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Recently, global-scale efforts have been conducted for the electroreduction of CO2 as a potentially beneficial pathway for the conversion of greenhouse gases to useful chemicals and renewable fuels. This study focuses on the development of selective and sustainable electrocatalysts for the reduction of aqueous CO2 to CO. A RuIIcomplex [Ru(tptz)(ACN)Cl2] (RCMP) (tptz = 2,4,6-tris(2-pyridyl)-1,3,5-triazine, ACN = acetonitrile) was prepared as a molecular electrocatalyst for the CO2 reduction reaction in an aqueous solution. Density functional theory-calculated frontier molecular orbitals suggested that the tptz ligand plays a key role in dictating the electrocatalytic reactions. The RCMP electrocatalyst was grafted onto the graphene oxide (GO) surface both noncovalently (GO/RCMP) and covalently (GO-RCMP). The field emission scanning electron microscopy and elemental distribution analyses revealed the homogeneous distribution of the complex onto the GO sheet. The photoluminescence spectra confirmed accelerated charge-transfer in both nanohybrids. Compared to the bare complex, the GO-RCMP and GO/RCMP nanohybrids showed enhanced electrocatalytic activity, achieving >95% and 90% Faradaic efficiencies for CO production at more positive onset potentials, respectively. The GO-RCMP nanohybrid demonstrated outstanding electrocatalytic activity with a current of â¼84 µA. The study offers a perspective on outer- and inner-sphere electron-transfer mechanisms for electrochemical energy conversion systems.
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Herein, the α-Bi2O3 nanocrystal decorated by nitrogen dopant and its heterojunction nanocomposite with g-C3N4 (N0.1/Bi2O3/g-C3N4) is successfully fabricated for the first time, for photo-oxidation of RhB and photo-reduction of Cr(VI) to Cr(III). The resulting N0.1/Bi2O3/g-C3N4 (3%) nanocomposite showed an optimal Cr(VI) photo-reduction and RhB photo-oxidation rates under visible-light irradiation, being 3-4 times higher than that of pure α-Bi2O3. The results from XPS confirmed the substitution of nitrogen with various oxidation states from N3+ to Nx+ (x < 5), due to the existence of different nitrogen oxides including N-O, O-N=O, and NO3- in the crystal structure. We investigated the reaction mechanism using catalytic tests, impedance spectroscopy, EPR technique, and density functional calculations. The DFT calculations presented the appearance of a new mid-gap hybrid of p states, comprised of N 2p, O 2p, and Bi 6P states, which enhance light absorption capacity and narrow band gap. The theoretical results were in excellent agreement with experimental UV-Vis data. The N0.1/Bi2O3/g-C3N4 nanocomposite exhibited acceptable practical application value and recycling ability for removal of the contaminants. Such improved photocatalytic activity is originated from the modified band positions, new electron evolution pathway, introducing defects in α-Bi2O3 by insertion of N atoms into the Bi sites, and the enhanced charge carrier mobility between N0.1/Bi2O3 and g-C3N4. The strategy to form nitrogen-doped bismuth-based nanocomposites may open a new opportunity to design atomic-level electronic defects by feasible methods to obtain a versatile photocatalyst material with simultaneous photo-reduction and photo-oxidation ability for removal of Cr(VI) and organic dyes from water.
Asunto(s)
Bismuto , Nitrógeno , Catálisis , Luz , Oxidación-ReducciónRESUMEN
Application of amino acids-immobilized porous materials for drug delivery studies has been attracted a lot of attention in the recent years. In this study, amino acids-grafted graphene foams were prepared by anchoring of Alanine (Ala), Cysteine (Cys) and Glycine (Gly) amino acids on the surface of graphene oxide (GO) nanostructures and used as the novel biocompatible carriers to control releasing of the cisplatin as the cytotoxic anticancer drug. The characterization of prepared compounds was done by the FT-IR, Raman, TGA, N2 adsorption-desorption isotherms, SEM, and TEM techniques. Adsorption and in vitro release behavior of amino acids-functionalized foams were studied using ICP standard method. The results show that the drug loading amount and the drug releasing rate are significantly enhanced upon functionalization process. The Ala-Foam sample with the larger surface area and pore volume showed a higher loading content (4.53%) than other samples. In addition, the MTT test on the two MCF-7 and HepG2 human cancer cell lines exhibited an acceptable biocompatibility and sustainable drug releasing from the carriers up to 48 h, leading to the dosage frequency decrease and the patient compliance improvement.
