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Nanomaterials, Volume 5, Issue 4 (December 2015), Pages 1556-2390

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Open AccessArticle A Paper-Based Sandwich Format Hybridization Assay for Unlabeled Nucleic Acid Detection Using Upconversion Nanoparticles as Energy Donors in Luminescence Resonance Energy Transfer
Nanomaterials 2015, 5(4), 1556-1570; doi:10.3390/nano5041556
Received: 24 July 2015 / Revised: 12 September 2015 / Accepted: 22 September 2015 / Published: 24 September 2015
Cited by 4 | PDF Full-text (3918 KB) | HTML Full-text | XML Full-text
Abstract
Bioassays based on cellulose paper substrates are gaining increasing popularity for the development of field portable and low-cost diagnostic applications. Herein, we report a paper-based nucleic acid hybridization assay using immobilized upconversion nanoparticles (UCNPs) as donors in luminescence resonance energy transfer (LRET). UCNPs
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Bioassays based on cellulose paper substrates are gaining increasing popularity for the development of field portable and low-cost diagnostic applications. Herein, we report a paper-based nucleic acid hybridization assay using immobilized upconversion nanoparticles (UCNPs) as donors in luminescence resonance energy transfer (LRET). UCNPs with intense green emission served as donors with Cy3 dye as the acceptor. The avidin functionalized UCNPs were immobilized on cellulose paper and subsequently bioconjugated to biotinylated oligonucleotide probes. Introduction of unlabeled oligonucleotide targets resulted in a formation of probe-target duplexes. A subsequent hybridization of Cy3 labeled reporter with the remaining single stranded portion of target brought the Cy3 dye in close proximity to the UCNPs to trigger a LRET-sensitized emission from the acceptor dye. The hybridization assays provided a limit of detection (LOD) of 146.0 fmol and exhibited selectivity for one base pair mismatch discrimination. The assay was functional even in undiluted serum samples. This work embodies important progress in developing DNA hybridization assays on paper. Detection of unlabeled targets is achieved using UCNPs as LRET donors, with minimization of background signal from paper substrates owing to the implementation of low energy near-infrared (NIR) excitation. Full article
(This article belongs to the Special Issue Nanomaterials for Biosensing Applications)
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Open AccessArticle Preparation of GST Inhibitor Nanoparticle Drug Delivery System and Its Reversal Effect on the Multidrug Resistance in Oral Carcinoma
Nanomaterials 2015, 5(4), 1571-1587; doi:10.3390/nano5041571
Received: 25 August 2015 / Revised: 23 September 2015 / Accepted: 24 September 2015 / Published: 29 September 2015
Cited by 1 | PDF Full-text (1928 KB) | HTML Full-text | XML Full-text
Abstract
During the chemotherapy of cancer, drug resistance is the first issue that chemotherapeutic drugs cannot be effectively used for the treatment of cancers repeatedly for a long term, and the main reason for this is that tumor cell detoxification is mediated by GSH
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During the chemotherapy of cancer, drug resistance is the first issue that chemotherapeutic drugs cannot be effectively used for the treatment of cancers repeatedly for a long term, and the main reason for this is that tumor cell detoxification is mediated by GSH (glutathione) catalyzed by GST (glutathione-S-transferase). In this study, a GST inhibitor, ethacrynic acid (ECA), was designed to be coupled with methoxy poly(ethylene glycol)-poly(lactide) (MPEG–PLA) by disulfide bonds to prepare methoxy poly(ethylene glycol)-poly(lactide)-disulphide bond-mthacrynic acid (MPEG–PLA–SS–ECA) as a carrier material of the nanoparticles. Nanoparticles of pingyangmycin (PYM) and carboplatin (CBP) were prepared, respectively, and their physicochemical properties were investigated. The ECA at the disulfide could be released in the presence of GSH, the pingyangmycin, carboplatin and ECA were all uniformly released, and the nanoparticles could release all the drugs completely within 10 days. The half maximal inhibitory concentration (IC50) of the prepared MPEG–PLA–SS–ECA/CBP and MPEG–PLA–SS–ECA/PYM nanoparticles in drug-resistant oral squamous cell carcinoma cell lines SCC15/CBP and SCC15/PYM cells was 12.68 μg·mL1 and 12.76 μg·mL1, respectively; the resistant factor RF of them in the drug-resistant cells were 1.51 and 1.24, respectively, indicating that MPEG–PLA–SS–ECA nanoparticles can reverse the drug resistance of these two drug-resistant cells. Full article
(This article belongs to the Special Issue Nanomaterials for Cancer Therapies)
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Open AccessArticle Iron Oxide Nanoparticles Coated with a Phosphorothioate Oligonucleotide and a Cationic Peptide: Exploring Four Different Ways of Surface Functionalization
Nanomaterials 2015, 5(4), 1588-1609; doi:10.3390/nano5041588
Received: 18 August 2015 / Revised: 22 September 2015 / Accepted: 23 September 2015 / Published: 29 September 2015
Cited by 3 | PDF Full-text (996 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The superparamagnetic iron oxide nanoparticles (SPIONs) have great potential in therapeutic and diagnostic applications. Due to their superparamagnetic behavior, they are used clinically as a Magnetic Resonance Imaging (MRI) contrast agent. Iron oxide nanoparticles are also recognized todays as smart drug-delivery systems. However,
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The superparamagnetic iron oxide nanoparticles (SPIONs) have great potential in therapeutic and diagnostic applications. Due to their superparamagnetic behavior, they are used clinically as a Magnetic Resonance Imaging (MRI) contrast agent. Iron oxide nanoparticles are also recognized todays as smart drug-delivery systems. However, to increase their specificity, it is essential to functionalize them with a molecule that effectively targets a specific area of the body. Among the molecules that can fulfill this role, peptides are excellent candidates. Oligonucleotides are recognized as potential drugs for various diseases but suffer from poor uptake and intracellular degradation. In this work, we explore four different strategies, based on the electrostatic interactions between the different partners, to functionalize the surface of SPIONs with a phosphorothioate oligonucleotide (ODN) and a cationic peptide labeled with a fluorophore. The internalization of the nanoparticles has been evaluated in vitro on RAW 264.7 cells. Among these strategies, the “«one-step assembly»”, i.e., the direct complexation of oligonucleotides and peptides on iron oxide nanoparticles, provides the best way of coating for the internalization of the nanocomplexes. Full article
(This article belongs to the Special Issue Nanoparticles in Theranostics)
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Open AccessCommunication Controllable Synthesis of Copper Oxide/Carbon Core/Shell Nanowire Arrays and Their Application for Electrochemical Energy Storage
Nanomaterials 2015, 5(4), 1610-1619; doi:10.3390/nano5041610
Received: 10 September 2015 / Revised: 6 October 2015 / Accepted: 8 October 2015 / Published: 9 October 2015
Cited by 4 | PDF Full-text (2610 KB) | HTML Full-text | XML Full-text
Abstract
Rational design/fabrication of integrated porous metal oxide arrays is critical for the construction of advanced electrochemical devices. Herein, we report self-supported CuO/C core/shell nanowire arrays prepared by the combination of electro-deposition and chemical vapor deposition methods. CuO/C nanowires with diameters of ~400 nm
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Rational design/fabrication of integrated porous metal oxide arrays is critical for the construction of advanced electrochemical devices. Herein, we report self-supported CuO/C core/shell nanowire arrays prepared by the combination of electro-deposition and chemical vapor deposition methods. CuO/C nanowires with diameters of ~400 nm grow quasi-vertically to the substrates forming three-dimensional arrays architecture. A thin carbon shell is uniformly coated on the CuO nanowire cores. As an anode of lithium ion batteries, the resultant CuO/C nanowire arrays are demonstrated to have high specific capacity (672 mAh·g−1 at 0.2 C) and good cycle stability (425 mAh·g−1 at 1 C up to 150 cycles). The core/shell arrays structure plays positive roles in the enhancement of Li ion storage due to fast ion/electron transfer path, good strain accommodation and sufficient contact between electrolyte and active materials. Full article
(This article belongs to the Special Issue Nanostructured Materials for Li-Ion Batteries and Beyond)
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Open AccessArticle High Rate Performance Nanocomposite Electrode of Mesoporous Manganese Dioxide/Silver Nanowires in KI Electrolytes
Nanomaterials 2015, 5(4), 1638-1653; doi:10.3390/nano5041638
Received: 7 August 2015 / Revised: 9 September 2015 / Accepted: 28 September 2015 / Published: 13 October 2015
Cited by 6 | PDF Full-text (1601 KB) | HTML Full-text | XML Full-text
Abstract
In recent years, manganese dioxide has become a research hotspot as an electrode material because of its low price. However, it has also become an obstacle to industrialization due to its low ratio of capacitance and the low rate performance which is caused
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In recent years, manganese dioxide has become a research hotspot as an electrode material because of its low price. However, it has also become an obstacle to industrialization due to its low ratio of capacitance and the low rate performance which is caused by the poor electrical conductivity. In this study, a KI solution with electrochemical activity was innovatively applied to the electrolyte, and we systematically investigated the rate performance of the mesoporous manganese dioxide and the composite electrode with silver nanowires in supercapacitors. The results showed that when mesoporous manganese dioxide and mesoporous manganese dioxide/silver nanowires composite were used as electrodes, the strength of the current was amplified five times (from 0.1 to 0.5 A/g), the remaining rates of specific capacitance were 95% (from 205.5 down to 197.1 F/g) and 92% (from 208.1 down to 191.7 F/g) in the KI electrolyte, and the rate performance was much higher than which in an Na2SO4 electrolyte with a remaining rate of 25% (from 200.3 down to 49.1 F/g) and 60% (from 187.2 down to 113.1 F/g). The morphology and detail structure were investigated by Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectrometry and Nitrogen adsorption-desorption isotherms. The electrochemical performance was assessed by cyclic voltammograms, galvanostatic charge/discharge and electrochemical impedance spectroscopy. Full article
(This article belongs to the Special Issue Frontiers in Mesoporous Nanomaterials)
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Open AccessArticle Computational Evaluation of Amorphous Carbon Coating for Durable Silicon Anodes for Lithium-Ion Batteries
Nanomaterials 2015, 5(4), 1654-1666; doi:10.3390/nano5041654
Received: 3 August 2015 / Revised: 22 September 2015 / Accepted: 3 October 2015 / Published: 13 October 2015
Cited by 1 | PDF Full-text (1728 KB) | HTML Full-text | XML Full-text
Abstract
