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The porous structure of biochar, its large surface area, and its anti-oxidant properties are extensively used for pollutant removal strategies. The literature to date has reported that the biochar assisted metal-oxide core-shells have a dominating degradation ability under solar irradiation. Therefore, this study is significantly focused on cinnamon biochar as an active anti-oxidant agent incorporated in titania-cobalt ferrite nanocore-shell (Biochar/TiO2/CoFe2O4) structures for the first time in wastewater treatment against chlorophenol pollutants. Pure materials, core-shells, and biochar aided composites were synthesized by chemical methods, and their characteristics were analyzed using various instrumentation techniques. The diffraction outcomes of Biochar/TiO2/CoFe2O4 showed the mixed phases containing biochar, TiO2, and CoFe2O4. The morphological characteristics revealed that the biochar creates porosity and a peripheral layer covering the core-shell. Meanwhile, absorption studies of TiO2/CoFe2O4 core-shell and Biochar/TiO2/CoFe2O4 samples achieved 65% and 92% degradation efficiencies when exposed to visible light against chlorophenol pollutants, respectively. All these results confirm the presence of distinct functional groups as well as the combined synergistic effects that activated the charge separation, resulting in the successful destruction of water pollutants. In addition, the highly efficient Biochar/TiO2/CoFe2O4 sample was recycled, and the efficiency was maintained stable for five repeated degradation processes. Thus, Biochar/TiO2/CoFe2O4 will be utilized to expand the possibilities for biofuel generation and energy storage devices.

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The global level of attention has been raised for photocatalytic pollutant removal technologies for degrading organic pollutants because of rising concerns about their toxicity. In this study, NiFe2O4/TiO2 core shells and pure samples of NiFe2O4 and TiO2 were synthesized using the sol-gel process and used to degrade naphthalene which is one among the polycyclic aromatic hydrocarbons (PAHs) pollutant. The synthesized materials were evaluated using a variety of analytical techniques, and the typical NiFe2O4/TiO2 core-shell results showed good purity and a lack of other impurity structures. Through morphological characterization, the core-shell structure of NiFe2O4/TiO2 has been established. However, the activity of visible light degradation was boosted by the generation of hydroxyl radicals after the electron-hole pair was delayed. Additionally, a lower band gap in NiFe2O4/TiO2 than in pure materials promotes photocatalytic activity. Similarly, photocatalytic naphthalene elimination by the core-shell achieved 67% efficiency after 150 min of visible light exposure. Furthermore, the produced core-shell has a high magnetic property, making separation from the photo-irradiated solutions easier; as a result, recycling was likely successful up to three cycles. The photocatalytic mechanism of the NiFe2O4/TiO2 composite was proposed. This research could also be applied to the degradation of other polycyclic aromatic hydrocarbon contaminants.

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In this work, the synthesis of core-shell ordered mesoporous silica nanoparticles (CSMS) with tunable particle size and shape through a dual surfactant-assisted approach is demonstrated. By varying the synthesis conditions, including the type of the solvent and the concentration of the surfactant, monodispersed and ordered mesoporous silica nanoparticles with tunable particle size (140-600 nm) and morphologies (hexagonal prism (HP), oblong, spherical, and hollow-core) can be realized. Comparative studies of the Cabazitaxel (CBZ)-loaded HP and spherical-shaped CSMS are conducted to evaluate their drug delivery efficiency to PC3 (prostate cancer) cell lines. These nanoparticles showed good biocompatibility and displayed a faster drug release at acidic pH than at basic pH. The cellular uptake of CSMS measured using confocal microscopy, flow cytometry, microplate reader, and ICP-MS (inductively coupled plasma mass spectrometry) techniques in PC3 cell lines revealed a better uptake of CSMS with HP morphology than its spherical counterparts. Cytotoxicity study showed that the anticancer activity of CBZ is improved with a higher free radical production when loaded onto CSMS. These unique materials with tunable morphology can serve as an excellent drug delivery system and will have potential applications for treating various cancers.

