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1.
Chem Commun (Camb) ; 57(83): 10903-10906, 2021 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-34590104

RESUMO

We report here a novel photocurrent polarity switching strategy for a photoelectrochemical immunoassay driven by the covalent reaction between fullerenol (COH) and chloranilic acid (CA). The sensitive detection of interleukin-6 is achieved by using CA-encapsulated liposome as the label and COH-coated ZnO as the photoactive material, with a detection limit of 1.0 fg mL-1.


Assuntos
Fulerenos/química , Interleucina-6/sangue , Nanotubos/química , Óxido de Zinco/química , Anticorpos/imunologia , Benzoquinonas/química , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Fulerenos/efeitos da radiação , Humanos , Imunoensaio/métodos , Interleucina-6/imunologia , Limite de Detecção , Lipossomos/química , Nanotubos/efeitos da radiação , Processos Fotoquímicos , Compostos de Estanho/química , Óxido de Zinco/efeitos da radiação
2.
Carbohydr Polym ; 268: 118235, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34127218

RESUMO

In-depth understanding of interfacial property is the key to guiding the synthesis of biomass composites with desired performance. However, the exploration is of great challenge due to limitations of experimental techniques in locating hydrogen, requiring large/good crystals and detecting a weak interaction like van der Waals (vdW). Herein, we experimentally and computationally investigated the composite cellulose/zinc oxide/g-C3N4. Hydrothermal synthesis afforded cellulose/ZnO, and then fabricated the ternary composite by adding g-C3N4 under ultrasonic condition. Three components are found to co-exist in the composite, and the ZnO nanoparticle is attaching to cellulose and coupling with g-C3N4. These experimental findings were corroborated by relativistic DFT calculations. The interfacial coupling is elaborated as contributions of dative bonds, hydrogen bonds and vdW interaction. The vdW is increased by a factor of 4.23 in the ZnO/g-C3N4 interface. This improves electron-hole separation and offers prospective application of the composite in photocatalysis, antibacteria and gas sensing.


Assuntos
Celulose/química , Grafite/química , Nanocompostos/química , Compostos de Nitrogênio/química , Óxido de Zinco/química , Catálise/efeitos da radiação , Celulose/efeitos da radiação , Teoria da Densidade Funcional , Grafite/efeitos da radiação , Luz , Modelos Químicos , Nanocompostos/efeitos da radiação , Compostos de Nitrogênio/efeitos da radiação , Eletricidade Estática , Óxido de Zinco/efeitos da radiação
3.
ACS Appl Mater Interfaces ; 13(9): 10719-10727, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33645209

RESUMO

This work reports the study of ZnO-based anodes for the photoelectrochemical regeneration of the oxidized form of nicotinamide adenine dinucleotide (NAD+). The latter is the most important coenzyme for dehydrogenases. However, the high costs of NAD+ limit the use of such enzymes at the industrial level. The influence of the ZnO morphologies (flower-like, porous film, and nanowires), showing different surface area and crystallinity, was studied. The detection of diluted solutions (0.1 mM) of the reduced form of the coenzyme (NADH) was accomplished by the flower-like and the porous films, whereas concentrations greater than 20 mM were needed for the detection of NADH with nanowire-shaped ZnO-based electrodes. The photocatalytic activity of ZnO was reduced at increasing concentrations of NAD+ because part of the ultraviolet irradiation was absorbed by the coenzyme, reducing the photons available for the ZnO material. The higher electrochemical surface area of the flower-like film makes it suitable for the regeneration reaction. The illumination of the electrodes led to a significant increase on the NAD+ regeneration with respect to both the electrochemical oxidation in dark and the only photochemical reaction. The tests with formate dehydrogenase demonstrated that 94% of the regenerated NAD+ was enzymatically active.


Assuntos
Técnicas Eletroquímicas/instrumentação , Eletrodos , NAD/química , Fotoquímica/instrumentação , Óxido de Zinco/química , Formiato Desidrogenases/química , Proteínas Fúngicas/química , Nanofios/química , Nanofios/efeitos da radiação , Oxirredução , Saccharomycetales/enzimologia , Raios Ultravioleta , Óxido de Zinco/efeitos da radiação
4.
ACS Appl Mater Interfaces ; 13(9): 10878-10890, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33635062