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Grafito , Aminoácidos , Cisplatino , Preparaciones de Acción Retardada , Portadores de Fármacos , Objetivos , Humanos , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
TiO2 is one of the most widely used semiconductors for photocatalytic reactions. However, its wide bandgap energy and fast charge recombination limit its catalytic activity. Thus, herein, a new Ru(ii) polypyridyl complex, [Ruii(tptz)(CH3CN)Cl2] (tptz = 2,4,6-tris(2-pyridyl)-1,3,5-triazine), was synthesized and used as a visible-light photosensitizer dye for improving the light harvesting and quantum efficiency of TiO2. Accordingly, a well-designed nanostructured photocatalyst was proposed using mesoporous TiO2 nanocrystals coupled with reduced graphene oxide (rGO) and the polypyridyl Ru(ii) complex, which was tested for the photocatalytic degradation of atrazine (ATZ) as a model of emerging water contaminants. Specifically, the Ru complex (Ru-CMP) served as an electron donor, while rGO acted as an electron acceptor, and the synergistic effect between them promoted the separation of electron-hole pairs and suppressed the charge recombination in the hybridized species. Structural analysis indicated that the TiO2 nanoparticles with an anatase crystal structure had a mesoporous texture and were homogeneously coated on the rGO sheets. The detailed FT-IR, Raman, XPS and UV-vis absorption spectroscopic analyses combined with EDS mapping clearly confirmed the successful loading of the Ru complex onto the catalyst. The PL and EIS results revealed that the addition of the Ru-CMP photosensitizer enhanced the charge separation and transport. The gas-phase geometry and energies of the molecular orbitals of the Ru complex were evaluated via DFT calculations. The results from the DFT calculations were consistent with the experimental results. Compared to pure TiO2, the as-synthesized Ru-CMP-TiO2/rGO hybrid exhibited significantly enhanced photocatalytic activity for the degradation of ATZ. The rate of ATZ degradation in the developed photocatalytic process with the Ru-CMP-TiO2/rGO hybrid was 9 times that with commercial TiO2. The enhanced photocatalytic activity of the prepared catalyst can be attributed to its better light harvesting and efficient electron transportation due to its more suitable LUMO position than the conduction band of TiO2. Moreover, the excellent conductivity and adsorption capacity of graphene contributed to the increase in photocatalytic activity. Thus, these features make the Ru-CMP-TiO2/rGO hybrid nanomaterial an excellent candidate for the photocatalytic purification of contaminated water.
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Herein, a series of new amino acid-functionalized hollow mesoporous silica nanospheres (HMSNs) by post-grafting methods were prepared. These new materials were characterized by different techniques and were studied as matrices for the antineoplastic drug (cisplatin) transport and delivery. The results demonstrate that the surface functionalization of the carriers has a remarkable positive influence on the loading efficiency and release rate of cisplatin. The highest drug entrapment efficiency and the most optimal release properties were observed when the (2-(butylamino) ethyl) glycine groups are grafted on the HMSNs surface (AFS-2-HMSNs sample). Moreover, the in vitro cytotoxic effect of both empty and cisplatin-loaded AFS-2-HMSNs sample (CDDP@AFS-2-HMSNs) on MCF-7 cells (human breast adenocarcinoma cell line) and HepG2 cells (human liver carcinoma cell line) were evaluated by MTT assay. The most important outcome is that the empty carrier revealed no cytotoxicity to cancer cells. However, CDDP@AFS-2-HMSNs caused a notable inhibition of cell viability which was affected from the dose and time. Our results demonstrate that the synthesized materials could be used as carriers for drug delivery with controlled release applications.