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InAs-based nanocrystals can enable restriction of hazardous substances (RoHS) compliant optoelectronic devices, but their photoluminescence efficiency needs improvement. We report an optimized synthesis of InAs@ZnSe core@shell nanocrystals allowing to tune the ZnSe shell thickness up to seven mono-layers (ML) and to boost the emission, reaching a quantum yield of ≈70% at ≈900 nm. It is demonstrated that a high quantum yield can be attained when the shell thickness is at least ≈3ML. Notably, the photoluminescence lifetimeshows only a minor variation as a function of shell thickness, whereas the Auger recombination time (a limiting aspect in technological applications when fast) slows down from 11 to 38 ps when increasing the shell thickness from 1.5 to 7MLs. Chemical and structural analyses evidence that InAs@ZnSe nanocrystals do not exhibit any strain at the core-shell interface, likely due to the formation of an InZnSe interlayer. This is supported by atomistic modeling, which indicates the interlayer as being composed of In, Zn, Se and cation vacancies, alike to the In2 ZnSe4 crystal structure. The simulations reveal an electronic structure consistent with that of type-I heterostructures, in which localized trap states can be passivated by a thick shell (>3ML) and excitons are confined in the core.

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The MnBi alloys is a model series of rare-Earth free magnets for surge of technologies of small parts of automobiles, power generators, medical tools, memory systems, and many others. The magnetics stem primarily at unpaired Mn-3d5spins (a 4.23µBmoment) align parallel via an orbital moment 0.27µBof Bi-5d106s2p3in a crystal lattice. Thus, using a surplus Mn (over Bi) in a Mn70Bi30type alloy designs a spin-rich system of duly tailored properties useful for magnetics and other devices. In this view, we report here a strategy of a refined alloy powder Mn70Bi30can grow into small crystals of hexagonal (h) plates at seeds as annealed in magnetic fields (in H2gas). So, small h-plates (30 to 50 nm widths) are grown up at (002) facets, wherein the edges are turned down in a spiral (≤2.1 nm thicknesses) in a core-shell structure. The results are described with x-ray diffraction, lattice images and magnetic properties of a powder Mn70Bi30(milled in glycine) is annealed at 573 K for different time periods, so to the Mn/Bi order at the permeable facets (seeds). Duly annealed samples exhibit an enhanced magnetization,Ms→ 70.8 emu g-1, with duly promoted coercivityHc→ 10.810 kOe (15.910 kOe at 350 K), energy-product 14.8 MGOe, and the crystal-field-anisotropy,K1→ 7.6 × 107erg cm-3, reported at room temperature. Otherwise,Msshould decline at any surplus 3d5-Mn spins order antiparallel at the antisites. Enhanced Curie point 658.1 K (628 K at Mn50Bi50alloy) anticipates that a surplus Mn does favor the Mn-Bi exchange interactions. Proposed spin models well describe the spin-dynamics and lattice relaxations (on anneals) over the lattice volume (with twins) and spin clusters.

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The design of water-stable photo and electrocatalysts of metal-organic frameworks (MOFs) for its promising catalytic applications at long-term irradiations or persisted current loads is extremely necessary but still remains as challenging. A limited number of reports on Ti-MOF-based catalysts for water splitting are only available to explain and understand the correlation between the nature of materials and MOFs array. Herein, spherical Ti-MOFs and corresponding partially annealed hollow core-shell Ti-MOFs (Ti-MOF/D) are designed and the correlation with their photo(electro)catalytic water splitting performance is evaluated. The switchable valence state of Ti for the Ti-MOF as a function of molecular bonding is the possible reason behind the observed photocatalytic hydrogen generation and light-harvesting ability of the system. Besides, the defect state, solid core-shell mesoporous structure, and active sites of Ti-MOF help to trap the charge carriers and the reduction of the recombination process. This phenomenon is absent for hollow core-shells Ti-MOF/D spheres due to the rigid TiO2 outer surface although there is a contradiction in surface area with Ti-MOF. Considering the diversity of Ti-MOF and Ti-MOF/D, further novel research can be designed using this way to manipulate their properties as per the requirements.