RESUMO

In order to solve two issues of chlorine-resistant bacteria (CRB) and disinfection byproducts (DBPs) in tap water after the chlorine-containing treatment process, an innovative core-sheath nanostructured Cu/Cu2O-ZnO-Fe3O4 was designed and synthesized. The fabrication mechanism of the materials was then systematically analyzed to determine the component and valence state. The properties of CRB inactivation together with trichloroacetic acid (TCAA) photodegradation by Cu/Cu2O-ZnO-Fe3O4 were investigated in detail. It was found that Cu/Cu2O-ZnO-Fe3O4 displayed excellent antibacterial activity with a relatively low cytotoxicity concentration due to its synergism of nanowire structure, ion release, and reactive oxygen species generation. Furthermore, the Cu/Cu2O-ZnO-Fe3O4 nanocomposite also exhibited outstanding photocatalytic degradation activity on TCAA under simulated sunlight irradiation, which was verified to be dominated by the surface reaction through kinetic analysis. More interestingly, the cell growth rate of Cu/Cu2O-ZnO-Fe3O4 was determined to be 50% and 10% higher than those of Cu/Cu2O and Cu/Cu2O-ZnO after 10 h incubation, respectively, manifesting a weaker cytotoxicity. Therefore, the designed Cu/Cu2O-ZnO-Fe3O4 could be a promising agent for tap water treatment.


Assuntos
Antibacterianos/farmacologia , Cobre/farmacologia , Nanopartículas de Magnetita/química , Nanocompostos/química , Ácido Tricloroacético/química , Óxido de Zinco/farmacologia , Antibacterianos/química , Antibacterianos/efeitos da radiação , Antibacterianos/toxicidade , Bactérias/efeitos dos fármacos , Catálise/efeitos da radiação , Cobre/química , Cobre/efeitos da radiação , Células HeLa , Humanos , Nanopartículas de Magnetita/efeitos da radiação , Nanopartículas de Magnetita/toxicidade , Testes de Sensibilidade Microbiana , Nanocompostos/efeitos da radiação , Nanocompostos/toxicidade , Oxirredução , Fotólise/efeitos da radiação , Esterilização/métodos , Luz Solar , Purificação da Água/métodos , Óxido de Zinco/química , Óxido de Zinco/efeitos da radiação , Óxido de Zinco/toxicidade
5.
Bioorg Chem ; 103: 104194, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32890997

RESUMO

In this study, CoFe2O4@ZnO-CeO2 magnetic nanocomposite (CoFe@Zn-Ce MNC) was successfully prepared by facile sonochemical method for the first time. CoFe@Zn-Ce MNC was obtained by green and cost-effective process in the presence of Crataegus microphylla (C. microphylla) fruit extract. Influence of some parameters like capping agents (C. microphylla, SDS and CTAB), sonication time (10, 30 and 60 min) and sonication power (40, 60 and 80 W) were studied to achieve optimum condition. The as-obtained products were characterized by FT-IR, FESEM, TEM, DRS, VSM, EDS, TGA and XRD analysis. Results showed that high magnetic properties (20.38 emug-1), 70-80 nm size and spherical morphology were unique characteristics of synthesized nanocomposite. Antibacterial activity of CoFe@Zn-Ce MNC was examined against E. coli, P. aeruginoss and S. aureus bacteria. Among theme, S. aureus as gram-positive bacteria showed excellent antibacterial activity. Furthermore, photocatalytic performance of the CoFe@Zn-Ce MNC was investigated by degradation of humic acid (HA) molecules under visible and UV light irradiations. The influence of morphology of products and incorporation of cerium oxide with CoFe2O4@ZnO on photocatalytic activity of CoFe2O4@ZnO was performed. After 100 min illumination, the decomposition of HA pollutant by magnetic nanocomposite were 97.2% and 72.4% under exposure of UV and visible light irradiations, respectively. Also, CoFe@Zn-Ce MNC demonstrated high stability in the cycling decomposition experiment after six times cycling runs.


Assuntos
Antibacterianos/farmacologia , Crataegus/química , Nanocompostos/química , Extratos Vegetais/química , Antibacterianos/síntese química , Antibacterianos/efeitos da radiação , Catálise/efeitos da radiação , Cério/química , Cério/efeitos da radiação , Cobalto/química , Cobalto/efeitos da radiação , Compostos Férricos/química , Compostos Férricos/efeitos da radiação , Química Verde/métodos , Substâncias Húmicas , Fenômenos Magnéticos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/efeitos da radiação , Testes de Sensibilidade Microbiana , Nanocompostos/efeitos da radiação , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Ondas Ultrassônicas , Raios Ultravioleta , Óxido de Zinco/química , Óxido de Zinco/efeitos da radiação
6.
Int J Biol Macromol ; 165(Pt A): 71-81, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32987081

