5/Cs-doped NiO2 NSs served as superior catalysts with a 94.21% MB reduction in acidic media. The significant antibacterial efficacy was estimated against Escherichia coli by measuring the zone of inhibition (3.75 mm). Besides their bactericidal analysis, V2O5/Cs-doped NiO2 was shown to have a binding score of 6.37 for dihydrofolate reductase and a binding score of 4.31 for dihydropteroate synthase in an in silico docking study of E. coli.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...