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Unlike single-step reactions, multi-step reactions can be greatly facilitated only if all the intermediate reactions can be catalyzed simultaneously and progressively. Herein, the theoretical analysis and experiments to illustrate the superiority of the cascade oxygen evolution reaction (OER) are conducted. As different OER intermediate reactions demand Fex Ni1-x OOH with altered Fe/Ni ratios, gradient Fe-doped NiOOH can be an ideal electrocatalyst for the efficient cascade OER in line. Fine controlling of the nucleation sequence of iron and nickel sulfides leads to a FeS2 @NiS2 core-shell structure. The activated outward diffusion of Fe dopants results in the gradient Fe/Ni ratios in the Fex Ni1-x OOH shell, where a cascade OER can happen. Electrochemical tests suggest that the FeS2 @NiS2 only needs an overpotential of 237 mV to reach the current density of 10 mA cm-2 , with fast reaction kinetics and good stability.

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Vaccination is among the most effective ways to prevent infectious diseases. Subunit vaccines are safe but usually require multiple booster shots, which may lead to immunity loss and economic consume. In this study, a self-boosting vaccine is developed based on the pulsatile release of antigen from the core-shell microparticle after single-injection immunization. Self-healing technology applied to form an "antigen core" can avoid organic solvents from destroying the spatial structure of the antigen. The "antigen shell" is built-up by self-assemble of the antigen with the opposite charged polypeptide. Primary immunization occurs with the self-assembled film disintegration, and the booster comes with the microparticle degradation. The changing of antigen-specific antibodies after immunization with the core-shell microparticle vaccine is consistent with that caused by the two shots of immunization. The immune effect and safety evaluation results support the translational potential of this self-boosting core-shell microparticle vaccine.

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Inorganic nanoparticles with multiple functions have been attracting attention as multimodal nanoprobes in bioimaging, biomolecule detection, and medical diagnosis and treatment. A drawback of conventional metallic nanoparticle-based nanoprobes is the Ohmic losses that lead to fluorescence quenching of attached molecules and local heating under light irradiation. Here, metal-free nanoprobes capable of scattering/fluorescence dual-mode imaging are developed. The nanoprobes are composed of a silicon nanosphere core having efficient Mie scattering in the visible to near infrared range and a fluorophore doped silica shell. The dark-field scattering and photoluminescence images/spectra for nanoprobes made from different size silicon nanospheres and different kinds of fluorophores are studied by single particle spectroscopy. The fluorescence spectra are strongly modified by the Mie modes of a silicon nanosphere core. By comparing scattering and fluorescence spectra and calculated Purcell factors, the fluorescence enhancement factor is quantitatively discussed. In vitro scattering/fluorescence imaging studies on human cancer cells demonstrate that the developed nanoparticles work as scattering/fluorescence dual-mode imaging nanoprobes.

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BACKGROUND: In the present study, resveratrol was used to prepare complexes of cerium and nanoceria, also coated with gold (CeO2@Au core-shells) to improve the surface interactions in physiological conditions. METHODS: The CeO2@Au core-shells were characterized using powder X-ray diffraction (PXRD), Fourier transforms infrared spectroscopy (FTIR), transmission electron microscope (TEM) analysis, dynamic light scattering (DLS) and ζ potential. RESULTS: The experiment was led to the successful synthesis of nanosized CeO2@Au core-shells, although agglomeration of particles caused the distribution of the larger particles. The TEM analysis demonstrated the particles sizes ranged from 20 nm to 170 nm. Moreover, the PXRD analysis showed that both nanoceria and gold with the same crystal systems and space groups. To investigate the anticancer activity of the CeO2@Au core-shells, the cytotoxicity of the nanoparticles was investigated against liver cancerous cell lines (HepG2). CONCLUSIONS: The results indicated biosynthesized NCs have significant cellular toxicity properties against HepG2 and could be utilized in hepatocarcinoma therapy. Further in vivo investigations is proposed to be designed to assess anti-cancer and safety effects of fabricated nanocomposites.