RESUMO

We aimed to provide a tissue repair material, which can be synthesized rapidly, using polymers mimicking the natural environment in the extra-cellular matrix and metals/minerals. The components should have the potential to be used in tissue repair and simultaneously, reducing the side-effects of the incorporated molecules. It is challenging to manage the dispersibility of ZnO NPs in common solutions like water. Here, we report a novel method for preparing highly dispersible suspensions of ZnO NPs. In contrast to those synthesized by conventional methods, microwave assisted method allowed synthesis of dispersible ZnO NPs and the incorporation of zinc/Iron oxides NPs within alginate and gum matrix (AG) in a short span of time providing high yield of the product. The nanoformulations were characterized for size, morphology, interaction of various chemicals used during their synthesis by transmissible electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and energy dispersive X ray Spectrum. It was also evaluated for cytotoxicity and their effect on equine fibroblast cells. Microwave-assisted fabrication of zinc/iron oxides nanoparticles provided flowerlike morphology with good dispersibility and high yield in a short span of time. Our results revealed that ZnO NPs were more cytotoxic than AG ZnO NPs and doped AG Fe3O4 doped ZnO NPs at higher concentrations. Further metal nanoparticles capped with alginate/acacia with size range less than 100 nm demonstrated high stability, good biocompatibility, re-epithelization and enhanced mineralization in horse fibroblast cells.


Assuntos
Compostos Férricos/química , Nanopartículas Metálicas/química , Nanocompostos/química , Óxido de Zinco/química , Animais , Compostos Férricos/farmacologia , Compostos Férricos/efeitos da radiação , Fibroblastos/efeitos dos fármacos , Cavalos , Nanopartículas Metálicas/efeitos da radiação , Microscopia Eletrônica de Varredura , Micro-Ondas , Nanocompostos/efeitos da radiação , Espectroscopia de Infravermelho com Transformada de Fourier , Óxido de Zinco/farmacologia , Óxido de Zinco/efeitos da radiação
7.
J Mater Chem B ; 8(36): 8444-8458, 2020 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-32812631

RESUMO

A facile, green synthesis of selenium doped zinc oxide nano-antibiotic (Se-ZnO-NAB) using the Curcuma longa extract is reported to combat the increased emergence of methicillin-resistant Staphylococcus aureus (MRSA). The developed Se-ZnO-NAB were characterized for their physicochemical parameters and extensively evaluated for their toxicological potential in an animal model. The prepared Se-ZnO-NABs were characterized via Fourier transformed infrared spectroscopy to get functional insight into their surface chemistry, scanning electron microscopy revealing the polyhedral morphology with a size range of 36 ± 16 nm, having -28.9 ± 6.42 mV zeta potential, and inductively coupled plasma optical emission spectrometry confirming the amount of Se and Zn to be 14.43 and 71.70 mg L-1 respectively. Moreover, the antibacterial activity against MRSA showed significantly low minimum inhibitory concentration at 6.2 µg mL-1 when compared against antibiotics. Also, total protein content and reactive oxygen species production in MRSA, under the stressed environment of Se-ZnO-NAB, significantly (p < 0.05) decreased compared to the negative control. Moreover, the results of acute oral toxicity in rats showed moderate variations in blood biochemistry and histopathology of vital organs. The teratogenicity and fetal evaluations also revealed some signs of toxicity along with changes in biochemical parameters. The overall outcomes suggest that Se-ZnO-NAB can be of significant importance for combating multi-drug resistance but must be used with extreme caution, particularly in pregnancy, as moderate toxicity was observed at a toxic dose of 2000 mg kg-1.


Assuntos
Antibacterianos/farmacologia , Nanopartículas Metálicas/química , Extratos Vegetais/farmacologia , Animais , Antibacterianos/síntese química , Antibacterianos/efeitos da radiação , Antibacterianos/toxicidade , Curcuma/química , Feminino , Química Verde , Luz , Nanopartículas Metálicas/efeitos da radiação , Nanopartículas Metálicas/toxicidade , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Extratos Vegetais/toxicidade , Gravidez , Ratos Wistar , Selênio/química , Selênio/efeitos da radiação , Selênio/toxicidade , Teratogênicos/síntese química , Teratogênicos/farmacologia , Teratogênicos/efeitos da radiação , Teratogênicos/toxicidade , Óxido de Zinco/química , Óxido de Zinco/efeitos da radiação , Óxido de Zinco/toxicidade
8.
J Mater Chem B ; 8(36): 8294-8304, 2020 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-32785373