We investigate the structural, mechanical, and electronic properties of graphite-like amorphous carbon coating on bulky silicon to examine whether it can improve the durability of the silicon anodes of lithium-ion batteries using molecular dynamics simulations and ab-initio electronic structure calculations. Structural models of
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We investigate the structural, mechanical, and electronic properties of graphite-like amorphous carbon coating on bulky silicon to examine whether it can improve the durability of the silicon anodes of lithium-ion batteries using molecular dynamics simulations and ab-initio electronic structure calculations. Structural models of carbon coating are constructed using molecular dynamics simulations of atomic carbon deposition with low incident energies (1–16 eV). As the incident energy decreases, the ratio of sp2 carbons increases, that of sp3 decreases, and the carbon films become more porous. The films prepared with very low incident energy contain lithium-ion conducting channels. Also, those films are electrically conductive to supplement the poor conductivity of silicon and can restore their structure after large deformation to accommodate the volume change during the operations. As a result of this study, we suggest that graphite-like porous carbon coating on silicon will extend the lifetime of the silicon anodes of lithium-ion batteries. Full article
(This article belongs to the Special Issue Nanostructured Materials for Li-Ion Batteries and Beyond)
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Open AccessArticle Voltammetric Determination of Ferulic Acid Using Polypyrrole-Multiwalled Carbon Nanotubes Modified Electrode with Sample Application
Nanomaterials 2015, 5(4), 1704-1715; doi:10.3390/nano5041704
Received: 26 August 2015 / Accepted: 12 October 2015 / Published: 16 October 2015
Cited by 1 | PDF Full-text (782 KB) | HTML Full-text | XML Full-text
Abstract
A polypyrrole-multiwalled carbon nanotubes modified glassy carbon electrode-based sensor was devised for determination of ferulic acid (FA). The fabricated sensor was prepared electrochemically using cyclic voltammetry (CV) and characterized using CV and scanning electron microscope (SEM). The electrode shows an excellent electrochemical catalytic
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A polypyrrole-multiwalled carbon nanotubes modified glassy carbon electrode-based sensor was devised for determination of ferulic acid (FA). The fabricated sensor was prepared electrochemically using cyclic voltammetry (CV) and characterized using CV and scanning electron microscope (SEM). The electrode shows an excellent electrochemical catalytic activity towards FA oxidation. Under optimal conditions, the anodic peak current correlates linearly to the FA concentration throughout the range of 3.32 × 10−6 to 2.59 × 10−5 M with a detection limit of 1.17 × 10−6 M (S/N = 3). The prepared sensor is highly selective towards ferulic acid without the interference of ascorbic acid. The sensor applicability was tested for total content determination of FA in a commercial popcorn sample and showed a robust functionality. Full article
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Open AccessArticle Dendrimer-Functionalized Laponite Nanodisks as a Platform for Anticancer Drug Delivery
Nanomaterials 2015, 5(4), 1716-1731; doi:10.3390/nano5041716
Received: 18 September 2015 / Revised: 7 October 2015 / Accepted: 13 October 2015 / Published: 20 October 2015
Cited by 6 | PDF Full-text (2829 KB) | HTML Full-text | XML Full-text
Abstract
In this study, we synthesized dendrimer-functionalized laponite (LAP) nanodisks for loading and delivery of anticancer drug doxorubicin (DOX). Firstly, LAP was modified with silane coupling agents and succinic anhydride to render abundant carboxyl groups on the surface of LAP. Then, poly(amidoamine) (PAMAM) dendrimer
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In this study, we synthesized dendrimer-functionalized laponite (LAP) nanodisks for loading and delivery of anticancer drug doxorubicin (DOX). Firstly, LAP was modified with silane coupling agents and succinic anhydride to render abundant carboxyl groups on the surface of LAP. Then, poly(amidoamine) (PAMAM) dendrimer of generation 2 (G2) were conjugated to form LM-G2 nanodisks. Anticancer drug DOX was then loaded on the LM-G2 with an impressively high drug loading efficiency of 98.4% and could be released in a pH-sensitive and sustained manner. Moreover, cell viability assay results indicate that LM-G2/DOX complexes could more effectively inhibit the proliferation of KB cells (a human epithelial carcinoma cell line) than free DOX at the same drug concentration. Flow cytometry analysis and confocal laser scanning microscope demonstrated that LM-G2/DOX could be uptaken by KB cells more effectively than free DOX. Considering the exceptional high drug loading efficiency and the abundant dendrimer amine groups on the surface that can be further modified, the developed LM-G2 nanodisks may hold a great promise to be used as a novel platform for anticancer drug delivery. Full article
(This article belongs to the Special Issue Nanoparticles Assisted Drug Delivery)
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Open AccessArticle Direct Growth of Bismuth Film as Anode for Aqueous Rechargeable Batteries in LiOH, NaOH and KOH Electrolytes
Nanomaterials 2015, 5(4), 1756-1765; doi:10.3390/nano5041756
Received: 19 September 2015 / Revised: 3 October 2015 / Accepted: 16 October 2015 / Published: 22 October 2015
Cited by 5 | PDF Full-text (1811 KB) | HTML Full-text | XML Full-text
Abstract
As promising candidates for next-generation energy storage devices, aqueous rechargeable batteries are safer and cheaper than organic Li ion batteries. But due to the narrow voltage window of aqueous electrolytes, proper anode materials with low redox potential and high capacity are quite rare.
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As promising candidates for next-generation energy storage devices, aqueous rechargeable batteries are safer and cheaper than organic Li ion batteries. But due to the narrow voltage window of aqueous electrolytes, proper anode materials with low redox potential and high capacity are quite rare. In this work, bismuth electrode film was directly grown by a facile hydrothermal route and tested in LiOH, NaOH and KOH electrolytes. With low redox potential (reduction/oxidation potentials at ca. −0.85/−0.52 V vs. SCE, respectively) and high specific capacity (170 mAh·g−1 at current density of 0.5 A·g−1 in KOH electrolyte), Bi was demonstrated as a suitable anode material for aqueous batteries. Furthermore, by electrochemical impedance spectroscopy (EIS) analysis, we found that with smaller Rs and faster ion diffusion coefficient, Bi electrode film in KOH electrolyte exhibited better electrochemical performance than in LiOH and NaOH electrolytes. Full article
(This article belongs to the Special Issue Nanostructured Materials for Li-Ion Batteries and Beyond)
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Open AccessArticle Control of Partial Coalescence of Self-Assembled Metal Nano-Particles across Lyotropic Liquid Crystals Templates towards Long Range Meso-Porous Metal Frameworks Design
Nanomaterials 2015, 5(4), 1766-1781; doi:10.3390/nano5041766
Received: 30 September 2015 / Revised: 19 October 2015 / Accepted: 22 October 2015 / Published: 26 October 2015
Cited by 1 | PDF Full-text (2401 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The formation of purely metallic meso-porous metal thin films by partial interface coalescence of self-assembled metal nano-particles across aqueous solutions of Pluronics triblock lyotropic liquid crystals is demonstrated for the first time. Small angle X-ray scattering was used to study the influence of
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The formation of purely metallic meso-porous metal thin films by partial interface coalescence of self-assembled metal nano-particles across aqueous solutions of Pluronics triblock lyotropic liquid crystals is demonstrated for the first time. Small angle X-ray scattering was used to study the influence of the thin film composition and processing conditions on the ordered structures. The structural characteristics of the meso-structures formed demonstrated to primarily rely on the lyotropic liquid crystal properties while the nature of the metal nano-particles used as well as the their diameters were found to affect the ordered structure formation. The impact of the annealing temperature on the nano-particle coalescence and efficiency at removing the templating lyotropic liquid crystals was also analysed. It is demonstrated that the lyotropic liquid crystal is rendered slightly less thermally stable, upon mixing with metal nano-particles and that low annealing temperatures are sufficient to form purely metallic frameworks with average pore size distributions smaller than 500 nm and porosity around 45% with potential application in sensing, catalysis, nanoscale heat exchange, and molecular separation. Full article
(This article belongs to the Special Issue Frontiers in Mesoporous Nanomaterials)
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Open AccessArticle Organic Phase Change Nanoparticles for in-Product Labeling of Agrochemicals
Nanomaterials 2015, 5(4), 1810-1819; doi:10.3390/nano5041810
Received: 15 September 2015 / Revised: 13 October 2015 / Accepted: 26 October 2015 / Published: 28 October 2015
Cited by 2 | PDF Full-text (1087 KB) | HTML Full-text | XML Full-text
Abstract
There is an urgent need to develop in-product covert barcodes for anti-counterfeiting of agrochemicals. This paper reports a new organic nanoparticle-based in-product barcode system, in which a panel of organic phase change nanoparticles is added as a barcode into in a variety of
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There is an urgent need to develop in-product covert barcodes for anti-counterfeiting of agrochemicals. This paper reports a new organic nanoparticle-based in-product barcode system, in which a panel of organic phase change nanoparticles is added as a barcode into in a variety of chemicals (herein agrochemicals). The barcode is readout by detecting melting peaks of organic nanoparticles using differential scanning calorimetry. This method has high labeling capacity due to small sizes of nanoparticles, sharp melting peaks, and large scan range of thermal analysis. The in-product barcode can be effectively used to protect agrochemical products from being counterfeited due to its large coding capacity, technical readiness, covertness, and robustness. Full article
(This article belongs to the Special Issue Engineered Nanomaterials in the Environment)
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Open AccessArticle Chalcopyrite Nanoparticles as a Sustainable Thermoelectric Material
Nanomaterials 2015, 5(4), 1820-1830; doi:10.3390/nano5041820
Received: 17 August 2015 / Revised: 23 October 2015 / Accepted: 26 October 2015 / Published: 29 October 2015
PDF Full-text (652 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
In this report, copper iron sulfide nanoparticles with various composition were synthesized by a thermolysis based wet chemical method. These inherently sustainable nanoparticles were then fully characterized in terms of composition, structure, and morphology, as well as for suitability as a thermoelectric material.
