Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 225
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
ACS Appl Mater Interfaces ; 13(40): 47784-47792, 2021 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-34585581

RESUMEN

Indium gallium zinc oxide (IGZO) is one of the most promising materials for diverse optoelectronic applications based on thin-film transistors (TFTs) including ultraviolet (UV) photodetectors. In particular, the monitoring of UV-A (320-400 nm) exposure is very useful for healthcare applications because it can be used to prevent various human skin and eye-related diseases. However, the relatively weak optical absorption in the UV-A range and the persistent photoconductivity (PPC) arising from the oxygen vacancy-related states of IGZO thin films limit efficient UV monitoring. In this paper, we report the enhancement of the UV photoresponse characteristics of IGZO photo-TFTs by the surface functionalization of biomolecules on an IGZO channel. The biomaterial/IGZO interface plays a crucial role in enhancing UV-A absorption and suppressing PPC under negative gate bias, resulting in not only increased photoresponsivity and specific detectivity but also a fast and repeatable UV photoresponse. In addition, turning off the device without external bias completely eliminates PPC due to the internal electric field induced by the surface functionalization of biomaterials. Such a volatile feature of PPC enables the fast and repeatable UV photoresponse. These results suggest the potential of IGZO photo-TFTs combined with biomaterials for real-time UV monitoring.


Asunto(s)
Óxidos/química , Transistores Electrónicos , Rayos Ultravioleta , Técnicas Electroquímicas/instrumentación , Técnicas Electroquímicas/métodos , Galio/química , Galio/efectos de la radiación , Indio/química , Indio/efectos de la radiación , Proteínas Luminiscentes/química , Proteínas Luminiscentes/efectos de la radiación , Óxidos/efectos de la radiación , Compuestos de Zinc/química , Compuestos de Zinc/efectos de la radiación
2.
ACS Appl Mater Interfaces ; 13(24): 28650-28661, 2021 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-34124895

RESUMEN

Novel and effective radiosensitizers that can enhance radiosensitivity of tumor tissues and increase the local radiation dose are highly desirable. In this work, templated by bovine serum albumin (BSA), Bi2Se3-MnO2 nanocomposites (Bi2Se3-MnO2@BSA) were fabricated via biomineralization, while Bi2Se3 nanodots act as radiosensitizers to increase the local radiation dosage because of their strong X-ray attenuation ability, and MnO2 with catalase-like activity can increase the oxygen concentration in tumors by triggering the decomposition of tumor endogenous H2O2 so as to improve the hypoxia-associated radioresistance of tumors. Owing to the interaction of the two components in the interface, Bi2Se3-MnO2@BSA showed promoted catalytic activity compared to MnO2@BSA, favoring tumor radiotherapy (RT) sensitization. BSA templating enabled the nanocomposites with high colloidal stability and biocompatibility as well as satisfactory tumor targeting both in vitro and in vivo; thus, an enhanced RT efficacy was obtained. Moreover, the proposed Bi2Se3-MnO2@BSA exhibited excellent performances in computerized tomography and magnetic resonance imaging. Thus, this work provides a tumor microenvironment-responsive multifunctional theranostic nanoagent with an improved performance for imaging-guided tumor RT sensitization.


Asunto(s)
Antineoplásicos/uso terapéutico , Bismuto/uso terapéutico , Compuestos de Manganeso/uso terapéutico , Nanocompuestos/uso terapéutico , Neoplasias/tratamiento farmacológico , Óxidos/uso terapéutico , Fármacos Sensibilizantes a Radiaciones/uso terapéutico , Compuestos de Selenio/uso terapéutico , Animales , Antineoplásicos/síntesis química , Antineoplásicos/efectos de la radiación , Bismuto/química , Catálisis/efectos de la radiación , Bovinos , Línea Celular Tumoral , Medios de Contraste/síntesis química , Medios de Contraste/efectos de la radiación , Medios de Contraste/uso terapéutico , Femenino , Células Endoteliales de la Vena Umbilical Humana , Humanos , Peróxido de Hidrógeno/química , Peróxido de Hidrógeno/metabolismo , Compuestos de Manganeso/química , Compuestos de Manganeso/efectos de la radiación , Ratones Endogámicos BALB C , Nanocompuestos/química , Nanocompuestos/efectos de la radiación , Neoplasias/diagnóstico por imagen , Óxidos/química , Óxidos/efectos de la radiación , Oxígeno/metabolismo , Medicina de Precisión , Fármacos Sensibilizantes a Radiaciones/síntesis química , Fármacos Sensibilizantes a Radiaciones/efectos de la radiación , Compuestos de Selenio/química , Compuestos de Selenio/efectos de la radiación
3.
ACS Appl Mater Interfaces ; 13(26): 31066-31076, 2021 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-34137247