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Interfacial effects on single-layer graphene (SLG) or multilayer graphene (MLG) properties greatly affect device performance. Thus, the effect of the interface on the temperature coefficient of resistance (TCR) on SLG and MLG due to surface-deposited core-shell metallic nanoparticles (MNPs) and various substrates was experimentally investigated. Observed substrates included glass, SiO2, and Si3N4. We show that these modifications can be used to strongly influence SLG interface effects, thus increasing the TCR up to a 0.456% per K resistance change when in contact with the SiO2 substrate at the bottom surface and MNPs on the top surface. However, these surface interactions are muted in MLG due to the screening effect of nonsuperficial layers, only achieving a -0.0998% per K resistance change in contact with the bottom Si3N4 substrate and the top MNPs. We also demonstrate contrary thermal sensitivity responses between SLG and MLG after the addition of MNP to the surface.

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In the present study, lipase production from mutated strain of Fusarium incarnatum KU377454 was optimized through central composite design (CCD) based response surface methodology (RSM). The maximum lipase production (4.01 IU/mL) was obtained within 4 days of incubation using 0.1% CaCl2 concentration and 8% wheat bran concentration. Further, salting out technique was applied for partial purification of lipase. The partially purified lipase was immobilized using Au@Ag bimetallic nanoshell. The characterization of immobilized lipase was carried out by transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), Fourier transformed infrared (FTIR), energy dispersive X-ray (EDX), X-ray diffraction (XRD) and thermo gravimetric analysis (TGA). The immobilized lipase could retain its 95% of activity after 15 days of storage at 4 °C. Subsequently, Au@Ag immobilized lipase was used for the degradation of waste cooking oil (WCO), which showed higher WCO degradation (85%) compared to the free lipase mediated waste cooking oil degradation (71%). The immobilized lipase could be reused for five times without any loss of its activity.

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Escherichia coli cells support the nucleation and growth of ruthenium and ruthenium-palladium nanoparticles (Bio-Ru and Bio-Pd/Ru NPs). We report a method for the synthesis of these monometallic and bimetallic NPs and their application in the catalytic upgrading of 5-hydroxymethyl furfural (5-HMF) to 2,5 dimethylfuran (DMF). Examination using high resolution transmission electron microscopy with energy dispersive X-ray microanalysis (EDX) and high angle annular dark field (HAADF) showed Ru NPs located mainly at the cell surface using Ru(III) alone but small intracellular Ru-NPs (size ∼1-2 nm) were visible only in cells that had been pre-"seeded" with Pd(0) (5 wt%) and loaded with equimolar Ru. Pd(0) NPs were distributed between the cytoplasm and cell surface. Cells bearing 5% Pd/5% Ru showed some co-localization of Pd and Ru but chance associations were not ruled out. Cells loaded to 5 wt% Pd/20 wt% Ru showed evidence of core-shell structures (Ru core, Pd shell). Examination of this cell surface material using X-ray photoelectron spectroscopy (XPS) showed Pd(0) and Pd(II) and Ru(IV) and Ru(III), with confirmation by analysis of bulk material using X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) analyses. Both Bio-Ru NPs and Bio-Pd/Ru NPs were active in the conversion of 5-HMF into 2,5-DMF but commercial Ru on carbon catalyst outperformed 5 wt% bio-Ru by fourfold. While 5 wt% Pd/20 wt% Ru achieved 20% yield of DMF the performance of the 5 wt% Pd/5 wt% Ru bio-catalyst was higher and comparable to the commercial 5 wt% Ru/C catalyst in a test reaction using commercial 5-HMF (>50% selectivity). 5-HMF was prepared by thermochemical hydrolysis of starch and cellulose with solvent extraction of 5-HMF into methyltetrahydrofuran (MTHF). Here, with MTHF as the reaction solvent the commercial Ru/C catalyst had little activity (100% conversion, negligible selectivity to DMF) whereas the 5 wt% Pd/5 wt% Ru bio-bimetallic gave 100% conversion and 14% selectivity to DMF from material extracted from hydrolyzates. The results indicate a potential green method for realizing increased energy potential from biomass wastes as well as showing a bio-based pathway to manufacturing a scarcely described bimetallic material.