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In this report, copper iron sulfide nanoparticles with various composition were synthesized by a thermolysis based wet chemical method. These inherently sustainable nanoparticles were then fully characterized in terms of composition, structure, and morphology, as well as for suitability as a thermoelectric material. The merits of the material preparation include a straightforward bulk material formation where particles do not require any specialized treatment, such as spark plasma sintering or thermal heating. The Seebeck coefficient of the materials reveals P-type conductivity with a maximum value of 203 µV/K. The results give insight into how to design and create a new class of sustainable nanoparticle material for thermoelectric applications. Full article
(This article belongs to the Special Issue Nanomaterials for Cancer Therapies)
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Open AccessArticle Effects of Annealing Temperature on Properties of Ti-Ga–Doped ZnO Films Deposited on Flexible Substrates
Nanomaterials 2015, 5(4), 1831-1839; doi:10.3390/nano5041831
Received: 8 October 2015 / Revised: 20 October 2015 / Accepted: 29 October 2015 / Published: 3 November 2015
Cited by 6 | PDF Full-text (2348 KB) | HTML Full-text | XML Full-text
Abstract
An investigation is performed into the optical, electrical, and microstructural properties of Ti-Ga–doped ZnO films deposited on polyimide (PI) flexible substrates and then annealed at temperatures of 300 °C, 400 °C, and 450 °C, respectively. The X-ray diffraction (XRD) analysis results show that
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An investigation is performed into the optical, electrical, and microstructural properties of Ti-Ga–doped ZnO films deposited on polyimide (PI) flexible substrates and then annealed at temperatures of 300 °C, 400 °C, and 450 °C, respectively. The X-ray diffraction (XRD) analysis results show that all of the films have a strong (002) Ga doped ZnO (GZO) preferential orientation. As the annealing temperature is increased to 400 °C, the optical transmittance increases and the electrical resistivity decreases. However, as the temperature is further increased to 450 °C, the transmittance reduces and the resistivity increases due to a carbonization of the PI substrate. Finally, the crystallinity of the ZnO film improves with an increasing annealing temperature only up to 400 °C and is accompanied by a smaller crystallite size and a lower surface roughness. Full article
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Open AccessArticle Structural Stability of Diffusion Barriers in Cu/Ru/MgO/Ta/Si
Nanomaterials 2015, 5(4), 1840-1852; doi:10.3390/nano5041840
Received: 30 August 2015 / Revised: 18 October 2015 / Accepted: 26 October 2015 / Published: 3 November 2015
Cited by 2 | PDF Full-text (5799 KB) | HTML Full-text | XML Full-text
Abstract
Various structures of Cu (50 nm)/Ru (2 nm)/MgO (0.5–3 nm)/Ta (2 nm)/Si were prepared by sputtering and electroplating techniques, in which the ultra-thin trilayer of Ru (2 nm)/MgO (0.5–3 nm)/Ta (2 nm) is used as the diffusion barrier against the interdiffusion between Cu
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Various structures of Cu (50 nm)/Ru (2 nm)/MgO (0.5–3 nm)/Ta (2 nm)/Si were prepared by sputtering and electroplating techniques, in which the ultra-thin trilayer of Ru (2 nm)/MgO (0.5–3 nm)/Ta (2 nm) is used as the diffusion barrier against the interdiffusion between Cu film and Si substrate. The various structures of Cu/Ru/MgO/Ta/Si were characterized by four-point probes for their sheet resistances, by X-ray diffractometers for their crystal structures, by scanning electron microscopes for their surface morphologies, and by transmission electron microscopes for their cross-section and high resolution views. The results showed that the ultra-thin tri-layer of Ru (2 nm)/MgO (0.5–3 nm)/Ta (2 nm) is an effective diffusion barrier against the interdiffusion between Cu film and Si substrate. The MgO, and Ta layers as deposited are amorphous. The mechanism for the failure of the diffusion barrier is that the Ru layer first became discontinuous at a high temperature and the Ta layer sequentially become discontinuous at a higher temperature, the Cu atoms then diffuse through the MgO layer and to the substrate at the discontinuities, and the Cu3Si phases finally form. The maximum temperature at which the structures of Cu (50 nm)/Ru (2 nm)/MgO (0.5–3 nm)/Ta (2 nm)/Si are annealed and still have low sheet resistance is from 550 to 750 °C for the annealing time of 5 min and from 500 to 700 °C for the annealing time of 30 min. Full article
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Open AccessArticle T1-MRI Fluorescent Iron Oxide Nanoparticles by Microwave Assisted Synthesis
Nanomaterials 2015, 5(4), 1880-1890; doi:10.3390/nano5041880
Received: 7 October 2015 / Revised: 26 October 2015 / Accepted: 28 October 2015 / Published: 4 November 2015
Cited by 4 | PDF Full-text (658 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Iron oxide nanoparticles have long been studied as a T2 contrast agent in MRI due to their superparamagnetic behavior. T1-based positive contrast, being much more favorable for clinical application due to brighter and more accurate signaling is, however, still limited
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Iron oxide nanoparticles have long been studied as a T2 contrast agent in MRI due to their superparamagnetic behavior. T1-based positive contrast, being much more favorable for clinical application due to brighter and more accurate signaling is, however, still limited to gadolinium- or manganese-based imaging tools. Though being the only available commercial positive-contrast agents, they lack an efficient argument when it comes to biological toxicity and their circulatory half-life in blood. The need arises to design a biocompatible contrast agent with a scope for easy surface functionalization for long circulation in blood and/or targeted imaging. We hereby propose an extremely fast microwave synthesis for fluorescein-labeled extremely-small iron oxide nanoparticles (fdIONP), in a single step, as a viable tool for cell labeling and T1-MRI. We demonstrate the capabilities of such an approach through high-quality magnetic resonance angiographic images of mice. Full article
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Open AccessArticle Nanoporous Carbon Nanofibers Decorated with Platinum Nanoparticles for Non-Enzymatic Electrochemical Sensing of H2O2
Nanomaterials 2015, 5(4), 1891-1905; doi:10.3390/nano5041891
Received: 29 August 2015 / Revised: 25 October 2015 / Accepted: 30 October 2015 / Published: 6 November 2015
Cited by 11 | PDF Full-text (3384 KB) | HTML Full-text | XML Full-text
Abstract
We describe the preparation of nanoporous carbon nanofibers (CNFs) decorated with platinum nanoparticles (PtNPs) in this work by electrospining polyacrylonitrile (PAN) nanofibers and subsequent carbonization and binding of PtNPs. The fabricated nanoporous CNF-PtNP hybrids were further utilized to modify glass carbon electrodes and
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We describe the preparation of nanoporous carbon nanofibers (CNFs) decorated with platinum nanoparticles (PtNPs) in this work by electrospining polyacrylonitrile (PAN) nanofibers and subsequent carbonization and binding of PtNPs. The fabricated nanoporous CNF-PtNP hybrids were further utilized to modify glass carbon electrodes and used for the non-enzymatic amperometric biosensor for the highly sensitive detection of hydrogen peroxide (H2O2). The morphologies of the fabricated nanoporous CNF-PtNP hybrids were observed by scanning electron microscopy, transmission electron microscopy, and their structure was further investigated with Brunauer–Emmett–Teller (BET) surface area analysis, X-ray photoelectron spectroscopy, X-ray diffraction, and Raman spectrum. The cyclic voltammetry experiments indicate that CNF-PtNP modified electrodes have high electrocatalytic activity toward H2O2 and the chronoamperometry measurements illustrate that the fabricated biosensor has a high sensitivity for detecting H2O2. We anticipate that the strategies utilized in this work will not only guide the further design and fabrication of functional nanofiber-based biomaterials and nanodevices, but also extend the potential applications in energy storage, cytology, and tissue engineering. Full article
(This article belongs to the Special Issue Nanomaterials for Biosensing Applications)
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Open AccessArticle Cytotoxicity, Uptake Behaviors, and Oral Absorption of Food Grade Calcium Carbonate Nanomaterials
Nanomaterials 2015, 5(4), 1938-1954; doi:10.3390/nano5041938
Received: 15 October 2015 / Revised: 1 November 2015 / Accepted: 4 November 2015 / Published: 10 November 2015
Cited by 4 | PDF Full-text (751 KB) | HTML Full-text | XML Full-text
Abstract
Calcium is the most abundant mineral in human body and essential for the formation and maintenance of bones and teeth as well as diverse cellular functions. Calcium carbonate (CaCO3) is widely used as a dietary supplement; however, oral absorption efficiency of
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Calcium is the most abundant mineral in human body and essential for the formation and maintenance of bones and teeth as well as diverse cellular functions. Calcium carbonate (CaCO3) is widely used as a dietary supplement; however, oral absorption efficiency of CaCO3 is extremely low, which may be overcome by applying nano-sized materials. In this study, we evaluated the efficacy of food grade nano CaCO3 in comparison with that of bulk- or reagent grade nano CaCO3 in terms of cytotoxicity, cellular uptake, intestinal transport, and oral absorption. Cytotoxicity results demonstrated that nano-sized CaCO3 particles were slightly more toxic than bulk materials in terms of oxidative stress and membrane damage. Cellular uptake behaviors of CaCO3 nanoparticles were different from bulk CaCO3 or Ca2+ ions in human intestinal epithelial cells, showing efficient cellular internalization and elevated intracellular Ca2+ levels. Meanwhile, CaCO3 nanoparticles were efficiently transported by microfold (M) cells in vitro model of human intestinal follicle-associated epithelium, in a similar manner as Ca2+ ions did. Biokinetic study revealed that the biological fate of CaCO3 particles was different from Ca2+ ions; however, in vivo, its oral absorption was not significantly affected by particle size. These findings provide crucial information to understand and predict potential toxicity and oral absorption efficiency of food grade nanoparticles. Full article
(This article belongs to the Special Issue Nanoparticles Assisted Drug Delivery)
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Open AccessArticle Surface Properties and Photocatalytic Activities of the Colloidal ZnS:Mn Nanocrystals Prepared at Various pH Conditions
Nanomaterials 2015, 5(4), 1955-1970; doi:10.3390/nano5041955