RESUMO

Highly efficient photoactive antimicrobial coatings were obtained using zinc oxide-reduced graphene oxide nanocomposites (ZnO-rGO). Their remarkable antibacterial activity and high stability demonstrated their potential use for photoactive biocide surfaces. The ZnO-rGO nanocomposites were prepared by the sol-gel technique to create photocatalytic surfaces by spin-coating. The coatings were deeply characterised and several tests were performed to assess the antibacterial mechanisms. rGO was homogeneously distributed as thin sheets decorated with ZnO nanoparticles. The surface roughness and the hydrophobicity increased with the incorporation of graphene. The ZnO-rGO coatings exhibited high activity against the Gram-positive bacterium Staphylococcus aureus. The 1 wt% rGO coated surfaces showed the highest antibacterial effect in only a few minutes of illumination with up to 5-log reduction in colony forming units, which remained essentially free of bacterial colonization and biofilm formation. We demonstrated that these coatings impaired the bacterial cells due to cell membrane damage and intracellular oxidative stress produced by the photogenerated reactive-oxygen species (ROS). The enhancement of the ZnO photocatalytic performance upon rGO incorporation is due to the increased detected generation of hydroxyl radicals, attributed to the reduction of electron-hole pair recombination. This intimate contact between both components also conveyed stability against zinc leaching and improved the coating adhesion.


Assuntos
Antibacterianos/farmacologia , Grafite/farmacologia , Nanocompostos/química , Óxido de Zinco/farmacologia , Antibacterianos/química , Antibacterianos/efeitos da radiação , Grafite/química , Grafite/efeitos da radiação , Luz , Teste de Materiais , Testes de Sensibilidade Microbiana , Nanocompostos/efeitos da radiação , Staphylococcus aureus/efeitos dos fármacos , Óxido de Zinco/química , Óxido de Zinco/efeitos da radiação
9.
J Hazard Mater ; 393: 122490, 2020 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-32197201

RESUMO

In this work, we have investigated the stability of pindolol (PIN), a non-selective ß1-blocker detected in the river and wastewater of hospitals, in water solution under solar irradiation. Further, detailed insights into the stability of PIN were obtained by the density functional theory (DFT) calculations and molecular dynamics simulations. The kinetics of PIN photocatalytic degradation and mineralization has been studied using four commercial photocatalysts ZnO and TiO2 (P25, Hombikat, and Wackherr). It was found that the major role in degradation of PIN play the reactive hydroxyl radicals. The structures of degradation intermediates were suggested by LC-ESI-MS/MS and DFT calculations. Also, DFT calculations were used to refine molecular structures of intermediates and obtain their geometries. Toxicity of PIN and its mixtures formed during photocatalytic degradation were investigated using mammalian cell lines (H-4-II-E, HT-29, and MRC-5). The H-4-II-E cell line was the most sensitive to PIN and its photodegradation mixtures. The computational results were combined with the experimental data on the amounts of degradation intermediates for determination of the intermediates that were principally responsible for the toxicity. Intermediate with two hydroxyl groups, positioned on indole ring in meta and para positions, was proposed as the one with the highest contribution to toxicity.


Assuntos
Pindolol/química , Luz Solar , Titânio/efeitos da radiação , Poluentes Químicos da Água/química , Óxido de Zinco/efeitos da radiação , Animais , Catálise , Linhagem Celular , Humanos , Cinética , Modelos Moleculares , Fotólise , Pindolol/toxicidade , Ratos , Titânio/química , Poluentes Químicos da Água/toxicidade , Óxido de Zinco/química
10.
J Hazard Mater ; 393: 122491, 2020 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-32197202

RESUMO

The adsorption with highly porous adsorbents is an efficient technique to trap the uncontrolled release of antibiotics in the environment, however, mere adsorption does not mineralize the discharged antibiotics. On the contrary, the regular photocatalysts completely mineralize the antibiotics, however suffers from high efficiency due to comparatively low surface area and porosity. In this work, a balance has been made between efficient adsorption followed by complete degradation of the adsorbed antibiotic over ZIF-8 derived ZnO/N-doped carbon composite. The nitrogen-doped carbon produced at 1000 °C showed a very high adsorption capacity of SMX, due to higher surface area, porosity and better surface interaction between adsorbate and adsorbent. The ZnO formed at 600 °C produced sufficient OH· that were responsible to show a very high rate of complete photocatalytic mineralization of SMX over the material. The ZnO/N-doped carbon composite showed a very high rate of photodegradation with a corresponding rate constant of 4.36 × 10-2 min-1. The complete degradation mechanism was proposed and rates were compared with existing literature.