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In this paper, we study magnetic and structural properties of silver and gold-coated iron nanoparticle as novel drug delivery systems for the two commercially famous cancer treatment drugs, using the density functional theory (DFT) computations. Our calculations show that silver and gold-coated iron nanoparticle have magnetization and the magnetic moment of the Fe atom in the Fe@(Ag/Au)n core-shells saturated to a value of about 3 µB. Thus the Fe@(Ag/Au)n core-shells are very promising to be functionalized for targeted drug delivery. Drug adsorption on the Gold coated iron show higher adsorption energy than Fe@Ag12 core-shell, Also, Mercaptopurine molecules showed higher adsorption energy than the Cisplatin. The Fe@Ag12 core-shells can deliver the drug into the cells while their properties are not significantly changed in the delivering process. Simulation results also have shown that in the low pH of tissue of a malignant tumor, the drug can be separated from the carrier which indicating the potential delivery vehicle of iron core-shells. Results of the calculations for core-shell structure of iron nanoparticle are very promising in biomedical applications and will contribute to the discovery of its novel applications in nanomedicine.

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All-inorganic semiconductor perovskite quantum dots (QDs) with outstanding optoelectronic properties have already been extensively investigated and implemented in various applications. However, great challenges exist for the fabrication of nanodevices including toxicity, fast anion-exchange reactions, and unsatisfactory stability. Here, the ultrathin, core-shell structured SiO2 coated Mn2+ doped CsPbX3 (X = Br, Cl) QDs are prepared via one facile reverse microemulsion method at room temperature. By incorporation of a multibranched capping ligand of trioctylphosphine oxide, it is found that the breakage of the CsPbMnX3 core QDs contributed from the hydrolysis of silane could be effectively blocked. The thickness of silica shell can be well-controlled within 2 nm, which gives the CsPbMnX3 @SiO2 QDs a high quantum yield of 50.5% and improves thermostability and water resistance. Moreover, the mixture of CsPbBr3 QDs with green emission and CsPbMnX3 @SiO2 QDs with yellow emission presents no ion exchange effect and provides white light emission. As a result, a white light-emitting diode (LED) is successfully prepared by the combination of a blue on-chip LED device and the above perovskite mixture. The as-prepared white LED displays a high luminous efficiency of 68.4 lm W-1 and a high color-rendering index of Ra = 91, demonstrating their broad future applications in solid-state lighting fields.

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Core-shells metallic nanoparticles have the advantage of possessing two plasmon resonances, one in the visible and one in the infrared part of the spectrum. This special property is used in this work to enhance the efficiency of thin film solar cells by improving the optical absorption at both wavelength ranges simultaneously by using a neural network. Although many thin-film solar cell compositions can benefit from such a design, in this work, different silver core-shell configurations were explored inside a Halide Perovskite (CH3NH3PbI3) thin film. Because the number of potential configurations is infinite, only a limited number of finite difference time domain (FDTD) simulations were performed. A neural network was then trained with the simulation results to find the core-shells configurations with optimal optical absorption across different wavelength ranges. This demonstrates that core-shells nanoparticles can make an important contribution to improving solar cell performance and that neural networks can be used to find optimal results in such nanophotonic systems.

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Oil-in-water emulsions represent a promising carrier for in vivo imaging because of the possibility to convey poorly water-soluble species. To promote accumulation at the tumor site and prolong circulation time, reduction of carrier size and surface PEGylation plays a fundamental role. In this work a novel, simple method to design an oil-core/PEG-shell nanocarrier is reported. A PEG-shell is grown around a monodisperse oil-in-water nanoemulsion with a one-pot method, using the radical polymerization of poly(ethylene glycol)diacrylate. PEG polymerization is triggered by UV, obtaining a PEG-shell with tunable thickness. This core-shell nanosystem combines the eluding feature of the PEG with the ability to confine high payloads of lipophilic species. Indeed, the core is successfully loaded with a lipophilic contrast agent, namely super paramagnetic iron oxide nanocubes. Interestingly, it is demonstrated an in vitro and an in vivo MRI response of the nanocapsules. Additionally, when the nanosystem loaded with nanocubes is mixed with a fluorescent contrast agent, indo-cyanine green, a relevant in vitro photoacoustic effect is observed. Moreover, viability and cellular uptake studies show no significant cell cytotoxicity. These results, together with the choice of low cost materials and the scale up production, make this nanocarrier a potential platform for in vivo imaging.