Received: 29 September 2015 / Revised: 23 October 2015 / Accepted: 5 November 2015 / Published: 11 November 2015
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Abstract
Water-dispersible ZnS:Mn nanocrystals (NC) were synthesized by capping the surface with mercaptoacetic acid (MAA) molecules at three different pH conditions. The obtained ZnS:Mn-MAA NC products were physically and optically characterized by corresponding spectroscopic methods. The UV-Visible absorption spectra and PL emission spectra showed
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Water-dispersible ZnS:Mn nanocrystals (NC) were synthesized by capping the surface with mercaptoacetic acid (MAA) molecules at three different pH conditions. The obtained ZnS:Mn-MAA NC products were physically and optically characterized by corresponding spectroscopic methods. The UV-Visible absorption spectra and PL emission spectra showed broad peaks at 310 and 590 nm, respectively. The average particle sizes measured from the HR-TEM images were 5 nm, which were also supported by the Debye-Scherrer calculations using the X-ray diffraction (XRD) data. Moreover, the surface charges and the degrees of aggregation of the ZnS:Mn-MAA NCs were determined by electrophoretic and hydrodynamic light scattering methods, indicating formation of agglomerates in water with various sizes (50–440 nm) and different surface charge values accordingly the preparation conditions of the NCs (−7.59 to −24.98 mV). Finally, the relative photocatalytic activities of the ZnS:Mn-MAA NCs were evaluated by measuring the degradation rate of methylene blue (MB) molecule in a pseudo first-order reaction condition under the UV-visible light irradiation. As a result, the ZnS:Mn-MAA NC prepared at the pH 7 showed the best photo-degradation efficiency of the MB molecule with the first-order rate constant (kobs) of 2.0 × 10−3·min−1. Full article
(This article belongs to the Special Issue Current Trends in Colloidal Nanocrystals)
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Open AccessArticle Synthesis of Ordered Mesoporous CuO/CeO2 Composite Frameworks as Anode Catalysts for Water Oxidation
Nanomaterials 2015, 5(4), 1971-1984; doi:10.3390/nano5041971
Received: 29 September 2015 / Revised: 9 November 2015 / Accepted: 10 November 2015 / Published: 17 November 2015
Cited by 11 | PDF Full-text (1861 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Cerium-rich metal oxide materials have recently emerged as promising candidates for the photocatalytic oxygen evolution reaction (OER). In this article, we report the synthesis of ordered mesoporous CuO/CeO2 composite frameworks with different contents of copper(II) oxide and demonstrate their activity for photocatalytic
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Cerium-rich metal oxide materials have recently emerged as promising candidates for the photocatalytic oxygen evolution reaction (OER). In this article, we report the synthesis of ordered mesoporous CuO/CeO2 composite frameworks with different contents of copper(II) oxide and demonstrate their activity for photocatalytic O2 production via UV-Vis light-driven oxidation of water. Mesoporous CuO/CeO2 materials have been successfully prepared by a nanocasting route, using mesoporous silica as a rigid template. X-ray diffraction, electron transmission microscopy and N2 porosimetry characterization of the as-prepared products reveal a mesoporous structure composed of parallel arranged nanorods, with a large surface area and a narrow pore size distribution. The molecular structure and optical properties of the composite materials were investigated with Raman and UV-Vis/NIR diffuse reflectance spectroscopy. Catalytic results indicated that incorporation of CuO clusters in the CeO2 lattice improved the photochemical properties. As a result, the CuO/CeO2 composite catalyst containing ~38 wt % CuO reaches a high O2 evolution rate of ~19.6 µmol·h−1 (or 392 µmol·h−1·g−1) with an apparent quantum efficiency of 17.6% at λ = 365 ± 10 nm. This OER activity compares favorably with that obtained from the non-porous CuO/CeO2 counterpart (~1.3 µmol·h−1) and pure mesoporous CeO2 (~1 µmol·h−1). Full article
(This article belongs to the Special Issue Frontiers in Mesoporous Nanomaterials)
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Open AccessArticle Lithium-Excess Research of Cathode Material Li2MnTiO4 for Lithium-Ion Batteries
Nanomaterials 2015, 5(4), 1985-1994; doi:10.3390/nano5041985
Received: 15 October 2015 / Accepted: 16 November 2015 / Published: 20 November 2015
Cited by 15 | PDF Full-text (3519 KB) | HTML Full-text | XML Full-text
Abstract
Lithium-excess and nano-sized Li2+xMn1x/2TiO4 (x = 0, 0.2, 0.4) cathode materials were synthesized via a sol-gel method. The X-ray diffraction (XRD) experiments indicate that the obtained main phases of Li2.0MnTiO4 and
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Lithium-excess and nano-sized Li2+xMn1x/2TiO4 (x = 0, 0.2, 0.4) cathode materials were synthesized via a sol-gel method. The X-ray diffraction (XRD) experiments indicate that the obtained main phases of Li2.0MnTiO4 and the lithium-excess materials are monoclinic and cubic, respectively. The scanning electron microscope (SEM) images show that the as-prepared particles are well distributed and the primary particles have an average size of about 20–30 nm. The further electrochemical tests reveal that the charge-discharge performance of the material improves remarkably with the lithium content increasing. Particularly, the first discharging capacity at the current of 30 mA g−1 increases from 112.2 mAh g−1 of Li2.0MnTiO4 to 187.5 mAh g−1 of Li2.4Mn0.8TiO4. In addition, the ex situ XRD experiments indicate that the monoclinic Li2MnTiO4 tends to transform to an amorphous state with the extraction of lithium ions, while the cubic Li2MnTiO4 phase shows better structural reversibility and stability. Full article
(This article belongs to the Special Issue Nanostructured Materials for Li-Ion Batteries and Beyond)
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Open AccessArticle Electrochemical Characterization of Graphene and MWCNT Screen-Printed Electrodes Modified with AuNPs for Laccase Biosensor Development
Nanomaterials 2015, 5(4), 1995-2006; doi:10.3390/nano5041995
Received: 22 September 2015 / Accepted: 17 November 2015 / Published: 20 November 2015
Cited by 12 | PDF Full-text (276 KB) | HTML Full-text | XML Full-text
Abstract
The aim of this work is to show how the integration of gold nanoparticles (AuNPs) into multi-wall-carbon-nanotubes (MWCNTs) based screen-printed electrodes and into graphene-based screen-printed electrodes (GPHs) could represent a potential way to further enhance the electrochemical properties of those electrodes based on
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The aim of this work is to show how the integration of gold nanoparticles (AuNPs) into multi-wall-carbon-nanotubes (MWCNTs) based screen-printed electrodes and into graphene-based screen-printed electrodes (GPHs) could represent a potential way to further enhance the electrochemical properties of those electrodes based on nanoparticles. Laccase from Trametes versicolor (TvL) was immobilized over MWCNTs and GPH previously modified with AuNPs (of 5 and 10 nm). The characterization of the modified electrode surface has been carried out by cyclic voltammetry. The results showed that the use of AuNPs for modification of both graphene and MWCNTs screen-printed electrode surfaces would increase the electrochemical performances of the electrodes. MWCNTs showed better results than GPH in terms of higher electroactive area formation after modification with AuNPs. The two modified nanostructured electrodes were successively proven to efficiently immobilize the TvL; the electrochemical sensing properties of the GPH- and MWCNT-based AuNPs-TvL biosensors were investigated by choosing 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic-acid diammonium salt (ABTS), catechol and caffeic acid as laccase mediators; and the kinetic parameters of the laccase biosensor were carefully evaluated. Full article
(This article belongs to the Special Issue Nanomaterials for Biosensing Applications)
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Open AccessArticle Nanostructuring of Palladium with Low-Temperature Helium Plasma
Nanomaterials 2015, 5(4), 2007-2018; doi:10.3390/nano5042007
Received: 13 October 2015 / Revised: 12 November 2015 / Accepted: 20 November 2015 / Published: 25 November 2015
Cited by 7 | PDF Full-text (12052 KB) | HTML Full-text | XML Full-text
Abstract
Impingement of high fluxes of helium ions upon metals at elevated temperatures has given rise to the growth of nanostructured layers on the surface of several metals, such as tungsten and molybdenum. These nanostructured layers grow from the bulk material and have greatly
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Impingement of high fluxes of helium ions upon metals at elevated temperatures has given rise to the growth of nanostructured layers on the surface of several metals, such as tungsten and molybdenum. These nanostructured layers grow from the bulk material and have greatly increased surface area over that of a not nanostructured surface. They are also superior to deposited nanostructures due to a lack of worries over adhesion and differences in material properties. Several palladium samples of varying thickness were biased and exposed to a helium helicon plasma. The nanostructures were characterized as a function of the thickness of the palladium layer and of temperature. Bubbles of ~100 nm in diameter appear to be integral to the nanostructuring process. Nanostructured palladium is also shown to have better catalytic activity than not nanostructured palladium. Full article
(This article belongs to the Special Issue Plasma Nanoengineering and Nanofabrication)
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Open AccessArticle Performance Evaluation of a Nanofluid-Based Direct Absorption Solar Collector with Parabolic Trough Concentrator
Nanomaterials 2015, 5(4), 2131-2147; doi:10.3390/nano5042131
Received: 2 October 2015 / Accepted: 26 November 2015 / Published: 4 December 2015
Cited by 8 | PDF Full-text (627 KB) | HTML Full-text | XML Full-text
Abstract
Application of solar collectors for hot water supply, space heating, and cooling plays a significant role in reducing building energy consumption. For conventional solar collectors, solar radiation is absorbed by spectral selective coating on the collectors’ tube/plate wall. The poor durability of the