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Aminoácidos/administración & dosificación , Antineoplásicos/administración & dosificación , Cisplatino/administración & dosificación , Portadores de Fármacos/administración & dosificación , Nanosferas/administración & dosificación , Dióxido de Silicio/administración & dosificación , Aminoácidos/química , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cisplatino/química , Preparaciones de Acción Retardada/administración & dosificación , Preparaciones de Acción Retardada/química , Portadores de Fármacos/química , Liberación de Fármacos , Células Hep G2 , Humanos , Células MCF-7 , Nanosferas/química , Porosidad , Dióxido de Silicio/químicaRESUMEN
Pollution of water resources by antibiotics is a growing environmental concern. In this work, nanocomposites of g-C3N4@Ni-Ti layered double hydroxides (g-C3N4@Ni-Ti LDH NCs) with high surface areas were synthesized through an optimized hydrothermal method, in the presence of NH4F. Application of various characterization techniques unraveled that the prepared nanocomposites are composed of porous Ni-Ti LDH nanoparticles and hierarchical g-C3N4 nanosheets. Further, these NCs were employed for photocatalytic and sonophotocatalytic removal of amoxicillin (AMX), as a model antibiotic, from aqueous solutions. In addition, sonocatalysis was performed. It was found out that the g-C3N4@Ni-Ti LDH NCs outperform their pure g-C3N4 and Ni-Ti LDH components in photocatalytic degradation of AMX under visible light irradiation. Also, the following order was determined for efficiency of the three adopted processes: sonocatalysis < photocatalysis < sonophotocatalysis. Furthermore, variation of the sonophotocatalysis conditions specified 500 W light intensity, 9 s on/1 s off ultrasound pulse modem and 1.25 g/L g-C3N4-20@Ni-Ti LDH as the optimal conditions. In this way, optimization of the highly efficient sonophotocatalytic process resulted in 99.5% AMX degradation within 75 min. Moreover, a TOC analyzer was employed to estimate the rate of AMX degradation over the nanocomposites. In addition, formation of hydroxyl radicals (â¢OH) on the surface of the g-C3N4-20@Ni-Ti LDH particles was approved using the terephthalic acid probe in photoluminescence (PL) spectroscopy. No significant loss was observed in the sonophotocatalytic activity of the nanocomposites even after five consecutive runs. Also, a plausible mechanism was proposed for the sonophotocatalysis reaction. In general, our findings can be considered as a starting point for synthesis of other g-C3N4-based NCs and application of the resultant nanocomposites to environmental remediation.
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Antibacterianos/química , Hidróxidos/química , Nanoestructuras/química , Níquel/química , Nitrilos/química , Titanio/química , Catálisis , Tamaño de la Partícula , Procesos Fotoquímicos , Propiedades de SuperficieRESUMEN
In this study, various sonochemical conditions were applied to prepare the microsheets, nanosheets and nanoflowers of a metal-organic framework (MOF; [Zn6(IDC)4(OH)2(Hprz)2]n) that is composed of Zn(II) cations coordinated with the linear N-donor piperazine (prz) and rigid planar imidazole-4,5-dicarboxylate (H3IDC) ligands. The PXRD patterns approved purity of the samples and the FT-IR spectra related the detected bonds and functional groups to [Zn6(IDC)4(OH)2(Hprz)2]n crystals. The morphological results indicated that any changes in the synthesis conditions can affect nucleation and morphology of the nanostructures. The prepared MOF nanosheets and nanoflowers (with particle size average of 95 and 116 nm, respectively) were employed to adsorb the ampicillin, amoxicillin and cloxacillin antibiotics. Then, the MOFs were calcined at 550 â and atmospheric pressure to produce ZnO nanoparticles and the resultant nanoparticles were adopted to photodegrade the antibiotics. These nanoparticles can photodegrade 37% of the amoxicillin compounds within 180 min. Among the examined samples, the nanoflowers demonstrated the highest adsorption capacity by eliminating 92.5%, 88% and 89% of the antibiotic molecules from the 60-ppm amoxicillin, ampicillin and cloxacillin solutions, respectively. Also, these nanoflowers are thermally stable up to 365 â. The associated adsorption process was found to follow pseudo-first-order kinetics, in the case of amoxicillin.