RESUMEN

The serious problem of pharmaceutical and personal care product pollution places great pressure on aquatic environments and human health. Herein, a novel coating photocatalyst was synthesized by adhering Ag-AgCl/WO3/g-C3N4 (AWC) nanoparticles on a polydopamine (PDA)-modified melamine sponge (MS) through a facile layer-by-layer assembly method to degrade trimethoprim (TMP). The formed PDA coating was used for the anchoring of nanoparticles, photothermal conversion, and hydrophilic modification. TMP (99.9%; 4 mg/L) was removed in 90 min by the photocatalyst coating (AWC/PDA/MS) under visible light via a synergistic photocatalytic-photothermal performance route. The stability and reusability of the AWC/PDA/MS have been proved by cyclic experiments, in which the removal efficiency of TMP was still more than 90% after five consecutive cycles with a very little mass loss. Quantitative structure-activity relationship analysis revealed that the ecotoxicities of the generated intermediates were lower than those of TMP. Furthermore, the solution matrix effects on the photocatalytic removal efficiency were investigated, and the results revealed that the AWC/PDA/MS still maintained excellent photocatalytic degradation efficiency in several actual water and simulated water matrices. This work develops recyclable photocatalysts for the potential application in the field of water remediation.


Asunto(s)
Nanopartículas/química , Trimetoprim/química , Catálisis/efectos de los fármacos , Grafito/química , Grafito/efectos de la radiación , Indoles/química , Indoles/efectos de la radiación , Luz , Nanopartículas/efectos de la radiación , Compuestos de Nitrógeno/química , Compuestos de Nitrógeno/efectos de la radiación , Óxidos/química , Óxidos/efectos de la radiación , Polímeros/química , Polímeros/efectos de la radiación , Plata/química , Plata/efectos de la radiación , Compuestos de Plata/química , Compuestos de Plata/efectos de la radiación , Temperatura , Triazinas/química , Triazinas/efectos de la radiación , Tungsteno/química , Tungsteno/efectos de la radiación , Purificación del Agua/métodos
4.
Chemosphere ; 262: 128082, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33182100

RESUMEN

As important natural oxidants and adsorbents, manganese (Mn) oxide minerals affect the speciation, bioavailability and fate of pollutants and nutrient elements. It was found that birnessite-type Mn(IV) oxide minerals can be formed in the presence of NO3- and solar irradiation. However, the photochemical formation and transformation processes from Mn2+ to Mn(IV) oxide minerals remain unclear. In this work, the Mn(IV) oxide minerals were confirmed to be photochemically formed mainly due to the disproportionation of Mn(III) intermediates generated from the oxidation of Mn2+ in the presence of NO3- under UV light irradiation. The oxidation rate of Mn2+ to Mn(IV) oxide minerals decreased with increasing initial Mn2+ concentration due to the lower disproportionation rate. The increase in NO3- concentration, pH and temperature promoted Mn2+ photochemical oxidation. The photochemical formation rate of Mn(IV) oxide minerals increased with increasing ligand concentrations at low ligand concentrations. Ligands affected the formation of Mn(IV) oxide minerals by promoting the formation and reducing the reactivity of Mn(III) intermediates. Overall, this work reveals the important role of Mn(III) intermediates in the formation of natural Mn oxide minerals.


Asunto(s)
Compuestos de Manganeso/química , Manganeso/química , Minerales/química , Óxidos/química , Luz Solar , Manganeso/efectos de la radiación , Compuestos de Manganeso/efectos de la radiación , Minerales/efectos de la radiación , Modelos Teóricos , Oxidación-Reducción , Óxidos/efectos de la radiación , Procesos Fotoquímicos , Temperatura
5.
J Mater Chem B ; 8(36): 8356-8367, 2020 09 23.
Artículo en Inglés | MEDLINE | ID: mdl-32794542