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Application of solar collectors for hot water supply, space heating, and cooling plays a significant role in reducing building energy consumption. For conventional solar collectors, solar radiation is absorbed by spectral selective coating on the collectors’ tube/plate wall. The poor durability of the coating can lead to an increased manufacturing cost and unreliability for a solar collector operated at a higher temperature. Therefore, a novel nanofluid-based direct absorption solar collector (NDASC) employing uncoated collector tubes has been proposed, and its operating characteristics for medium-temperature solar collection were theoretically and experimentally studied in this paper. CuO/oil nanofluid was prepared and used as working fluid of the NDASC. The heat-transfer mechanism of the NDASC with parabolic trough concentrator was theoretically evaluated and compared with a conventional indirect absorption solar collector (IASC). The theoretical analysis results suggested that the fluid’s temperature distribution in the NDASC was much more uniform than that in the IASC, and an enhanced collection efficiency could be achieved for the NDASC operated within a preferred working temperature range. To demonstrate the feasibility of the proposed NDASC, experimental performances of an NDASC and an IASC with the same parabolic trough concentrator were furthermore evaluated and comparatively discussed. Full article
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Open AccessArticle Utilization of Enzyme-Immobilized Mesoporous Silica Nanocontainers (IBN-4) in Prodrug-Activated Cancer Theranostics
Nanomaterials 2015, 5(4), 2169-2191; doi:10.3390/nano5042169
Received: 25 September 2015 / Accepted: 26 November 2015 / Published: 4 December 2015
Cited by 8 | PDF Full-text (2586 KB) | HTML Full-text | XML Full-text
Abstract
To develop a carrier for use in enzyme prodrug therapy, Horseradish peroxidase (HRP) was immobilized onto mesoporous silica nanoparticles (IBN-4: Institute of Bioengineering and Nanotechnology), where the nanoparticle surfaces were functionalized with 3-aminopropyltrimethoxysilane and further conjugated with glutaraldehyde. Consequently, the enzymes could be
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To develop a carrier for use in enzyme prodrug therapy, Horseradish peroxidase (HRP) was immobilized onto mesoporous silica nanoparticles (IBN-4: Institute of Bioengineering and Nanotechnology), where the nanoparticle surfaces were functionalized with 3-aminopropyltrimethoxysilane and further conjugated with glutaraldehyde. Consequently, the enzymes could be stabilized in nanochannels through the formation of covalent imine bonds. This strategy was used to protect HRP from immune exclusion, degradation and denaturation under biological conditions. Furthermore, immobilization of HRP in the nanochannels of IBN-4 nanomaterials exhibited good functional stability upon repetitive use and long-term storage (60 days) at 4 °C. The generation of functionalized and HRP-immobilized nanomaterials was further verified using various characterization techniques. The possibility of using HRP-encapsulated IBN-4 materials in prodrug cancer therapy was also demonstrated by evaluating their ability to convert a prodrug (indole-3- acetic acid (IAA)) into cytotoxic radicals, which triggered tumor cell apoptosis in human colon carcinoma (HT-29 cell line) cells. A lactate dehydrogenase (LDH) assay revealed that cells could be exposed to the IBN-4 nanocomposites without damaging their membranes, confirming apoptotic cell death. In summary, we demonstrated the potential of utilizing large porous mesoporous silica nanomaterials (IBN-4) as enzyme carriers for prodrug therapy. Full article
(This article belongs to the Special Issue Frontiers in Mesoporous Nanomaterials)
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Open AccessArticle Morphological, Chemical Surface, and Diffusive Transport Characterizations of a Nanoporous Alumina Membrane
Nanomaterials 2015, 5(4), 2192-2202; doi:10.3390/nano5042192
Received: 27 September 2015 / Accepted: 24 November 2015 / Published: 5 December 2015
Cited by 4 | PDF Full-text (2781 KB) | HTML Full-text | XML Full-text
Abstract
Synthesis of a nanoporous alumina membrane (NPAM) by the two-step anodization method and its morphological and chemical surface characterization by analyzing Scanning Electron Microscopy (SEM) micrographs and X-Ray Photoelectron Spectroscopy (XPS) spectra is reported. Influence of electrical and diffusive effects on the NaCl
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Synthesis of a nanoporous alumina membrane (NPAM) by the two-step anodization method and its morphological and chemical surface characterization by analyzing Scanning Electron Microscopy (SEM) micrographs and X-Ray Photoelectron Spectroscopy (XPS) spectra is reported. Influence of electrical and diffusive effects on the NaCl transport across the membrane nanopores is determined from salt diffusion measurements performed with a wide range of NaCl concentrations, which allows the estimation of characteristic electrochemical membrane parameters such as the NaCl diffusion coefficient and the concentration of fixed charges in the membrane, by using an appropriated model and the membrane geometrical parameters (porosity and pore length). These results indicate a reduction of ~70% in the value of the NaCl diffusion coefficient through the membrane pores with respect to solution. The transport number of ions in the membrane pores (Na+ and Cl, respectively) were determined from concentration potential measurements, and the effect of concentration-polarization at the membrane surfaces was also considered by comparing concentration potential values obtained with stirred solutions (550 rpm) and without stirring. From both kinds of results, a value higher than 0.05 M NaCl for the feed solution seems to be necessary to neglect the contribution of electrical interactions in the diffusive transport. Full article
(This article belongs to the Special Issue Frontiers in Mesoporous Nanomaterials)
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Open AccessArticle Hydrothermal Synthesis of Ultrasmall Pt Nanoparticles as Highly Active Electrocatalysts for Methanol Oxidation
Nanomaterials 2015, 5(4), 2203-2211; doi:10.3390/nano5042203
Received: 31 October 2015 / Revised: 20 November 2015 / Accepted: 25 November 2015 / Published: 8 December 2015
Cited by 6 | PDF Full-text (1916 KB) | HTML Full-text | XML Full-text
Abstract
Ultrasmall nanoparticles, with sizes in the 1–3 nm range, exhibit unique properties distinct from those of free molecules and larger-sized nanoparticles. Demonstrating that the hydrothermal method can serve as a facile method for the synthesis of platinum nanoparticles, we successfully synthesized ultrasmall Pt
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Ultrasmall nanoparticles, with sizes in the 1–3 nm range, exhibit unique properties distinct from those of free molecules and larger-sized nanoparticles. Demonstrating that the hydrothermal method can serve as a facile method for the synthesis of platinum nanoparticles, we successfully synthesized ultrasmall Pt nanoparticles with an average size of 2.45 nm, with the aid of poly(vinyl pyrrolidone) (PVP) as reducing agents and capping agents. Because of the size effect, these ultrasmall Pt nanoparticles exhibit a high activity toward the methanol oxidation reaction. Full article
(This article belongs to the Special Issue Nanoparticles for Catalysis) Printed Edition available
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Open AccessFeature PaperArticle Structural and Morphological Tuning of LiCoPO4 Materials Synthesized by Solvo-Thermal Methods for Li-Cell Applications
Nanomaterials 2015, 5(4), 2212-2230; doi:10.3390/nano5042212
Received: 14 October 2015 / Revised: 25 November 2015 / Accepted: 27 November 2015 / Published: 10 December 2015
Cited by 6 | PDF Full-text (3462 KB) | HTML Full-text | XML Full-text
Abstract
Olivine-type lithium metal phosphates (LiMPO4) are promising cathode materials for lithium-ion batteries. LiFePO4 (LFP) is commonly used in commercial Li-ion cells but the Fe3+/Fe2+ couple can be usefully substituted with Mn3+/Mn2+, Co3+
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Olivine-type lithium metal phosphates (LiMPO4) are promising cathode materials for lithium-ion batteries. LiFePO4 (LFP) is commonly used in commercial Li-ion cells but the Fe3+/Fe2+ couple can be usefully substituted with Mn3+/Mn2+, Co3+/Co2+, or Ni3+/Ni2+, in order to obtain higher redox potentials. In this communication we report a systematic analysis of the synthesis condition of LiCoPO4 (LCP) using a solvo-thermal route at low temperature, the latter being a valuable candidate to overcome the theoretical performances of LFP. In fact, LCP shows higher working potential (4.8 V vs. 3.6 V) compared to LFP and similar theoretical capacity (167 mAh·g−1). Our goal is to show the effect of the synthesis condition of the ability of LCP to reversibly cycle lithium in electrochemical cells. LCP samples have been prepared through a solvo-thermal method in aqueous-non aqueous solvent blends. Different Co2+ salts have been used to study the effect of the anion on the crystal growth as well as the effect of solution acidity, temperature and reaction time. Materials properties have been characterized by Fast-Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopies. The correlation between structure/morphology and electrochemical performances has been investigated by galvanostatic charge-discharge cycles. Full article
(This article belongs to the Special Issue Nanostructured Materials for Li-Ion Batteries and Beyond)
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Open AccessArticle Simulation of the Impact of Si Shell Thickness on the Performance of Si-Coated Vertically Aligned Carbon Nanofiber as Li-Ion Battery Anode
Nanomaterials 2015, 5(4), 2268-2278; doi:10.3390/nano5042268
Received: 12 October 2015 / Revised: 7 December 2015 / Accepted: 9 December 2015 / Published: 15 December 2015
Cited by 1 | PDF Full-text (1981 KB) | HTML Full-text | XML Full-text
Abstract
Micro- and nano-structured electrodes have the potential to improve the performance of Li-ion batteries by increasing the surface area of the electrode and reducing the diffusion distance required by the charged carriers. We report the numerical simulation of Lithium-ion batteries with the anode
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Micro- and nano-structured electrodes have the potential to improve the performance of Li-ion batteries by increasing the surface area of the electrode and reducing the diffusion distance required by the charged carriers. We report the numerical simulation of Lithium-ion batteries with the anode made of core-shell heterostructures of silicon-coated carbon nanofibers. We show that the energy capacity can be significantly improved by reducing the thickness of the silicon anode to the dimension comparable or less than the Li-ion diffusion length inside silicon. The results of simulation indicate that the contraction of the silicon electrode thickness during the battery discharge process commonly found in experiments also plays a major role in the increase of the energy capacity. Full article
(This article belongs to the Special Issue Nanostructured Materials for Li-Ion Batteries and Beyond)
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Open AccessFeature PaperArticle Nanoscience Supporting the Research on the Negative Electrodes of Li-Ion Batteries
Nanomaterials 2015, 5(4), 2279-2301; doi:10.3390/nano5042279
Received: 28 October 2015 / Revised: 30 November 2015 / Accepted: 2 December 2015 / Published: 16 December 2015