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Antibacterianos/química , Estructuras Metalorgánicas/química , Nanoestructuras , Contaminantes Químicos del Agua/química , Adsorción , Soluciones , Ondas UltrasónicasRESUMEN
At ambience temperature, a facile and large-scale sonochemical synthesis route was used to synthesize graphitic carbon nitride@[Ti4C24H39N3O29] metal-organic framework nanocomposites (g-C3N4-X@YTi-MIL125-NH2 NCs, where X and Y stood for the weight percentages of g - C3N4 and the synthesis method of Ti-MIL125-NH2, respectively) having 2-Amino-1,4-benzenedicarboxylic acid (2-ATA) ligand with amine functional free groups. The obtained NCs were characterized by FT-IR, PXRD, FE-SEM, BET, UV-DRS, PL, EIS, and zeta potential. Moreover, g-C3N4-X@YTi-MIL125-NH2 capability to eliminate 4-nitrophenol (4-NP) contaminant from water via visible light illumination was explored. Our synthesized NCs under a facile, green ultrasonic technique (i.e. g-C3N4-30@STi-MIL125-NH2) had a higher percentage of degradation than those from hydrothermal technique (i.e. g-C3N4-30@HTi-MIL125-NH2) with degradation percentages of 75% and 57%, respectively, which resulted in effective mass transfer and separation of photo - generated charge carriers. Additionally, this higher percentage of degradation could be attributed to the larger surface area and unique morphology of the ultrasonically synthesized particles with higher homogeneity and better and non-agglomerated distribution. Furthermore, excellent reusability and stability were observed for g-C3N4-30@STi-MIL125-NH2. We also explored the role of some scavengers in the degradation procedures to investigate the effect of active species. The experimental results were used to describe the suggested mechanism capability for improved photocatalysis.
RESUMEN
In this work, a bio-metal-organic framework (Bio-MOF) coated with a monodispersed layer of chitosan (CS; CS/Bio-MOF) was synthesized and applied as a pH-responsive and target-selective system for delivery of doxorubicin (DOX) in the treatment of breast cancer. The efficiency of the nanocarrier in loading and releasing DOX was assessed at different pH levels. To monitor the in vitro drug release behavior of the drug-loaded carrier, the carrier was immersed in a phosphate buffered saline solution (PBS, pH 7.4) at 37 °C. According to the observations, the nanocarrier presents a slow and continuous release profile as well as a noticeable drug loading capacity. In addition, the carrier demonstrates a pH-responsive and target-selective behavior by releasing a high amount of DOX at pH 6.8, which is indicative of tumor cells and inflamed tissues and releasing a substantially lower amount of DOX at higher pH values. In addition, the results indicated that pH is effective on DOX uptake by CS/Bio-MOF. A 3.6 mg amount of DOX was loaded into 10 mg of CS/Bio-MOF, resulting in a 21.7% removal at pH 7.4 and 93.0% at pH 6.8. The collapsing and swelling of the CS layers coated on the surface of the Bio-MOFs were found to be responsible for the observed pH dependence of DOX delivery. Moreover, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the trypan blue test were performed on the MCF-7 (breast cancer) cell line in the presence of the CS/Bio-MOF carrier to confirm its biological compatibility. In addition, Annexin V staining was conducted to evaluate the cytotoxicity of the free and loaded DOX molecules. On the basis of the obtained optical microscopy, MTT assay, fluorescence microscopy, and dyeing results, the CS/Bio-MOF carrier greatly enhances cellular uptake of the drug by the MCF-7 cells and, therefore, apoptosis of the cells due to its biocompatibility and pH-responsive behavior.