RESUMEN

The integration of advanced diagnostic contrast agents with versatile therapeutic drugs is an effective method for cancer treatment. However, combining various biocompatible theranostic modalities into a single platform at the nanoscale is a challenging assignment. In this work, we report a simple chemical synthetic route for producing a homogeneous hybrid nanoflower shaped morphology based on Au@Mn3O4 magneto-plasmonic nanomaterials. The synthetic mechanism of the nanoflowers is well-matched with the heteroepitaxial growth phenomena by which the nano-petals of Mn3O4 generated on the surface of the Au core. The food and drug administration (FDA) in the USA approved the use of triblock polymer Pluronic F-127 to enhance the biocompatibility of Au@Mn3O4 hybrid nanoflowers. The prepared hybrid nanoflowers produce a significant photothermal heating effect with a thermal transduction efficiency of 38%, comparable to the nanorods and nanoparticles of gold (Au). The hybrid junction reveals promising optical and magnetic properties and the prepared Au@Mn3O4 nanoflowers not only exhibit strong near-infrared (NIR) absorption to produce excellent photothermal efficacy under irradiation with an 808 nm NIR laser, but also demonstrate a significant T1-weighted magnetic resonance (MR) image enhancement in vitro and in vivo. The histopathology assessments indicate only negligible toxicity of the nanoflowers to major organs. Therefore, the hybrid Au@Mn3O4 nanoflowers exhibit great potential in T1-weighted MR-imaging and photothermal therapy, opening up new possibilities for synthesizing novel bio-compatible, homogeneous, and shape controllable nanostructures with multifunctional applications.


Asunto(s)
Medios de Contraste/uso terapéutico , Nanopartículas del Metal/uso terapéutico , Neoplasias/diagnóstico por imagen , Neoplasias/tratamiento farmacológico , Animales , Línea Celular Tumoral , Medios de Contraste/síntesis química , Medios de Contraste/efectos de la radiación , Femenino , Oro/química , Oro/efectos de la radiación , Oro/uso terapéutico , Rayos Infrarrojos , Imagen por Resonancia Magnética/métodos , Compuestos de Manganeso/química , Compuestos de Manganeso/efectos de la radiación , Compuestos de Manganeso/uso terapéutico , Nanopartículas del Metal/química , Nanopartículas del Metal/efectos de la radiación , Ratones Desnudos , Óxidos/química , Óxidos/efectos de la radiación , Óxidos/uso terapéutico , Terapia Fototérmica/métodos , Nanomedicina Teranóstica
6.
Anal Chim Acta ; 1125: 299-307, 2020 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-32674777

RESUMEN

As a broad-spectrum tetracycline antibiotic, the overuse of oxytetracycline (OTC) causes antibiotics residues in the environment and seriously threats to human health owing to effective antibacterial properties. Thus, it is particularly important to design a photoelectrochemical (PEC) aptasensor to detect OTC with excellent performance. Herein, we developed a selective and stable PEC aptasensor of OTC on the basis of Co3O4 nanoparticles (Co3O4 NPs)/graphitic carbon nitride (g-CN) heterojunction, used as PEC active materials. The Co3O4 NPs were successfully grown on the g-CN via grinding and calcining mixture of Co3O4 precursors and bulk g-CN. The Co3O4/g-CN heterojunction with improved light utilization and promoted electrons/holes separation capability can exhibit higher PEC signal than that of g-CN. In order to implement the purpose of specific recognition, OTC-aptamer was introduced into modified electrode to construct highly selective PEC aptasensor for OTC determination, which can possess wide linear range (0.01-500 nM) with low detection limit (3.5 pM, S/N = 3). This PEC aptasensor platform with excellent selectivity and high stability can provide a practical application in the field of water monitoring.


Asunto(s)
Aptámeros de Nucleótidos/química , Técnicas Biosensibles/métodos , Técnicas Electroquímicas/métodos , Nanopartículas del Metal/química , Oxitetraciclina/análisis , Fotoquímica/métodos , Secuencia de Bases , Cobalto/química , Cobalto/efectos de la radiación , Grafito/química , Grafito/efectos de la radiación , Luz , Límite de Detección , Nanopartículas del Metal/efectos de la radiación , Compuestos de Nitrógeno/química , Compuestos de Nitrógeno/efectos de la radiación , Óxidos/química , Óxidos/efectos de la radiación , Oxitetraciclina/química , Reproducibilidad de los Resultados , Ríos/química , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/química
7.
ACS Appl Mater Interfaces ; 12(17): 19357-19368, 2020 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-32275133

RESUMEN

Local surface plasmon resonance (LSPR)-enhanced catalysis has brought a substantial amount of opportunities across various disciplines such as photocatalysis, photodetection, and photothermal therapeutics. Plasmon-induced photothermal and hot carriers effects have also been utilized to activate the enzyme-like reactions. Compared with natural enzymes, the relatively low catalytic performance of nanozymes severely hampered the potential applications in the field of biomedicine. For these issues mentioned above, herein, we demonstrate a highly efficient sulfite oxidase (SuOx) mimetic performance of plasmonic monolayer MoOx (ML-MoOx) upon LSPR excitation. We also established that the considerable photothermal effect and the injection of hot carriers induced by LSPR are responsible for promoting the SuOx activity of ML-MoOx. The high transient local temperature on the surface of ML-MoOx generated by the photothermal effect facilitates to impact the reaction velocity and feed the SuOx-like activity, while the generation of hot carriers which are suggested as predominant effects catalyzes the oxidation of sulfite to sulfate through significantly decreasing the activation energy for the SuOx-like reaction. These investigations present a contribution to the basic understanding of plasmon-enhanced enzyme-like reaction and provided an insight into the optimization of the SuOx mimetic performance of nanomaterials.