Assuntos
Antibacterianos/química , Carbono/efeitos da radiação , Nanocompostos/efeitos da radiação , Nitrogênio/efeitos da radiação , Sulfametoxazol/química , Poluentes Químicos da Água/química , Óxido de Zinco/efeitos da radiação , Adsorção , Carbono/química , Catálise , Imidazóis/química , Estruturas Metalorgânicas/química , Nanocompostos/química , Nitrogênio/química , Fotólise , Zeolitas/química , Óxido de Zinco/química
11.
J Hazard Mater ; 392: 122331, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32097858

RESUMO

The emergence of more and more persistent organic molecules as contaminants in water simulates research towards the development of more advanced technologies, among which photocatalysis is a feasible choice. However, it is still challenging to design a photocatalyst that fulfills all the requirements for industrial application, i.e., active under visible-light irradiation, shape with handy convenience, highly uniform distribution of active sites, substrate with excellent electronic properties, etc. In this study, we report an attempt to solve these issues at once by designing a film-like photocatalyst with uniform distribution of nitrogen-doped ZnO nanoparticles along nitrogen-doped carbon ultrafine nanofibers with three-dimensional interconnected structure. Under visible-light irradiation, the product exhibited remarkable reactivity for the degradation of two model pollutants tetracycline hydrochloride and 2,4-dichlorophenol within 100 min. The cyclic experiments demonstrated only a slight loss (ca. 5 %) of reactivity after five consecutive photocatalytic reactions. We also investigated the detailed relationship between the structural features and the superior properties of this product, as well as the degradation mechanisms. The convenient shape of the product with excellent performances for the treatment of real polluted water increases its suitability for larger scale application. Our work provides a rational design of photocatalysts for environmental remediation.


Assuntos
Carbono/efeitos da radiação , Clorofenóis/química , Luz , Nanofibras/efeitos da radiação , Nitrogênio/efeitos da radiação , Tetraciclina/química , Poluentes Químicos da Água/química , Óxido de Zinco/efeitos da radiação , Carbono/química , Catálise , Óxidos N-Cíclicos/química , Nanofibras/química , Nitrogênio/química , Fotólise , Purificação da Água/métodos , Zeolitas/química , Óxido de Zinco/química
12.
J Hazard Mater ; 381: 120958, 2020 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-31416043

RESUMO

While bulk zinc oxide (ZnO) is of non-toxic in nature, ZnO nanoarchitectures could potentially induce the macroscopic characteristics of oxidative, lethality and toxicity in the water environment. Here we report a systematic study through state-of-the-art controllable synthesis of multi-dimensional ZnO nanoarchitectures (i.e. 0D-nanoparticle, 1D-nanorod, 2D-nanosheet, and 3D-nanoflowers), and subsequent in-depth understanding on the fundamental factor that determines their photoactivities. The photoactivities of resultant ZnO nanoarchitectures were interpreted in terms of the photodegradation of salicylic acid as well as inactivation of Bacillus subtilis and Escherichia coli under UV-A irradiation. Photodegradation results showed that 1D-ZnO nanorods demonstrated the highest salicylic acid photodegradation efficiency (99.4%) with a rate constant of 0.0364 min-1. 1D-ZnO nanorods also exhibited the highest log reductions of B. subtilis and E. coli of 3.5 and 4.2, respectively. Through physicochemical properties standardisation, an intermittent higher k value for pore diameter (0.00097 min-1 per mm), the highest k values for crystallite size (0.00171 min-1 per nm) and specific surface area (0.00339 min-1 per m2/g) contributed to the exceptional photodegradation performance of nanorods. Whereas, the average normalised log reduction against the physicochemical properties of nanorods (i.e. low crystallite size, high specific surface area and pore diameter) caused the strongest bactericidal effect.


Assuntos
Nanoestruturas/química , Nanoestruturas/efeitos da radiação , Raios Ultravioleta , Óxido de Zinco/química , Óxido de Zinco/efeitos da radiação , Bacillus subtilis/crescimento & desenvolvimento , Catálise , Escherichia coli/crescimento & desenvolvimento , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Nanoestruturas/ultraestrutura , Fotólise , Espécies Reativas de Oxigênio/química , Ácido Salicílico/química
13.
Environ Int ; 132: 105105, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31437644

RESUMO

Increasing concentrations of anthropogenic antibiotics and their metabolites in aqueous environments has caused growing concerns over the proliferation of antibiotic resistance and potential adverse impacts to agro-environmental quality and human health. Photocatalysis using novel engineered nanomaterials such as ZnO nanowires may be promising for removing antibiotics from waters. However, much remains to be learned about efficiency and mechanism for photocatalytic degradation of antibiotics by ZnO nanowires. This study systematically investigated photodegradation of cephalexin using ZnO nanowires under simulated sunlight. The degradation efficiency of cephalexin was substantially increased in the presence of ZnO nanowires especially at circumneutral and alkaline condition (solution pH of 7.2-9.2). The photodegradation followed the first-order kinetics with degradation rate constants (k) ranging between 1.19 × 10-1 and 2.52 × 10-1 min-1 at 20-80 mg L-1 ZnO nanowires. Radical trapping experiments demonstrated that hydroxyl radicals (OH) and superoxide radicals (O2-) predominantly contributed to the removal of cephalexin. With the addition of HCO3- (1-5 mM) or Suwannee River natural organic matter (SRNOM, 2-10 mg L-1), the k values were substantially decreased by a factor of 1.8-70 to 1.69 × 10-3-6.67 × 10-2 min-1, probably due to screening effect of HCO3- or SRNOM sorbed on ZnO nanowires and scavenging of free radicals by free HCO3- or SRNOM in solution. Combining product identification by mass spectrometry and molecular computation, cephalexin photodegradation pathways were identified, including hydroxylation, demethylation, decarboxylation, and dealkylation. Overall, the novel ZnO nanowires have the potential to be used for removing antibiotics from contaminated waters.