Cited by 4 | PDF Full-text (3186 KB) | HTML Full-text | XML Full-text
Abstract
Many efforts are currently made to increase the limited capacity of Li-ion batteries using carbonaceous anodes. The way to reach this goal is to move to nano-structured material because the larger surface to volume ratio of particles and the reduction of the electron
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Many efforts are currently made to increase the limited capacity of Li-ion batteries using carbonaceous anodes. The way to reach this goal is to move to nano-structured material because the larger surface to volume ratio of particles and the reduction of the electron and Li path length implies a larger specific capacity. Additionally, nano-particles can accommodate such a dilatation/contraction during cycling, resulting in a calendar life compatible with a commercial use. In this review attention is focused on carbon, silicon, and Li4Ti5O12 materials, because they are the most promising for applications. Full article
(This article belongs to the Special Issue Nanostructured Materials for Li-Ion Batteries and Beyond)
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Open AccessArticle Mesoporous Silica Nanoparticles Loaded with Cisplatin and Phthalocyanine for Combination Chemotherapy and Photodynamic Therapy in vitro
Nanomaterials 2015, 5(4), 2302-2316; doi:10.3390/nano5042302
Received: 7 October 2015 / Revised: 3 December 2015 / Accepted: 10 December 2015 / Published: 16 December 2015
Cited by 12 | PDF Full-text (1862 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Mesoporous silica nanoparticles (MSNs) have been synthesized and loaded with both aluminum chloride phthalocyanine (AlClPc) and cisplatin as combinatorial therapeutics for treating cancer. The structural and photophysical properties of the MSN materials were characterized by different spectroscopic and microscopic techniques. Intracellular uptake and
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Mesoporous silica nanoparticles (MSNs) have been synthesized and loaded with both aluminum chloride phthalocyanine (AlClPc) and cisplatin as combinatorial therapeutics for treating cancer. The structural and photophysical properties of the MSN materials were characterized by different spectroscopic and microscopic techniques. Intracellular uptake and cytotoxicity were evaluated in human cervical cancer (HeLa) cells by confocal laser scanning microscopy (CLSM) and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assays, respectively. The CLSM experiments showed that the MSN materials can be readily internalized in HeLa cells. The cytotoxic experiments demonstrated that, after light exposure, the combination of both AlClPc and cisplatin compounds in the same MSN platform potentiate the toxic effect against HeLa cells in comparison to the control AlClPc-MSN and cisplatin-MSN materials. These results show the potential of using MSN platforms as nanocarriers for combination photodynamic and chemotherapies to treat cancer. Full article
(This article belongs to the Special Issue Nanoparticles in Theranostics)
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Open AccessArticle Nanocarriers for DNA Vaccines: Co-Delivery of TLR-9 and NLR-2 Ligands Leads to Synergistic Enhancement of Proinflammatory Cytokine Release
Nanomaterials 2015, 5(4), 2317-2334; doi:10.3390/nano5042317
Received: 22 October 2015 / Revised: 23 November 2015 / Accepted: 2 December 2015 / Published: 17 December 2015
Cited by 1 | PDF Full-text (788 KB) | HTML Full-text | XML Full-text
Abstract
Adjuvants enhance immunogenicity of vaccines through either targeted antigen delivery or stimulation of immune receptors. Three cationic nanoparticle formulations were evaluated for their potential as carriers for a DNA vaccine, and muramyl dipeptide (MDP) as immunostimulatory agent, to induce and increase immunogenicity of
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Adjuvants enhance immunogenicity of vaccines through either targeted antigen delivery or stimulation of immune receptors. Three cationic nanoparticle formulations were evaluated for their potential as carriers for a DNA vaccine, and muramyl dipeptide (MDP) as immunostimulatory agent, to induce and increase immunogenicity of Mycobacterium tuberculosis antigen encoding plasmid DNA (pDNA). The formulations included (1) trimethyl chitosan (TMC) nanoparticles, (2) a squalene-in-water nanoemulsion, and (3) a mineral oil-in-water nanoemulsion. The adjuvant effect of the pDNA-nanocomplexes was evaluated by serum antibody analysis in immunized mice. All three carriers display a strong adjuvant effect, however, only TMC nanoparticles were capable to bias immune responses towards Th1. pDNA naturally contains immunostimulatory unmethylated CpG motifs that are recognized by Toll-like receptor 9 (TLR-9). In mechanistic in vitro studies, activation of TLR-9 and the ability to enhance immunogenicity by simultaneously targeting TLR-9 and NOD-like receptor 2 (NLR-2) was determined by proinflammatory cytokine release in RAW264.7 macrophages. pDNA in combination with MDP was shown to significantly increase proinflammatory cytokine release in a synergistic manner, dependent on NLR-2 activation. In summary, novel pDNA-Ag85A loaded nanoparticle formulations, which induce antigen specific immune responses in mice were developed, taking advantage of the synergistic combinations of TLR and NLR agonists to increase the adjuvanticity of the carriers used. Full article
(This article belongs to the Special Issue Nanoparticles Assisted Drug Delivery)
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Open AccessArticle Facile and Eco-Friendly Synthesis of Finger-Like Co3O4 Nanorods for Electrochemical Energy Storage
Nanomaterials 2015, 5(4), 2335-2347; doi:10.3390/nano5042335
Received: 15 October 2015 / Revised: 2 December 2015 / Accepted: 14 December 2015 / Published: 17 December 2015
Cited by 2 | PDF Full-text (827 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Co3O4 nanorods were prepared by a facile hydrothermal method. Eco-friendly deionized water rather than organic solvent was used as the hydrothermal media. The as-prepared Co3O4 nanorods are composed of many nanoparticles of 30–50 nm in diameter, forming
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Co3O4 nanorods were prepared by a facile hydrothermal method. Eco-friendly deionized water rather than organic solvent was used as the hydrothermal media. The as-prepared Co3O4 nanorods are composed of many nanoparticles of 30–50 nm in diameter, forming a finger-like morphology. The Co3O4 electrode shows a specific capacitance of 265 F g−1 at 2 mV s−1 in a supercapacitor and delivers an initial specific discharge capacity as high as 1171 mAh g−1 at a current density of 50 mA g−1 in a lithium ion battery. Excellent cycling stability and electrochemical reversibility of the Co3O4 electrode were also obtained. Full article
(This article belongs to the Special Issue Nanostructured Materials for Li-Ion Batteries and Beyond)
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Open AccessArticle Size Effect of Ordered Mesoporous Carbon Nanospheres for Anodes in Li-Ion Battery
Nanomaterials 2015, 5(4), 2348-2358; doi:10.3390/nano5042348
Received: 7 November 2015 / Revised: 8 December 2015 / Accepted: 10 December 2015 / Published: 18 December 2015
Cited by 5 | PDF Full-text (546 KB) | HTML Full-text | XML Full-text
Abstract
The present work demonstrates the application of various sizes of ordered mesoporous carbon nanospheres (OMCS) with diameters of 46–130 nm as an active anode material for Li-ion batteries (LIB). The physical and chemical properties of OMCS have been evaluated by performing scanning electron
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The present work demonstrates the application of various sizes of ordered mesoporous carbon nanospheres (OMCS) with diameters of 46–130 nm as an active anode material for Li-ion batteries (LIB). The physical and chemical properties of OMCS have been evaluated by performing scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption-desorption analysis; small-angle scattering system (SAXS) and X-ray diffraction (XRD). The electrochemical analysis of using various sizes of OMCS as anode materials showed high capacity and rate capability with the specific capacity up to 560 mA·h·g−1 at 0.1 C after 85 cycles. In terms of performance at high current rate compared to other amorphous carbonaceous materials; a stable and extremely high specific capacity of 240 mA·h·g−1 at 5 C after 15 cycles was achieved. Such excellent performance is mainly attributed to the suitable particle size distribution of OMCS and intimate contact between OMCS and conductive additives; which can be supported from the TEM images. Results obtained from this study clearly indicate the excellence of size distribution of highly integrated mesoporous structure of carbon nanospheres for LIB application. Full article
(This article belongs to the Special Issue Nanostructured Materials for Li-Ion Batteries and Beyond)
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Open AccessArticle Non-Cytotoxic Quantum Dot–Chitosan Nanogel Biosensing Probe for Potential Cancer Targeting Agent
Nanomaterials 2015, 5(4), 2359-2379; doi:10.3390/nano5042359
Received: 16 November 2015 / Revised: 4 December 2015 / Accepted: 15 December 2015 / Published: 18 December 2015
Cited by 3 | PDF Full-text (2255 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Quantum dot (Qdot) biosensors have consistently provided valuable information to researchers about cellular activity due to their unique fluorescent properties. Many of the most popularly used Qdots contain cadmium, posing the risk of toxicity that could negate their attractive optical properties. The design
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Quantum dot (Qdot) biosensors have consistently provided valuable information to researchers about cellular activity due to their unique fluorescent properties. Many of the most popularly used Qdots contain cadmium, posing the risk of toxicity that could negate their attractive optical properties. The design of a non-cytotoxic probe usually involves multiple components and a complex synthesis process. In this paper, the design and synthesis of a non-cytotoxic Qdot-chitosan nanogel composite using straight-forward cyanogen bromide (CNBr) coupling is reported. The probe was characterized by spectroscopy (UV-Vis, fluorescence), microscopy (Fluorescence, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Dynamic Light Scattering. This activatable (“OFF”/“ON”) probe contains a core–shell Qdot (CdS:Mn/ZnS) capped with dopamine, which acts as a fluorescence quencher and a model drug. Dopamine capped “OFF” Qdots can undergo ligand exchange with intercellular glutathione, which turns the Qdots “ON” to restore fluorescence. These Qdots were then coated with chitosan (natural biocompatible polymer) functionalized with folic acid (targeting motif) and Fluorescein Isothiocyanate (FITC; fluorescent dye). To demonstrate cancer cell targetability, the interaction of the probe with cells that express different folate receptor levels was analyzed, and the cytotoxicity of the probe was evaluated on these cells and was shown to be nontoxic even at concentrations as high as 100 mg/L. Full article