Asunto(s)
Molibdeno/química , Óxidos/química , Sulfitos/química , Catálisis/efectos de la radiación , Calor , Rayos Infrarrojos , Cinética , Modelos Químicos , Molibdeno/efectos de la radiación , Oxidación-Reducción , Óxidos/síntesis química , Óxidos/efectos de la radiación , Sulfatos/síntesis química , Sulfito-Oxidasa/química , Resonancia por Plasmón de Superficie
8.
J Hazard Mater ; 393: 122366, 2020 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-32120212

RESUMEN

Thin 2D/2D WO3/g-C3N4 Step-scheme (S-scheme) heterojunction with carbon doping and bridge (C-W/N) was constructed with anionic polyacrylamide (APAM), in which APAM functioned as an assistant templet and a carbon source. APAM and WO3 were inserted into g-C3N4 nanosheet. The carbon, thin planar structure and WO3 with oxygen vacancies result in fast charge transfer, high quantum efficiency and strong driving force for photocatalytic reaction. Consequently, as-prepared C-W/N ternary composite photocatalyst exhibited significantly enhanced photocatalytic performance for tetracycline (TC) degradation under visible light compared to pure g-C3N4, WO3 and other binary composites. Moreover, the material showed high stability and reusability in cyclic TC degradation. The principal intermediate products over C-W/N photocatalyst were revealed by HPLC-MS analysis. Corresponding degradation pathway of TC was also presented in this work. According to the trapping experiments, analysis of electron spin resource (ESR) and band gap, possible charge transfer pathways of C-W/N are proposed and discussed in detail. Based on the results, carbon derived from APAM works not only as electron mediator but also as acceptor for photocatalytic degradation reaction. It is a promising way to further modulate heterojunction for varies applications.


Asunto(s)
Resinas Acrílicas/química , Grafito/química , Compuestos de Nitrógeno/química , Óxidos/química , Tetraciclina/química , Tungsteno/química , Catálisis/efectos de la radiación , Contaminantes Ambientales/química , Grafito/efectos de la radiación , Luz , Compuestos de Nitrógeno/efectos de la radiación , Óxidos/efectos de la radiación , Tungsteno/efectos de la radiación
9.
J Hazard Mater ; 390: 122158, 2020 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-32004762

RESUMEN

In this study, MoS2/ZnSnO3 (MS-ZSO) composite photocatalyst with loading MS nanosheets onto the surface of porous ZSO microcubes was synthesized using a simple hydrothermal route. The prepared MS-ZSO composite can be easily excited under visible light, and 3 % MS-ZSO exhibits an outstanding photo-degradation (>80 % in 60 min) and mineralization performance (>42 % in 60 min) of the tetracycline. A remarkable improvement in the photocatalytic activity of MS-ZSO composite derived from a positive synergistic effect of well-matched energy level positions, increasement the absorption of visible light, prolonged life time decay and improved interfacial charge transfer between MS and ZSO. In-depth investigation on charge carrier separation mechanism toward MS/ZSO composite under visible light was proposed, which was further evidenced by capture experiments and electron spin resonance (ESR) techniques. Furthermore, the corresponding intermediates of tetracycline degradation over MS-ZSO composites were inspected by liquid chromatography-mass spectrometry (LC-MS) analysis, and the possible degradation paths were proposed.


Asunto(s)
Antibacterianos/química , Disulfuros/efectos de la radiación , Luz , Molibdeno/efectos de la radiación , Nanoestructuras/efectos de la radiación , Óxidos/efectos de la radiación , Tetraciclina/química , Compuestos de Estaño/efectos de la radiación , Compuestos de Zinc/efectos de la radiación , Catálisis , Disulfuros/química , Molibdeno/química , Nanoestructuras/química , Óxidos/química , Procesos Fotoquímicos , Compuestos de Estaño/química , Compuestos de Zinc/química
10.
J Hazard Mater ; 390: 122050, 2020 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-32007859