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Antibióticos Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Quitosano/química , Doxorrubicina/metabolismo , Portadores de Fármacos/química , Liberación de Fármacos , Estructuras Metalorgánicas/química , Nanoestructuras/química , Antibióticos Antineoplásicos/síntesis química , Antibióticos Antineoplásicos/química , Apoptosis/efectos de los fármacos , Neoplasias de la Mama/patología , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Doxorrubicina/química , Doxorrubicina/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Humanos , Concentración de Iones de Hidrógeno , Células MCF-7 , Estructuras Metalorgánicas/síntesis química , Estructuras Metalorgánicas/farmacología , Tamaño de la Partícula , Relación Estructura-Actividad , Propiedades de SuperficieRESUMEN
One of the major challenges in photodegradation of organic dyes is designing a visible light active and highly efficient photocatalyst that can degrade both cationic and anionic dyes. To design such an ideal catalyst, this work synthesized graphitic-C3N4@NiAl layered double hydroxide nanocomposites (g-C3N4@NiAl-LDH NCPs) with various g-C3N4 contents through a convenient and high-yield method. The photocatalytic process was optimized by evaluating the impacts of type of dye (cationic and anionic), photocatalyst dosage, pH, and contact time. According to the results, the photocatalytic performance of g-C3N4@NiAl-LDH NCPs in degradation of cationic and anionic dyes is more noticeable than the photocatalytic activities of its discrete components. The observed improvement in the photocatalytic performance of the g-C3N4@NiAl-LDH NCPs can be attributed to the intimacy of their contact interfaces and a synergistic effect between pristine g-C3N4 and NiAl-LDH, which results in effective mass transfer and separation of photogenerated charge carriers. The impact of some charge scavengers on the process was evaluated to define the role of each active species and propose a possible photodegradation mechanism. The g-C3N4@Ni-Al LDH NCPs could be reused for four cycles without any significant loss in efficiency.
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Using a green and simple route with ultrasound illumination under atmospheric pressure and at room temperature, the nanosized preparation of a Zn(II) metal-organic framework, [Zn(ATA)(BPD)]∞ (ATAâ¯=â¯2-aminoterephthalic acid), BPDâ¯=â¯1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene), having nano-plate shape and 3D channel framework, was considered and the product was named as compound 1. The X-ray diffraction (XRD), scanning electron microscopy (SEM), IR spectroscopy, Brunauer-Emmett-Teller (BET), and thermogravimetric analysis (TGA) were used for characterization of the synthesized micro/nano-structures. Further, impact of different sonication times and initial reagent contents on the shape and size of the micro/nano-structures was investigated. The results show that under ultrasound irradiation non-aggregated plates with uniform morphology can be obtained with content of [0.0125] M of the initial reagents in the presence of triethylamine (TEA) at 120â¯min. Moreover, through N2 adsorption, effect of the preparation route on the porosity was explored. The bulk and nano-plates of compound 1 were also studied for adsorption of 2,4-dichlorophenol as a pollutant sample. Kinetic studies indicated that 2,4-dichlorophenol adsorption via MOF nano-plates are of first-order kinetics. Also, MOF nano-plates have significantly been reutilized for five times while their adsorption properties have remained unchanged.
RESUMEN
In this work, a magnetic bio-metal-organic framework (MBMOF) nanocomposite with porous-layer open morphology is synthesized through a simple sonochemical approach and its effects on Leishmania major (MRHO/IR/75/ER) under both in vitro and in vivo conditions are investigated. The effects of sonication time, initial concentration of reagents and sonication power on size and morphology of MBMOF nanocomposites have been investigated and optimized. A comparison was then made between the structural information of the nanostructures and that of the bio-metal-organic framework crystals. Using the powder X-ray diffraction (PXRD), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), energy dispersive analysis of X-ray (EDAX), vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA), and Brunauer-Emmet-Teller (BET) techniques, the prepared MBMOF nanocomposites were characterized. The mean numbers of promastigotes (cell/ml) in different MBMOF concentrations (3.12, 6.25, 12.5, 25, 50, 100, 200 and 400⯵gâ¯mL-1) were determined by direct counting after 24, 48 and 72â¯h. Using MTT assays, the cytotoxic impacts of the MBMOF nanocomposites on promastigotes, intracellular amastigotes, and J774 macrophages were estimated. In order to investigate their therapeutic effects, the prepared MBMOF nanocomposites (25 and 12.5⯵gâ¯mL-1) were used as ointment three times a week to treat Leishmania major in BALB/c mice. The lesion size and weight of mice were assessed before and during the treatment. The parasitic loads were measured in spleen and liver through the culture. After 72â¯h, the INF-γ and IL-4 cytokines levels in the supernatant of the spleen culture were measured. To the best of the authors' knowledge, this study is the first to attempt to synthesize the bio-MOFs through an in-situ sonosynthesis route under ultrasound irradiation and examine their cytotoxicity effects on Leishmania major under in vitro and in vivo conditions.