(This article belongs to the Special Issue Nanoparticles Assisted Drug Delivery)
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Open AccessCommunication Freestanding rGO-SWNT-STN Composite Film as an Anode for Li Ion Batteries with High Energy and Power Densities
Nanomaterials 2015, 5(4), 2380-2390; doi:10.3390/nano5042380
Received: 13 October 2015 / Revised: 27 November 2015 / Accepted: 2 December 2015 / Published: 18 December 2015
Cited by 2 | PDF Full-text (1760 KB) | HTML Full-text | XML Full-text
Abstract
Freestanding Si-Ti-Ni alloy particles/reduced graphene oxide/single wall carbon nanotube composites have been prepared as an anode for lithium ion batteries via a simple filtration method. This composite electrode showed a 9% increase in reversible capacity, a two-fold higher cycle retention at 50 cycles
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Freestanding Si-Ti-Ni alloy particles/reduced graphene oxide/single wall carbon nanotube composites have been prepared as an anode for lithium ion batteries via a simple filtration method. This composite electrode showed a 9% increase in reversible capacity, a two-fold higher cycle retention at 50 cycles and a two-fold higher rate capability at 2 C compared to pristine Si-Ti-Ni (STN) alloy electrodes. These improvements were attributed to the suppression of the pulverization of the STN active material by the excellent mechanical properties of the reduced graphene oxide-single wall carbon nanotube networks and the enhanced kinetics associated with both electron and Li ion transport. Full article
(This article belongs to the Special Issue Nanostructured Materials for Li-Ion Batteries and Beyond)
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Review

Jump to: Research

Open AccessReview Metal Oxide Nanomaterial QNAR Models: Available Structural Descriptors and Understanding of Toxicity Mechanisms
Nanomaterials 2015, 5(4), 1620-1637; doi:10.3390/nano5041620
Received: 11 September 2015 / Revised: 3 October 2015 / Accepted: 3 October 2015 / Published: 12 October 2015
Cited by 3 | PDF Full-text (433 KB) | HTML Full-text | XML Full-text
Abstract
Metal oxide nanomaterials are widely used in various areas; however, the divergent published toxicology data makes it difficult to determine whether there is a risk associated with exposure to metal oxide nanomaterials. The application of quantitative structure activity relationship (QSAR) modeling in metal
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Metal oxide nanomaterials are widely used in various areas; however, the divergent published toxicology data makes it difficult to determine whether there is a risk associated with exposure to metal oxide nanomaterials. The application of quantitative structure activity relationship (QSAR) modeling in metal oxide nanomaterials toxicity studies can reduce the need for time-consuming and resource-intensive nanotoxicity tests. The nanostructure and inorganic composition of metal oxide nanomaterials makes this approach different from classical QSAR study; this review lists and classifies some structural descriptors, such as size, cation charge, and band gap energy, in recent metal oxide nanomaterials quantitative nanostructure activity relationship (QNAR) studies and discusses the mechanism of metal oxide nanomaterials toxicity based on these descriptors and traditional nanotoxicity tests. Full article
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Open AccessReview Mesoporous Transition Metal Oxides for Supercapacitors
Nanomaterials 2015, 5(4), 1667-1689; doi:10.3390/nano5041667
Received: 18 August 2015 / Revised: 8 October 2015 / Accepted: 8 October 2015 / Published: 14 October 2015
Cited by 33 | PDF Full-text (3355 KB) | HTML Full-text | XML Full-text
Abstract
Recently, transition metal oxides, such as ruthenium oxide (RuO2), manganese dioxide (MnO2), nickel oxides (NiO) and cobalt oxide (Co3O4), have been widely investigated as electrode materials for pseudo-capacitors. In particular, these metal oxides with mesoporous
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Recently, transition metal oxides, such as ruthenium oxide (RuO2), manganese dioxide (MnO2), nickel oxides (NiO) and cobalt oxide (Co3O4), have been widely investigated as electrode materials for pseudo-capacitors. In particular, these metal oxides with mesoporous structures have become very hot nanomaterials in the field of supercapacitors owing to their large specific surface areas and suitable pore size distributions. The high specific capacities of these mesoporous metal oxides are resulted from the effective contacts between electrode materials and electrolytes as well as fast transportation of ions and electrons in the bulk of electrode and at the interface of electrode and electrolyte. During the past decade, many achievements on mesoporous transition metal oxides have been made. In this mini-review, we select several typical nanomaterials, such as RuO2, MnO2, NiO, Co3O4 and nickel cobaltite (NiCo2O4), and briefly summarize the recent research progress of these mesoporous transition metal oxides-based electrodes in the field of supercapacitors. Full article
(This article belongs to the Special Issue Frontiers in Mesoporous Nanomaterials)
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Open AccessReview Multifunctional Nanomaterials and Their Applications in Drug Delivery and Cancer Therapy
Nanomaterials 2015, 5(4), 1690-1703; doi:10.3390/nano5041690
Received: 20 August 2015 / Revised: 23 September 2015 / Accepted: 1 October 2015 / Published: 14 October 2015
Cited by 9 | PDF Full-text (730 KB) | HTML Full-text | XML Full-text
Abstract
The field of nanotechnology has led to the development of many innovative strategies for effective detection and treatment of cancer, overcoming limitations associated with conventional cancer diagnosis and therapy. Multifunctional nanoparticle systems can integrate imaging, targeting and treatment moieties on the surface and
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The field of nanotechnology has led to the development of many innovative strategies for effective detection and treatment of cancer, overcoming limitations associated with conventional cancer diagnosis and therapy. Multifunctional nanoparticle systems can integrate imaging, targeting and treatment moieties on the surface and in the core, resulting in targeted delivery of the imaging or treatment modalities, specifically to the tumor. Multifunctional nanoparticles also enable simultaneous delivery of multiple treatment agents, resulting in effective combinatorial therapeutic regimens against cancer. In this review, various multifunctional nanoparticle systems that feature a variety of targeting moieties for in vitro and/or in vivo cancer imaging and therapy are discussed. Full article
(This article belongs to the Special Issue Nanoparticles Assisted Drug Delivery)
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Open AccessReview Single-Walled Carbon Nanohorns for Energy Applications
Nanomaterials 2015, 5(4), 1732-1755; doi:10.3390/nano5041732
Received: 28 August 2015 / Revised: 26 September 2015 / Accepted: 2 October 2015 / Published: 21 October 2015
Cited by 14 | PDF Full-text (2400 KB) | HTML Full-text | XML Full-text
Abstract
With the growth of the global economy and population, the demand for energy is increasing sharply. The development of environmentally a benign and reliable energy supply is very important and urgent. Single-walled carbon nanohorns (SWCNHs), which have a horn-shaped tip at the top
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With the growth of the global economy and population, the demand for energy is increasing sharply. The development of environmentally a benign and reliable energy supply is very important and urgent. Single-walled carbon nanohorns (SWCNHs), which have a horn-shaped tip at the top of single-walled nanotube, have emerged as exceptionally promising nanomaterials due to their unique physical and chemical properties since 1999. The high purity and thermal stability, combined with microporosity and mesoporosity, high surface area, internal pore accessibility, and multiform functionalization make SWCNHs promising candidates in many applications, such as environment restoration, gas storage, catalyst support or catalyst, electrochemical biosensors, drug carrier systems, magnetic resonance analysis and so on. The aim of this review is to provide a comprehensive overview of SWCNHs in energy applications, including energy conversion and storage. The commonly adopted method to access SWCNHs, their structural modifications, and their basic properties are included, and the emphasis is on their application in different devices such as fuel cells, dye-sensitized solar cells, supercapacitors, Li-ion batteries, Li-S batteries, hydrogen storage, biofuel cells and so forth. Finally, a perspective on SWCNHs’ application in energy is presented. Full article
(This article belongs to the Special Issue Nanomaterials for Energy and Sustainability Applications)
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Open AccessReview Enhancing Solar Cell Efficiency Using Photon Upconversion Materials
Nanomaterials 2015, 5(4), 1782-1809; doi:10.3390/nano5041782
Received: 27 August 2015 / Revised: 10 October 2015 / Accepted: 10 October 2015 / Published: 27 October 2015
Cited by 11 | PDF Full-text (3293 KB) | HTML Full-text | XML Full-text
Abstract
Photovoltaic cells are able to convert sunlight into electricity, providing enough of the most abundant and cleanest energy to cover our energy needs. However, the efficiency of current photovoltaics is significantly impeded by the transmission loss of sub-band-gap photons. Photon upconversion is a
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Photovoltaic cells are able to convert sunlight into electricity, providing enough of the most abundant and cleanest energy to cover our energy needs. However, the efficiency of current photovoltaics is significantly impeded by the transmission loss of sub-band-gap photons. Photon upconversion is a promising route to circumvent this problem by converting these transmitted sub-band-gap photons into above-band-gap light, where solar cells typically have high quantum efficiency. Here, we summarize recent progress on varying types of efficient upconversion materials as well as their outstanding uses in a series of solar cells, including silicon solar cells (crystalline and amorphous), gallium arsenide (GaAs) solar cells, dye-sensitized solar cells, and other types of solar cells. The challenge and prospect of upconversion materials for photovoltaic applications are also discussed Full article
(This article belongs to the Special Issue Nanostructured Solar Cells) Printed Edition available
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Open AccessReview Gold Nanotheranostics: Proof-of-Concept or Clinical Tool?