RESUMEN

In this paper, in-situ fabrication of tungsten oxide (WO3) on carbon nano-tube (CNT) was performed via sol-gel/hydrothermal method to prepare WO3/CNT nanocomposites and then coupled with visible light and ultrasound (US) irradiations for sono-photocatalytic removal of tetracycline (TTC) and pharmaceutical wastewater treatment. The as-prepared catalysts were characterized by FT-IR, XRD, TEM, UV-VIS DRS, FESEM, EDS, TGA, BET, BJH, EIS, and EDX techniques. The characterization tests, indicated successful incorporation of CTNs into the WO3 framework and efficient reduction of charge carries recombination rate after modifying with CNT. The investigation of experimental parameters verified that 60 mg/L TTC could be perfectly degraded at optimum operational parameters (WO3/CNT: 0.7 g/L, pH: 9.0, US power: 250 W/m2, and light intensity: 120 W/m2 over 60 min treatment. Trapping experiments results verified that HO radicals and h+ were the main oxidative species in degradation of TTC. The as-prepared photocatalysts could be reused after six successive cycles with an approximately 8.8 % reduction in removal efficiency. Investigation of the effect of real pharmaceutical wastewater revealed that this system is able to eliminate 83.7 and 90.6 % of TOC and COD, respectively after 220 min of reaction time. Some compounds with lower toxic impact and molecular weight, compared to raw pharmaceutical wastewater, were detected after treatment by sono-photocatalysis process. The biodegradability of real pharmaceutical wastewater was improved significantly after treatment by WO3/CNT sono-photocatalysis.


Asunto(s)
Antibacterianos/química , Luz , Nanotubos de Carbono/efectos de la radiación , Óxidos/efectos de la radiación , Tetraciclina/química , Tungsteno/efectos de la radiación , Ondas Ultrasónicas , Contaminantes Químicos del Agua/química , Catálisis , Industria Farmacéutica , Residuos Industriales , Nanocompuestos/química , Nanocompuestos/efectos de la radiación , Nanotubos de Carbono/química , Óxidos/química , Procesos Fotoquímicos , Tungsteno/química , Aguas Residuales , Purificación del Agua/métodos
12.
Sci Rep ; 9(1): 9927, 2019 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-31289314

RESUMEN

The ability to manipulate the structure and function of promising systems via external stimuli is emerging with the development of reconfigurable and programmable multifunctional materials. Increasing antifungal and antitumor activity requires novel, effective treatments to be diligently sought. In this work, the synthesis, characterization, and in vitro biological screening of pure α-Ag2WO4, irradiated with electrons and with non-focused and focused femtosecond laser beams are reported. We demonstrate, for the first time, that Ag nanoparticles/α-Ag2WO4 composite displays potent antifungal and antitumor activity. This composite had an extreme low inhibition concentration against Candida albicans, cause the modulation of α-Ag2WO4 perform the fungicidal activity more efficient. For tumor activity, it was found that the composite showed a high selectivity against the cancer cells (MB49), thus depleting the populations of cancer cells by necrosis and apoptosis, without the healthy cells (BALB/3T3) being affected.


Asunto(s)
Antifúngicos/farmacología , Antineoplásicos/farmacología , Candida albicans/efectos de los fármacos , Electrones , Nanopartículas del Metal/química , Óxidos/química , Plata/química , Tungsteno/química , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Animales , Apoptosis , Células 3T3 BALB , Proliferación Celular , Humanos , Nanopartículas del Metal/administración & dosificación , Nanopartículas del Metal/efectos de la radiación , Ratones , Óxidos/efectos de la radiación , Plata/efectos de la radiación , Células Tumorales Cultivadas , Tungsteno/efectos de la radiación , Neoplasias de la Vejiga Urinaria/patología , Ensayos Antitumor por Modelo de Xenoinjerto
13.
J Hazard Mater ; 377: 227-236, 2019 09 05.
Artículo en Inglés | MEDLINE | ID: mdl-31170571

RESUMEN

Herein, a heterostructure based on MnO2 and g-C3N4 was constructed on the surface of metallic Ti implants, in which MnO2 favored the transfer and separation of free charges to enhance the photoconversion efficiency of g-C3N4 by 21.11%. Consequently, the yield of ROS was promoted significantly, which denatured protein and damaged DNA to kill bacteria efficiently. In addition, glutathione (GSH, l-γ-glutamyl-l-cysteinyl-glycine) defending oxidative stress in bacteria, was oxidized by MnO2 in the hybrid coating once the bacterial membrane was disrupted by ROS. Hence, after visible light irradiation for 20 min, MnO2/g-C3N4 coating exhibited superior disinfection efficacy of 99.96% and 99.26% against S. aureus and E. coli severally. This work provided a practical sterilization strategy about MnO2/g-C3N4 systems through the synergistic effects of enhanced photodynamic antibacterial therapy and oxidization effect of MnO2 with great biosafety, in which MnO2 enhanced the photocatalyst property of g-C3N4 to generate more ROS and deplete GSH to improve antibacterial efficiency. It will bring more insight into rapid and highly effective disinfection and antibacterial strategy without using traditional high-temperature, ultraviolet ray and antibiotics that cause side-effects.