Assuntos
Antibacterianos/química , Cefalexina/química , Nanofios/química , Luz Solar , Poluentes Químicos da Água/química , Purificação da Água/métodos , Óxido de Zinco/química , Catálise , Cinética , Nanofios/efeitos da radiação , Fotólise , Rios , Óxido de Zinco/efeitos da radiação
14.
Carbohydr Polym ; 217: 15-25, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31079671

RESUMO

A bifunctional interfacial layer was introduced onto the surface of cotton fabric which not only enhanced the interfacial bonding between Ag@ZnO and organic substrates but also improved the photocatalytic performance simultaneously. In detail, a modified cotton fabric (denoted as Cot-g-Si/Ag@ZnO) was fabricated through radiation-induced graft polymerization of γ-methacryloxypropyl trimethoxysilane and followed the in-situ formation of ZnO and loading of Ag nanoparticles simultaneously. Owing to ZnOSi between the graft chains and Ag@ZnO photocatalyst, the charge carrier concentration increased and Ag was prevented from oxidizing through the partial separation from ZnO, leading to enhanced near-field amplitudes of the localized surface plasmon resonance. Cot-g-Si/Ag@ZnO also exhibited excellent photocorrosion resistance, photostability and laundering durability. Its photocatalytic activity was fully maintained after several photodegradation cycles; moreover, after laundering durability test, the photocatalytic activity was improved compared with the newly prepared one. Credible mechanism for the photocatalytic activity of Cot-g-Si/Ag@ZnO under sunlight irradiation is proposed.


Assuntos
Antibacterianos/farmacologia , Fibra de Algodão , Nanopartículas Metálicas/química , Siloxanas/farmacologia , Prata/química , Óxido de Zinco/farmacologia , Antibacterianos/química , Antibacterianos/efeitos da radiação , Catálise , Escherichia coli/efeitos dos fármacos , Gossypium/química , Luz , Nanopartículas Metálicas/efeitos da radiação , Azul de Metileno/efeitos da radiação , Fotólise , Rodaminas/efeitos da radiação , Siloxanas/química , Siloxanas/efeitos da radiação , Prata/efeitos da radiação , Staphylococcus aureus/efeitos dos fármacos , Óxido de Zinco/química , Óxido de Zinco/efeitos da radiação
15.
ACS Sens ; 4(4): 1081-1089, 2019 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-30912423

RESUMO

Breath analysis has been considered a noninvasive, safe, and reliable way to diagnose cancer at very early stage. Rapid detection of cancer volatile markers in breath samples via a portable sensing device will lay the foundation of future early cancer diagnosis. Nevertheless, unsatisfactory sensitivity and specificity of these sensing devices restrain the clinical application of breath analysis. Herein, we proposed the strategy of designing the light-regulated electrochemical reaction assisted core-shell heterostructure to address the issue of concern; that is, the photoactive shell will be designed for trigging the light-regulated electrochemical reaction and enhancing the sensitivity while a catalytic active core will play the function of removing interference gases. After screening of various core candidates, Fe2O3 was found to exhibit relatively low conversion rate to 3-methylhexane, which is one of the representative volatile markers for breath analysis, suggesting that mutual interference would be eliminated by Fe2O3. Based on this assumption, an electrochemical sensor comprising core-shell Fe2O3@ZnO-SE (vs Mn-based RE) was fabricated and sensing properties to 6 kinds of volatile markers was evaluated. Interestingly, the thickness of ZnO shell significantly influenced the response behavior; typically, the Fe2O3@ZnO with shell thickness of 4.8 nm offers the sensor high selectivity to 3-methylhexane. In contrast, significantly mutual response interference is observed for the Fe2O3@ZnO with extremely thick/thin shell. Particularly, sensing properties are greatly enhanced upon illumination; a detection limit to 3-methylhexane can even be as low as 0.072 ppm which will be useful in clinic application. Besides, the high selectivity of the sensor to 3-methylhexane is further confirmed by the testing of simulated breath samples. In summary, we anticipate that the strategy proposed in this research will be a starting point for artificially tailoring the sensitivity and selectivity of future sensing devices.