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Leishmania major/efectos de los fármacos , Nanopartículas de Magnetita/química , Compuestos Orgánicos/química , Ondas Ultrasónicas , Animales , Línea Celular , Modelos Animales de Enfermedad , Femenino , Interferón gamma/metabolismo , Interleucina-4/metabolismo , Leishmaniasis Cutánea/tratamiento farmacológico , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/parasitología , Macrófagos/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Compuestos Orgánicos/farmacología , Compuestos Orgánicos/uso terapéutico , Difracción de Polvo , Espectrometría por Rayos X , Espectroscopía Infrarroja por Transformada de Fourier , Bazo/efectos de los fármacos , Bazo/metabolismo , Bazo/parasitología , TermogravimetríaRESUMEN
Herein, we report isolation of the AlTMP2 gene from the halophytic C4 grass Aeluropus littoralis. The subcellular localization suggested that AlTMP2 is a plasma membrane protein. In A. littoralis exposed to salt and osmotic stresses, the AlTMP2 gene was induced early and at a high rate, but was upregulated relatively later in response to abscisic acid and cold treatments. Expression of AlTMP2 in tobacco conferred improved tolerance against salinity, osmotic, H2O2, heat, and freezing stresses at the germination and seedling stages. Under control conditions, no growth or yield penalty were mentioned in transgenic plants due to the constitutive expression of AlTMP2. Interestingly, under greenhouse conditions, the seed yield of transgenic plants was significantly higher than that of non-transgenic (NT) plants grown under salt or drought stress. Furthermore, AlTMP2 plants had less electrolyte leakage, higher membrane stability, and lower Na+ and higher K+ accumulation than NT plants. Finally, six stress-related genes were shown to be deregulated in AlTMP2 plants relative to NT plants under both control and stress conditions. Collectively, these results indicate that AlTMP2 confers abiotic stress tolerance by improving ion homeostasis and membrane integrity, and by deregulating certain stress-related genes.
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Nicotiana/genética , Plantas Modificadas Genéticamente/genética , Poaceae/genética , Presión OsmóticaRESUMEN
A visible light-driven amine-functionalized Al-based MOF#@ yxSm2O3-ZnO nanocomposite (NH2-MOF#@ yxSm2O3-ZnO NCP) was synthesized as an effective photocatalyst for AMX degradation in the presence of ultrasound, in which # is MOF synthesis conditions from MOFI to MOFXII and x and y stand for the weight percentages of Sm2O3-to-ZnO and Sm2O3-ZnO-to-MOF, respectively. The ß-lactam antibiotic AMX, which is widely used for treating Gram-positive and Gram-negative bacterial infections in both animals and humans, was employed as a model pollutant. Using different detection techniques, the synthesized materials were characterized. Furthermore, effects of different synthesis methods, ultrasonic time, precursor concentration, sonication amplitude, and modulators on the MOFs photocatalytic behavior were taken into account. Also, catalytic dose and recycling, H2O2 usage, and operating pH effects were investigated. Compared to the pure forms of NH2-MOF-53(Al) and Sm2O3-ZnO, the NCPs having the optimal Sm2O3-ZnO and NH2-MOF-53(Al) contents highly influenced the photocatalytic activity due to the synergetic impacts of the high charge mobility and the red shift in the NH2-MOF@Sm2O3-ZnO NCPs absorption edge compared to the Sm2O3-ZnO nanoflowers. We used a TOC analyzer, UV/vis spectroscopy, and HPLC chromatogram to estimate the rate of AMX elimination in water over NH2-MOFXII@307Sm2O3-ZnO NCPs as our optimal sample. In addition, after the AMX pollutant degradation, the NH2-MOF@Sm2O3-ZnO NCPs were structurally stable and maintained the majority of their photocatalytic properties even after five runs of recycling process The NH2-MOFXII@307Sm2O3-ZnO NCPs as the superior photocatalysts were more examined and a mechanism for the AMX degradation was suggested. As a suggestion, our obtained results can be used as a starting point for the preparation of the other heterogeneous MOF-based NCPs combined with the Sm2O3-ZnO for a variety of applications such as the environmental remediation.