Asunto(s)
Grafito/química , Compuestos de Manganeso/química , Compuestos de Nitrógeno/química , Óxidos/química , Procesos Fotoquímicos , Esterilización/métodos , Bacterias/metabolismo , Bacterias/efectos de la radiación , Catálisis , Membrana Celular/metabolismo , Membrana Celular/efectos de la radiación , Daño del ADN , Escherichia coli/efectos de la radiación , Glutatión/metabolismo , Grafito/efectos de la radiación , Luz , Compuestos de Manganeso/efectos de la radiación , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Compuestos de Nitrógeno/efectos de la radiación , Óxidos/efectos de la radiación , Especies Reactivas de Oxígeno , Staphylococcus aureus/metabolismo , Staphylococcus aureus/efectos de la radiación
14.
J Hazard Mater ; 375: 161-173, 2019 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-31055193

RESUMEN

A novel Z-scheme system, Ag/ZnFe2O4/Ag/BiTa1-xVxO4 with enhanced electron transfer capacity was constructed for degrading sulfanilamide (SAM) using solar light. The photocatalytic activity of Ag/ZnFe2O4/Ag/BiTa1-xVxO4 was investigated. The effects of the mass ratio (ZnFe2O4:BiTaO4), doped V dose, Ag wt.% content, and irradiation time on the catalytic performance were evaluated. The reasonable mechanism of Ag/ZnFe2O4/Ag/BiTa1-xVxO4 solar photocatalytic degradation was also presented. These results reveal Ag/ZnFe2O4/Ag/BiTa1-xVxO4 possesses enhanced photocatalytic performance. The loaded Ag as electron mediator increases the electron transfer rate. Particularly, the doped V and the Fe ions from ZnFe2O4 form a powerful electron driving force, which enhances the electron transfer capacity. Ag/ZnFe2O4/Ag/BiTa1-xVxO4 shows optimal photocatalytic performance at 2.0 wt.% Ag and 0.5% doped V dose (ZnFe2O4:BiTaO4 = 1.0:0.5). Also, Ag/ZnFe2O4/Ag/BiTa1-xVxO4 exhibits high stability and repeatability in photocatalytic degradation. Several active species (•OH, •O2-, and h+) are produced in the Z-scheme photodegradation of SAM. These results on the enhanced photocatalytic activity of Ag/ZnFe2O4/Ag/BiTa1-xVxO4 are ascribed to synergistic photocatalytic effects of ZnFe2O4 and BiTa1-xVxO4 mediated through Ag and driven by doped V and Fe ions. Therefore, the Z-scheme Ag/ZnFe2O4/Ag/BiTa1-xVxO4 photocatalytic technology proves to be promising for the solar photocatalytic treatment of antibiotics under solar light.


Asunto(s)
Antibacterianos/química , Compuestos Férricos , Metales Pesados , Nanocompuestos , Óxidos , Sulfanilamida/química , Compuestos de Zinc , Catálisis , Compuestos Férricos/química , Compuestos Férricos/efectos de la radiación , Metales Pesados/química , Metales Pesados/efectos de la radiación , Nanocompuestos/química , Nanocompuestos/efectos de la radiación , Oxidación-Reducción , Óxidos/química , Óxidos/efectos de la radiación , Fotólisis , Luz Solar , Compuestos de Zinc/química , Compuestos de Zinc/efectos de la radiación
15.
J Environ Sci (China) ; 79: 161-173, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30784441

RESUMEN

Although manganese oxides are known for their semiconductor characteristics, the photocatalytic performance of conducting polymer intercalated K-Birnessite (K-Bi) has not been explored till date. With the view to design a visible light driven organic-inorganic hybrid photocatalyst for rapid degradation of Bisphenol A (BPA), the present work reports the ultrasound-assisted green synthesis of K-Bi/polypyrrole (Ppy) nanohybrids. The loading of Ppy in K-Bi was confirmed by thermogravimetric analysis while the formation of organic-inorganic hybrid was confirmed by infrared spectroscopy. K-Bi revealed a band gap of 2.8 eV while for the nanohybrids it was found to be ranging between 2.4 and 1.6 eV. X-ray diffraction studies confirmed partial intercalation of Ppy chains in the inter-layer space of K-Bi. High resolution transmission electron microscopy and scanning electron microscopy studies showed mixed morphology of K-Birnessite/Ppy nanohybrids. Rapid degradation of BPA was observed under visible irradiation in presence of K-Bi/Ppy nanohybrids and almost 90% degradation of 20 mg/L BPA solution was achieved within 120 min. The degradation was found to follow pseudo-first order kinetics and the degraded fragments were identified using liquid chromatography-mass spectrometry. Degradation pathway was proposed based on density-functional theory calculations of fukui index predicting the radical easy-attacking (f0) and (f-) sites in BPA.