Assuntos
Testes Respiratórios/métodos , Técnicas Eletroquímicas/métodos , Compostos Férricos/química , Compostos Orgânicos Voláteis/análise , Óxido de Zinco/química , Biomarcadores Tumorais/análise , Humanos , Luz , Limite de Detecção , Óxido de Zinco/efeitos da radiação
16.
J Environ Sci (China) ; 79: 54-66, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30784464

RESUMO

Novel 3D biogenic C-doped Bi2MoO6/In2O3-ZnO Z-scheme heterojunctions were synthesized for the first time, using cotton fiber as template. The as-prepared samples showed excellent adsorption and photodegradation performance toward the hazardous antibiotic doxycycline under simulated sunlight irradiation. The morphology, phase composition and in situ carbon doping could be precisely controlled by adjusting processing parameters. The carbon doping in Bi2MoO6/In2O3-ZnO was derived from the cotton template, and the carbon content could be varied in the range 0.9-4.4 wt.% via controlling the heat treatment temperature. The sample with Bi2MoO6/In2O3-ZnO molar ratio of 1:2 and carbon content of 1.1 wt.% exhibited the highest photocatalytic activity toward doxycycline degradation, which was 3.6 and 4.3 times higher than those of pure Bi2MoO6 and ZnInAl-CLDH (calcined layered double hydroxides), respectively. It is believed that the Z-scheme heterojunction with C-doping, the 3D hierarchically micro-meso-macro porous structure, as well as the high adsorption capacity, contributed significantly to the enhanced photocatalytic activity.


Assuntos
Alumínio/química , Bismuto/química , Carbono/química , Índio/química , Molibdênio/química , Óxido de Zinco/química , Adsorção , Alumínio/efeitos da radiação , Antibacterianos/química , Carbono/efeitos da radiação , Fibra de Algodão , Doxiciclina/química , Índio/efeitos da radiação , Molibdênio/efeitos da radiação , Fotólise , Luz Solar , Óxido de Zinco/efeitos da radiação
17.
Chemosphere ; 208: 698-706, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29894971

RESUMO

With the development of nanotechnology, nanomaterials have been widely applied in anti-bacterial coating, electronic device, and personal care products. NanoZnO is one of the most used materials and its ecotoxicity has been extensively studied. To explore the potential phototoxicity of nanoZnO induced by visible light, we conducted a long-term experiment on litter decomposition of Typha angustifolia leaves with assessment of fungal multifaceted natures. After 158 d exposure, the decomposition rate of leaf litter was decreased by nanoZnO but no additional effect by visible light. However, visible light enhanced the inhibitory effect of nanoZnO on fungal sporulation rate due to light-induced dissolution of nanoZnO. On the contrary, enzymes such as ß-glucosidase, cellobiohydrolase, and leucine-aminopeptidase were significantly increased by the interaction of nanoZnO and visible light, which led to high efficiency of leaf carbon decomposition. Furthermore, different treatments and exposure time separated fungal community associated with litter decomposition. Therefore, the study provided the evidence of the contribution of visible light to nanoparticle phototoxicity at the ecosystem level.


Assuntos
Ecossistema , Água Doce , Luz , Nanopartículas/toxicidade , Typhaceae/microbiologia , Óxido de Zinco/toxicidade , Bactérias , Carbono/farmacologia , Fungos/efeitos dos fármacos , Folhas de Planta/química , Folhas de Planta/microbiologia , Óxido de Zinco/efeitos da radiação
18.
Water Res ; 139: 281-290, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29656193

RESUMO

Both nanoparticulate (nZnO and nTiO2) and organic chemical ultraviolet (UV) filters are active ingredients in sunscreen and protect against skin cancer, but limited research exists on the environmental effects of sunscreen release into aquatic systems. To examine the trade-offs of incorporating nanoparticles (NPs) into sunscreens over the past two decades, we targeted endpoints sensitive to the potential risks of different UV filters: solar reactive oxygen production in water and disruption of zebrafish embryo development. First, we developed methodology to extract nanoparticles from sunscreens with organic solvents. Zebrafish embryos exposed to parts-per-million NPs used in sunscreens displayed limited toxicological effects; nZnO particles appeared to be slightly more toxic than nTiO2 at the highest concentrations. In contrast, seven organic UV filters did not affect zebrafish embryogenesis at or near aqueous solubility. Second, to simulate potent photo-initiated reactions upon release into water, we examined methylene blue (MB) degradation under UV light. nTiO2 from sunscreen caused 10 times faster MB loss than nZnO and approached the photocatalytic degradation rate of a commercial nTiO2 photocatalysts (P25). Organic UV filters did not cause measurable MB degradation. Finally, we estimated that between 1 and 10 ppm of sunscreen NPs in surface waters could produce similar steady state hydroxyl radical concentrations as naturally occurring fluvic acids under sunlight irradiation. Incorporation of NPs into sunscreen may increase environmental concentrations of reactive oxygen, albeit to a limited extent, which can influence transformation of dissolved substances and potentially affect ecosystem processes.