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In this study, under a sonochemical method, a 3D, porous Zn(II)-based metal-organic framework [Zn(TDC)(4-BPMH)]n·n(H2O) is produced, which is called compound 1. To this end, the dicarboxylate linker of TDC, (2,5-thiophene dicarboxylic acid) and the pillar spacer of 4-BPMH, (N,N-bis-pyridin-4-ylmethylene-hydrazine) were employed. Moreover, variations in the morphology and growth of the micro/nanoparticles of compound 1 were investigated in terms of the effect of temperature, ultrasound irradiation power, sonication time, initial reagent concentrations, and pyridine concentration as a modulator. DFT model was used to examine the sonication effect on the distribution of the pore sizes. Moreover, the preparation method effect on the porosity and removal of two sample pollutants (i.e., 2,4-dichlorophenol (24-DCP) and amoxicillin (AMX)) from wastewater was studied.
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In this study, we have reported a biocompatible metal-organic framework (MOF) with ultra-high surface area, which we have shown to have uses as both a cancer treatment delivery system and for environmental applications. Using a sonochemical approach, highly flexible organic H3BTCTB and ditopic 4,4'-BPDC ligands, along with modulators of acetic acid and pyridine were combined to prepare a Zn(II)-based metal-organic framework, DUT-32, [Zn4O(BPDC)(BTCTB)4/3(DEF)39.7(H2O)11.3]. Powder X-ray diffraction (PXRD), field-emission scanning electron microscopy (FE-SEM), and Fourier transform infrared spectroscopy (FTIR) were used to characterize, the particle size, shape, and structure of the DUT-32. To show the effects of shape and size of DUT-32 micro/nano-structures on doxorubicin (DOX) drug release and amoxicillin (AMX) adsorption, time of sonication, initial reagent concentrations, irradiation frequency, and acetic acid to pyridine molar ratios were optimized. The drug-loaded DUT-32 was soaked in simulated body fluid (SBF) and the drug release ratio was monitored through release time to perform in vitro drug release test. A slow and sustained release was observed for DUT-32 micro/nano-structures, having a considerable drug loading capacity. At the pH values 7.4-4.5, various profiles of pH-responsive release were achieved. Also, the prepared DUT-32 micro/nano-structures are found to be biocompatible with PC3 (prostate cancer) and HeLa (cervical cancer) cell lines, when tested by MTT assay. Moreover, DUT-32 micro/nano-structures were studied to show AMX adsorption from aqueous solution. Finally, kinetic studies indicated that AMX adsorption and drug release of DOX via this MOF are of first-order kinetics.