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The main advantage of a theoretical approach is essential knowledge of the mechanisms that allow us to comprehend the experimental conditions that we have to fulfill to be able to get the desired results. Based on our research in ultrathin crystal structures performed so far, superlattices, Q-wires and Q-dots, we will consider the materials that can act as carriers for medicines and tagged substances. For this purpose we established a shell-model of ultrathin crystals and investigated their fundamental characteristics. This could be considered as a form of nano-engineering. In this paper we will analyze application of nanomaterials in biomedicine, that is to say we will present the recent accomplishments in basic and clinical nanomedicine. Achieving full potential of nanomedicine may be years or even decades away, however, potential advances in drug delivery, diagnosis, and development of nanotechnology-related drugs start to change the landscape of medicine. Site-specific targeted drug delivery (made possible by the availability of unique delivery platforms, such as dendrimers, nanoparticles and nanoliposomes) and personalized medicines (result of the advance in pharmacogenetics) are just a few concepts on the horizon of research. In this paper, especially, we have analyzed the changes in basic physical properties of spherical-shaped nanoparticles that can be made in several (nano)layers and have, at the same time, multiple applications in medicine. This paper presents a review of our current achievement in the field of theoretical physics of ultrathin films and possible ways to materialize the same in the field of nanopharmacy.

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Double layered one-by-one imprinted hollow core-shells@ pencil graphite electrode was fabricated for sequential sensing of anti-HIV drugs. For this, two eccentric layers were developed on the surface of vinylated silica nanospheres to obtain double layered one-by-one imprinted solid core-shells. This yielded hollow core-shells on treatment with hydrofluoric acid. The modified hollow core-shells (single layered dual imprinted) evolved competitive diffusion of probe/analyte molecules. However, the corresponding double layered one-by-one imprinted hollow core-shells (outer layer imprinted with Zidovudine, and inner layer with Lamivudine) were found relatively better owing to their bilateral diffusions into molecular cavities, without any competition. The entire work is based on differential pulse anodic stripping voltammetry at double layered one-by-one imprinted hollow core-shells. This resulted in indirect detection of electro inactive targets with limits of detection as low as 0.91 and 0.12 (aqueous sample), 0.94 and 0.13 (blood serum), and 0.99 and 0.20 ng mL-1 (pharmaceutics) for lamivudine and zidovudine, respectively in anti-HIV drug combination.

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An array consisting of homogeneous NiCo2S4 hollow core-shell nanoneedles was fabricated and is shown to enable sensitive electrochemical determination of dopamine (DA). The array was grown directly on a nickel foam (NF) substrate by a two-step hydrothermal process. The hierarchical nanoarray consists of a homogeneous NiCo2S4 nanoneedle core and a NiCo2S4 nanosheet shell. A 3-dimensional micro/nano structure is formed due to the presence of the micropores of the NF. The electrode was characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Compared to a plain NF electrode, the NiCo2S4-modified NF electrode displays higher electrocatalytic activity for the oxidation of DA by differential pulse voltammetry (DPV). The sensor, best operated at a typical working voltage of 134 mV (vs. saturated calomel electrode), has a linear response in the 0.5-100 µM DA concentration range and a 0.2 µM detection limit (at S/N = 3). The electrode is selective over ascorbic acid and uric acid. Graphical abstract Schematic presentation of an electrochemical sensor for selective determination of dopamine based on the use of a homogeneous NiCo2S4 hollow core-shell nanoneedle array on nickel foam.