Asunto(s)
Compuestos de Bencidrilo/química , Disruptores Endocrinos/química , Nanoestructuras/efectos de la radiación , Óxidos/efectos de la radiación , Fenoles/química , Polímeros/efectos de la radiación , Pirroles/efectos de la radiación , Contaminantes Químicos del Agua/química , Catálisis , Luz , Nanoestructuras/química , Óxidos/química , Fotólisis , Polímeros/química , Pirroles/química , Ondas Ultrasónicas , Eliminación de Residuos Líquidos
16.
Radiat Prot Dosimetry ; 186(1): 88-93, 2019 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-30649472

RESUMEN

In this work, we report some preliminary results regarding the analysis of electron spin resonance (ESR) response of soda-lime samples used for retrospective dosimetry. Six different soda-lime glass batches were evaluated after irradiation. We compared several dose reconstruction techniques: saturation method, subtraction method and g-effective, geff, approach. The differences were observed and discussed. ESR signal responses of soda-lime glass samples to different radiation doses for the triage application were investigated. Results confirmed that geff approach has potential for the identification and dosimetry of irradiated soda-lime glass samples using either additive dose method or only calibration curve.


Asunto(s)
Compuestos de Calcio/efectos de la radiación , Espectroscopía de Resonancia por Spin del Electrón/métodos , Espectroscopía de Resonancia por Spin del Electrón/estadística & datos numéricos , Vidrio/efectos de la radiación , Óxidos/efectos de la radiación , Radiometría/métodos , Hidróxido de Sodio/efectos de la radiación , Triaje/métodos , Compuestos de Calcio/química , Relación Dosis-Respuesta en la Radiación , Rayos gamma , Vidrio/química , Humanos , Óxidos/química , Hidróxido de Sodio/química
17.
Int J Pharm ; 557: 66-73, 2019 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-30580088

RESUMEN

Graphene oxide (GO) owns huge surface area and high drug loading capacity for aromatic molecules, such as doxorubicin (DOX). However, its biocompatibility is poor and it might agglomerate in physiological conditions. Chemical modification of GO with hydrophilicpolymer, especially PEGylation, was a common method to improve its biocompatibility. But the chemical modification of GO was complicated, and its drug loading capacity might be reduced because of the occupation of its functional groups. In this study, DOX-PEG polymers with different PEG molecular weights were synthesized to modify nano graphene oxide (NGO) to simultaneously realize the solubilization of NGO and the high loading capacity of DOX. The result showed that the drug release of NGO@DOX-PEG was pH sensitive. NIR irradiation could augment the drug release, cellular uptake, cytotoxicity and nuclear translocation of nanodrugs. Among the three kinds of nanodrugs, NGO@DOX-PEG5K was superior to others. It suggested that after conjugating with PEG, the bond between DOX-PEG and NGO was weakened, which resulted in a better drug release and treatment effect. In summary, the NIR and pH dual-responsive NGO@DOX-PEG nanodrugs were developed by noncovalent modification, and it demonstrated excellent biocompatibility and photochemical therapeutic effect, presenting a promising candidate for antitumor therapy, especially NGO@DOX-PEG5K.


Asunto(s)
Antibióticos Antineoplásicos/administración & dosificación , Doxorrubicina/administración & dosificación , Portadores de Fármacos/administración & dosificación , Grafito/administración & dosificación , Nanopartículas/administración & dosificación , Óxidos/administración & dosificación , Polietilenglicoles/administración & dosificación , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/efectos de la radiación , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Doxorrubicina/química , Doxorrubicina/efectos de la radiación , Portadores de Fármacos/química , Portadores de Fármacos/efectos de la radiación , Liberación de Fármacos , Grafito/química , Grafito/efectos de la radiación , Células HeLa , Humanos , Luz , Nanopartículas/química , Nanopartículas/efectos de la radiación , Óxidos/química , Óxidos/efectos de la radiación , Fotoquimioterapia , Polietilenglicoles/química , Polietilenglicoles/efectos de la radiación , Especies Reactivas de Oxígeno/metabolismo , Solubilidad
18.
Analyst ; 143(20): 4967-4973, 2018 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-30225468