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Amoxicilina/química , Antineoplásicos/química , Liberación de Fármacos , Estructuras Metalorgánicas/química , Estructuras Metalorgánicas/síntesis química , Sonicación , Agua/química , Ácido Acético/química , Adsorción , Técnicas de Química Sintética , Doxorrubicina/química , Portadores de Fármacos/síntesis química , Portadores de Fármacos/química , Concentración de Iones de Hidrógeno , Cinética , Modelos Moleculares , Conformación Molecular , Piridinas/química , SolucionesRESUMEN
Three different palladium(II) complexes with ligands containing nitrogenized aromatic rings were investigated theoretically as model to obtain the computational band gap energies. The results demonstrated promising possibility for designing palladium(II) complexes with photocatalytic properties at visible light irradiation. Deliberated products were synthesized via grafting on the silica-coated Fe3O4 magnetic nanoparticles (Fe3O4@SiO2). Formation of complexes on the surface of Fe3O4@SiO2, as insoluble and reusable photocatalysts, was proved by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric (TGA), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), transmission electron microscope (TEM), and scanning electron microscopy (SEM) analyses. The trend of the band gap energies of prepared structures was calculated via experimental and theoretical methods. The photocatalytic capability of these nanoparticles was investigated in degradation of 2,4-dichlorophenol by means of HPLC analysis. A tentative reaction mechanism for the formation of intermediates was proposed. Graphical abstract á .
Asunto(s)
Clorofenoles/análisis , Complejos de Coordinación/química , Modelos Teóricos , Paladio/química , Fotólisis , Contaminantes Químicos del Agua/análisis , Bromo/química , Catálisis , Cloro/química , Clorofenoles/efectos de la radiación , Luz , Nanopartículas de Magnetita/química , Nanopartículas/química , Nitrógeno/química , Dióxido de Silicio/química , Termogravimetría , Contaminantes Químicos del Agua/efectos de la radiaciónRESUMEN
Single crystals of new polyoxometalate based ionic crystal [Fe(phen)3]2[SiW12O40]·3DMF (IC-Fe), (phen=1,10-phenanthroline, DMF=N,N-dimethylformamide) and their nanoparticles (IC-Fe-NPs) have been synthesized via self-assembly of constituent ions and sonochemical reaction, respectively. All materials have been characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), thermal gravimetric (TG), powder X-ray diffraction (PXRD), FT-IR spectroscopy and elemental analyses. Effect of sonication conditions on size and morphology of IC-Fe was investigated including time, concentrations of initial reagents and power of irradiation. Further studies have shown that IC-Fe is not only active in photocatalytic degradation of 2,4-dichlorophenol under visible light irradiation, but also is very stable in the various solvents and it can be easily separated and reused for cycles of reaction.
RESUMEN
Graphene oxide-[Zn2(oba)2(bpfb)]·(DMF)5 metal-organic framework nanocomposite (GO-TMU-23; H2oba=4,4'-oxybisbenzoic acid, bpfb=N,N'-bis-(4-pyridylformamide)-1,4-benzenediamine, DMF=N,N-dimethylformamide) is prepared through a simple and large-scale sonochemical preparation method at room temperature. The obtained nanocomposite is characterized by Field Emission Scanning Electron Microscopy (FE-SEM), powder X-ray diffraction (PXRD) and FT-IR spectroscopy. Additionally, the absorption ability of GO-TMU-23 nanocomposite toward cationic dye methylene blue was also performed. Significantly, GO-TMU-23 nanocomposite exhibits remarkably accelerated adsorption kinetics for methylene blue in comparison with the parent materials. The adsorption process shows that 90% of the dye has been removed and the equilibrium status has been reached in 2min by using the nanocomposites as the adsorbent.
RESUMEN
Targeted engineering of microbial genomes holds much promise for diverse biotechnological applications. Transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats/Cas9 systems are capable of efficiently editing microbial genomes, including that of Saccharomyces cerevisiae. Here, we demonstrate the use of TALENs to edit the genome of S. cerevisiae with the aim of inducing the overproduction of fatty acids. Heterodimeric TALENs were designed to simultaneously edit the FAA1 and FAA4 genes encoding acyl-CoA synthetases in S. cerevisiae. Functional yeast double knockouts generated using these TALENs over-produce large amounts of free fatty acids into the cell. This study demonstrates the use of TALENs for targeted engineering of yeast and demonstrates that this technology can be used to stimulate the enhanced production of free fatty acids, which are potential substrates for biofuel production. This proof-of-principle study extends the utility of TALENs as excellent genome editing tools and highlights their potential use for metabolic engineering of yeast and other organisms, such as microalgae and plants, for biofuel production.