Assuntos
Nanopartículas/toxicidade , Compostos Orgânicos/toxicidade , Protetores Solares/toxicidade , Titânio/toxicidade , Poluentes Químicos da Água/toxicidade , Óxido de Zinco/toxicidade , Animais , Ecossistema , Embrião não Mamífero/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Nanopartículas/química , Nanopartículas/efeitos da radiação , Compostos Orgânicos/química , Compostos Orgânicos/efeitos da radiação , Espécies Reativas de Oxigênio/química , Protetores Solares/química , Protetores Solares/efeitos da radiação , Titânio/química , Titânio/efeitos da radiação , Raios Ultravioleta , Poluentes Químicos da Água/química , Poluentes Químicos da Água/efeitos da radiação , Peixe-Zebra , Óxido de Zinco/química , Óxido de Zinco/efeitos da radiação
19.
Appl Radiat Isot ; 137: 56-61, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29571037

RESUMO

64Cu is one of the most beneficial radionuclide that can be used as a theranostic agent in Positron Emission Tomography (PET) imaging. In this current work, 64Cu was produced with zinc oxide nanoparticles (natZnONPs) and zinc oxide powder (natZnO) via the 64Zn(n,p)64Cu reaction in Tehran Research Reactor (TRR) and the activity values were compared with each other. The theoretical activity of 64Cu also was calculated with MCNPX-2.6 and the cross sections of this reaction were calculated by using TALYS-1.8, EMPIRE-3.2.2 and ALICE/ASH nuclear codes and were compared with experimental values. Transmission Electronic Microscopy (TEM), Scanning Electronic Microscopy (SEM) and X-Ray Diffraction (XRD) analysis were used for samples characterizations. From these results, it's concluded that 64Cu activity value with nanoscale target was achieved more than the bulk state target and had a good adaptation with the MCNPX result.


Assuntos
Radioisótopos de Cobre , Radioimunodetecção/métodos , Nanomedicina Teranóstica/métodos , Radioisótopos de Cobre/química , Humanos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/efeitos da radiação , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Tomografia por Emissão de Pósitrons/métodos , Pós , Compostos Radiofarmacêuticos/química , Difração de Raios X , Óxido de Zinco/química , Óxido de Zinco/efeitos da radiação
20.
J Hazard Mater ; 347: 378-389, 2018 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-29407847

RESUMO

Sunlight mediated photo-degradation and anti-bacterial activity of hetero junctioned plasmonic binary (Au/ZnO, RGO/ZnO) and ternary (RGO/Au/ZnO) nanocomposites (NC) have been reported. Higher photo-charge carrier generation, increased charge separation, improved active sites for catalysis, enhanced LSPR and larger photo-response regions have been achieved. Decoration with Au nanoparticles (ca. 11 ±â€¯3 and 48 ±â€¯5 nm) and RGO of ZnO (3D/1D) microstructures (aspect ratio 15.18) provides ternary NCs an edge over mono/bi component catalysts. The ternary NC have shown improved dye degradation capacity with 100% efficiency (5 µM MB solution) and average adsorption degradation capacity (Q°) of 83.34 mg/g within 30 min of sunlight exposure (900 ±â€¯30 Wm-2). Elaborated studies by varying reaction parameters like initial dye concentration, contact time, type of NCs and initial loading of NCs reveals pseudo first order degradation kinetics. 100% microbial killing of Gram positive S.aureus strain with 60 µg/ml of NC using sunlight as activator has proven the simultaneous multiple functionality of the NC. Further, facile green one pot hydrothermal synthesis with water as reaction medium, absence of photo-corrosion of NCs, regeneration ability (ca. 90% for 10 µM solution) of NCs, projects a broader potential application of the synthesized NCs and could reduce the continuous requirement of such material, limiting the environmental toxicity.


Assuntos
Ouro , Grafite , Nanocompostos , Óxido de Zinco , Catálise , Corantes/química , Ouro/administração & dosagem , Ouro/química , Ouro/efeitos da radiação , Grafite/administração & dosagem , Grafite/química , Grafite/efeitos da radiação , Azul de Metileno/química , Nanocompostos/administração & dosagem , Nanocompostos/química , Nanocompostos/efeitos da radiação , Nanocompostos/ultraestrutura , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/efeitos da radiação , Luz Solar , Poluentes Químicos da Água/química , Purificação da Água/métodos , Óxido de Zinco/administração & dosagem , Óxido de Zinco/química , Óxido de Zinco/efeitos da radiação
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