Nanomaterials 2015, 5(4), 1853-1879; doi:10.3390/nano5041853
Received: 22 August 2015 / Revised: 4 October 2015 / Accepted: 27 October 2015 / Published: 3 November 2015
Cited by 18 | PDF Full-text (704 KB) | HTML Full-text | XML Full-text
Abstract
Nanoparticles have been making their way in biomedical applications and personalized medicine, allowing for the coupling of diagnostics and therapeutics into a single nanomaterial—nanotheranostics. Gold nanoparticles, in particular, have unique features that make them excellent nanomaterials for theranostics, enabling the integration of targeting,
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Nanoparticles have been making their way in biomedical applications and personalized medicine, allowing for the coupling of diagnostics and therapeutics into a single nanomaterial—nanotheranostics. Gold nanoparticles, in particular, have unique features that make them excellent nanomaterials for theranostics, enabling the integration of targeting, imaging and therapeutics in a single platform, with proven applicability in the management of heterogeneous diseases, such as cancer. In this review, we focus on gold nanoparticle-based theranostics at the lab bench, through pre-clinical and clinical stages. With few products facing clinical trials, much remains to be done to effectively assess the real benefits of nanotheranostics at the clinical level. Hence, we also discuss the efforts currently being made to translate nanotheranostics into the market, as well as their commercial impact. Full article
(This article belongs to the Special Issue Nanoparticles in Theranostics)
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Open AccessReview Smart Mesoporous Nanomaterials for Antitumor Therapy
Nanomaterials 2015, 5(4), 1906-1937; doi:10.3390/nano5041906
Received: 28 September 2015 / Revised: 23 October 2015 / Accepted: 3 November 2015 / Published: 6 November 2015
Cited by 13 | PDF Full-text (1622 KB) | HTML Full-text | XML Full-text
Abstract
The use of nanomaterials for the treatment of solid tumours is receiving increasing attention by the scientific community. Among them, mesoporous silica nanoparticles (MSNs) exhibit unique features that make them suitable nanocarriers to host, transport and protect drug molecules until the target is
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The use of nanomaterials for the treatment of solid tumours is receiving increasing attention by the scientific community. Among them, mesoporous silica nanoparticles (MSNs) exhibit unique features that make them suitable nanocarriers to host, transport and protect drug molecules until the target is reached. It is possible to incorporate different targeting ligands to the outermost surface of MSNs to selectively drive the drugs to the tumour tissues. To prevent the premature release of the cargo entrapped in the mesopores, it is feasible to cap the pore entrances using stimuli-responsive nanogates. Therefore, upon exposure to internal (pH, enzymes, glutathione, etc.) or external (temperature, light, magnetic field, etc.) stimuli, the pore opening takes place and the release of the entrapped cargo occurs. These smart MSNs are capable of selectively reaching and accumulating at the target tissue and releasing the entrapped drug in a specific and controlled fashion, constituting a promising alternative to conventional chemotherapy, which is typically associated with undesired side effects. In this review, we overview the recent advances reported by the scientific community in developing MSNs for antitumor therapy. We highlight the possibility to design multifunctional nanosystems using different therapeutic approaches aimed at increasing the efficacy of the antitumor treatment. Full article
(This article belongs to the Special Issue Frontiers in Mesoporous Nanomaterials)
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Open AccessReview Recent Advance on Mesoporous Silica Nanoparticles-Based Controlled Release System: Intelligent Switches Open up New Horizon
Nanomaterials 2015, 5(4), 2019-2053; doi:10.3390/nano5042019
Received: 30 September 2015 / Revised: 25 October 2015 / Accepted: 28 October 2015 / Published: 25 November 2015
Cited by 6 | PDF Full-text (3176 KB) | HTML Full-text | XML Full-text
Abstract
Mesoporous silica nanoparticle (MSN)-based intelligent transport systems have attracted many researchers’ attention due to the characteristics of uniform pore and particle size distribution, good biocompatibility, high surface area, and versatile functionalization, which have led to their widespread application in diverse areas. In the
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Mesoporous silica nanoparticle (MSN)-based intelligent transport systems have attracted many researchers’ attention due to the characteristics of uniform pore and particle size distribution, good biocompatibility, high surface area, and versatile functionalization, which have led to their widespread application in diverse areas. In the past two decades, many kinds of smart controlled release systems were prepared with the development of brilliant nano-switches. This article reviews and discusses the advantages of MSN-based controlled release systems. Meanwhile, the switching mechanisms based on different types of stimulus response are systematically analyzed and summarized. Additionally, the application fields of these devices are further discussed. Obviously, the recent evolution of smart nano-switches promoted the upgrading of the controlled release system from the simple “separated” switch to the reversible, multifunctional, complicated logical switches and selective switches. Especially the free-blockage switches, which are based on hydrophobic/hydrophilic conversion, have been proposed and designed in the last two years. The prospects and directions of this research field are also briefly addressed, which could be better used to promote the further development of this field to meet the needs of mankind. Full article
(This article belongs to the Special Issue Frontiers in Mesoporous Nanomaterials)
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Open AccessFeature PaperReview Composites of Polymer Hydrogels and Nanoparticulate Systems for Biomedical and Pharmaceutical Applications
Nanomaterials 2015, 5(4), 2054-2130; doi:10.3390/nano5042054
Received: 20 October 2015 / Revised: 18 November 2015 / Accepted: 20 November 2015 / Published: 3 December 2015
Cited by 24 | PDF Full-text (6363 KB) | HTML Full-text | XML Full-text
Abstract
Due to their unique structures and properties, three-dimensional hydrogels and nanostructured particles have been widely studied and shown a very high potential for medical, therapeutic and diagnostic applications. However, hydrogels and nanoparticulate systems have respective disadvantages that limit their widespread applications. Recently, the
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Due to their unique structures and properties, three-dimensional hydrogels and nanostructured particles have been widely studied and shown a very high potential for medical, therapeutic and diagnostic applications. However, hydrogels and nanoparticulate systems have respective disadvantages that limit their widespread applications. Recently, the incorporation of nanostructured fillers into hydrogels has been developed as an innovative means for the creation of novel materials with diverse functionality in order to meet new challenges. In this review, the fundamentals of hydrogels and nanoparticles (NPs) were briefly discussed, and then we comprehensively summarized recent advances in the design, synthesis, functionalization and application of nanocomposite hydrogels with enhanced mechanical, biological and physicochemical properties. Moreover, the current challenges and future opportunities for the use of these promising materials in the biomedical sector, especially the nanocomposite hydrogels produced from hydrogels and polymeric NPs, are discussed. Full article
(This article belongs to the Special Issue Nanoparticles Assisted Drug Delivery)
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Open AccessReview Upconverting NIR Photons for Bioimaging
Nanomaterials 2015, 5(4), 2148-2168; doi:10.3390/nano5042148
Received: 15 October 2015 / Accepted: 27 November 2015 / Published: 4 December 2015
Cited by 12 | PDF Full-text (2863 KB) | HTML Full-text | XML Full-text
Abstract
Lanthanide-doped upconverting nanoparticles (UCNPs) possess uniqueanti-Stokes optical properties, in which low energy near-infrared (NIR) photons can beconverted into high energy UV, visible, shorter NIR emission via multiphoton upconversionprocesses. Due to the rapid development of synthesis chemistry, lanthanide-doped UCNPscan be fabricated with narrow distribution
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Lanthanide-doped upconverting nanoparticles (UCNPs) possess uniqueanti-Stokes optical properties, in which low energy near-infrared (NIR) photons can beconverted into high energy UV, visible, shorter NIR emission via multiphoton upconversionprocesses. Due to the rapid development of synthesis chemistry, lanthanide-doped UCNPscan be fabricated with narrow distribution and tunable multi-color optical properties. Theseunique attributes grant them unique NIR-driven imaging/drug delivery/therapeuticapplications, especially in the cases of deep tissue environments. In this brief review, weintroduce both the basic concepts of and recent progress with UCNPs in material engineeringand theranostic applications in imaging, molecular delivery, and tumor therapeutics. The aimof this brief review is to address the most typical progress in basic mechanism, materialdesign as bioimaging tools. Full article
(This article belongs to the Special Issue Nanoparticles in Bioimaging)
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Open AccessReview Magnetic Nanoparticles Cross the Blood-Brain Barrier: When Physics Rises to a Challenge
Nanomaterials 2015, 5(4), 2231-2248; doi:10.3390/nano5042231
Received: 29 October 2015 / Revised: 25 November 2015 / Accepted: 8 December 2015 / Published: 11 December 2015
Cited by 6 | PDF Full-text (1539 KB) | HTML Full-text | XML Full-text
Abstract
The blood-brain barrier is a physical and physiological barrier that protects the brain from toxic substances within the bloodstream and helps maintain brain homeostasis. It also represents the main obstacle in the treatment of many diseases of the central nervous system. Among the
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The blood-brain barrier is a physical and physiological barrier that protects the brain from toxic substances within the bloodstream and helps maintain brain homeostasis. It also represents the main obstacle in the treatment of many diseases of the central nervous system. Among the different approaches employed to overcome this barrier, the use of nanoparticles as a tool to enhance delivery of therapeutic molecules to the brain is particularly promising. There is special interest in the use of magnetic nanoparticles, as their physical characteristics endow them with additional potentially useful properties. Following systemic administration, a magnetic field applied externally can mediate the capacity of magnetic nanoparticles to permeate the blood-brain barrier. Meanwhile, thermal energy released by magnetic nanoparticles under the influence of radiofrequency radiation can modulate blood-brain barrier integrity, increasing its permeability. In this review, we present the strategies that use magnetic nanoparticles, specifically iron oxide nanoparticles, to enhance drug delivery to the brain. Full article
(This article belongs to the Special Issue Nanoparticles in Theranostics)
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Open AccessReview Electric Field-Responsive Mesoporous Suspensions: A Review
Nanomaterials 2015, 5(4), 2249-2267; doi:10.3390/nano5042249
Received: 30 September 2015 / Revised: 6 December 2015 / Accepted: 9 December 2015 / Published: 15 December 2015
Cited by 9 | PDF Full-text (2337 KB) | HTML Full-text | XML Full-text
Abstract
This paper briefly reviews the fabrication and electrorheological (ER) characteristics of mesoporous materials and their nanocomposites with conducting polymers under an applied electric field when dispersed in an insulating liquid. Smart fluids of electrically-polarizable particles exhibit a reversible and tunable phase transition from
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This paper briefly reviews the fabrication and electrorheological (ER) characteristics of mesoporous materials and their nanocomposites with conducting polymers under an applied electric field when dispersed in an insulating liquid. Smart fluids of electrically-polarizable particles exhibit a reversible and tunable phase transition from a liquid-like to solid-like state in response to an external electric field of various strengths, and have potential applications in a variety of active control systems. The ER properties of these mesoporous suspensions are explained further according to their dielectric spectra in terms of the flow curve, dynamic moduli, and yield stress. Full article
(This article belongs to the Special Issue Frontiers in Mesoporous Nanomaterials)
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