RESUMEN

A multifunctional nanosystem, which integrates biosensing, bioimaging, and therapeutic functions into a single nanoprobe, is of great significance for biosensing and biomedicine. Near-infrared (NIR) graphene quantum dots (GQDs) have emerged as an attractive bioimaging and therapy tool for exploring biological events because they can provide deep imaging penetration and low fluorescence background and produce 1O2 for PDT. Here, we reported a GQD-based multifunctional two-photon nanoprobe for intracellular tumor-related glutathione (GSH) detection and enhanced photodynamic therapy by reducing GSH levels in cancer cells. By taking the excellent quenching property of MnO2 nanosheets and the reduction ability of GSH, a GQD@MnO2 nanoprobe was developed through adsorption of MnO2 nanosheets onto the surface of GQDs for sensing intracellular tumor-related GSH. The nanoprobe shows a highly sensitive response to GSH in aqueous solutions with a detection limit of 83 nM. It also exhibits a high selectivity toward GSH relative to other biomolecules and electrolytes. In addition, once endocytosed, the MnO2 nanosheets are reduced by intracellular GSH, simultaneously releasing GQDs and decreasing the level of GSH for highly efficient PDT.


Asunto(s)
Glutatión/análisis , Glutatión/metabolismo , Grafito/farmacología , Fármacos Fotosensibilizantes/farmacología , Puntos Cuánticos/química , Animales , Fluorescencia , Grafito/química , Grafito/efectos de la radiación , Grafito/toxicidad , Células HeLa , Humanos , Concentración de Iones de Hidrógeno , Límite de Detección , Compuestos de Manganeso/química , Compuestos de Manganeso/farmacología , Compuestos de Manganeso/efectos de la radiación , Microscopía Confocal/métodos , Microscopía Fluorescente/métodos , Óxidos/química , Óxidos/farmacología , Óxidos/efectos de la radiación , Óxidos/toxicidad , Fotones , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/efectos de la radiación , Fármacos Fotosensibilizantes/toxicidad , Puntos Cuánticos/efectos de la radiación , Puntos Cuánticos/toxicidad , Ratas
19.
J Hazard Mater ; 360: 481-489, 2018 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-30144767

RESUMEN

Photocatalytic ozonation has great potential in wastewater treatment. However, the role of ozone and the contribution of photogenerated hole in this process have not been fully understood. Here three WO3 materials are synthesized and used as model catalysts in visible-light photocatalytic ozonation for the mineralization of pharmaceutical pollutants. A dual role of ozone in this process has been confirmed: (i) direct oxidation of the pollutant till formation of refractory intermediates, (ii) efficient trapping of photoelectron that cannot be captured by O2. The latter is crucial because it not only induces the O3--mediated pathway for hydroxyl radical (OH) formation but also separates the hole which has proven to be capable of oxidizing water into OH. Evidenced by photoluminescence results, the intrinsic charge separation ability of WO3 in photocatalytic ozonation is no more as important as that in photocatalysis with O2. Finally, this process is more applicable under acidic condition. This work contributes to a better understanding of the significance of ozone in WO3 photocatalytic ozonation and provides us an insight into the mechanism of photocatalytic ozonation.


Asunto(s)
Oxidantes/química , Óxidos/química , Ozono/química , Preparaciones Farmacéuticas/química , Tungsteno/química , Contaminantes Químicos del Agua/química , Catálisis , Luz , Óxidos/efectos de la radiación , Fotólisis , Tungsteno/efectos de la radiación , Purificación del Agua/métodos
20.
Ecotoxicol Environ Saf ; 163: 620-628, 2018 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-30096663

RESUMEN

Nanosized BaFe1-xCuxO3 powders were prepared using the Pechini method. To limit grain growth and agglomeration, the temperature of calcination was limited to 800 °C. For all samples, the cubic form of BaFeO2.75 was predominant with minor additional phases. Cu doping was found to have a remarkable effect on the structural cubic unit cell parameter as the Cu concentration increased. As shown by XRD,the samples were in the nanometer size range (17-63 nm). However, as the Cu concentration increases, the agglomeration increases with the highest surface area for the BaFe0.95Cu0.05O3 composition, which also displays the highest photocatalytic atrazine degradation. For this sample, more than 90% degradation of atrazine was obtained at the optimum conditions (120 min irradiation under visible light at pH 11 using 0.75 mg of the catalyst). The Atrazine degradation was found to follow the pseudo-order kinetics. GC/MS was used to detect the intermediates and the reaction pathways. All the prepared samples and produced waters at the end of the experiment were found to be nontoxic.


Asunto(s)
Atrazina/efectos de la radiación , Herbicidas/efectos de la radiación , Luz , Óxidos/química , Atrazina/química , Catálisis , Herbicidas/química , Cinética , Óxidos/efectos de la radiación , Fotólisis , Temperatura
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA