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Nanomaterials, Volume 6, Issue 11 (November 2016)

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Open AccessFeature PaperReview Exchange Bias Effects in Iron Oxide-Based Nanoparticle Systems
Nanomaterials 2016, 6(11), 221; https://doi.org/10.3390/nano6110221
Received: 24 August 2016 / Revised: 29 October 2016 / Accepted: 2 November 2016 / Published: 23 November 2016
Cited by 16 | PDF Full-text (6960 KB) | HTML Full-text | XML Full-text
Abstract
The exploration of exchange bias (EB) on the nanoscale provides a novel approach to improving the anisotropic properties of magnetic nanoparticles for prospective applications in nanospintronics and nanomedicine. However, the physical origin of EB is not fully understood. Recent advances in chemical synthesis
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The exploration of exchange bias (EB) on the nanoscale provides a novel approach to improving the anisotropic properties of magnetic nanoparticles for prospective applications in nanospintronics and nanomedicine. However, the physical origin of EB is not fully understood. Recent advances in chemical synthesis provide a unique opportunity to explore EB in a variety of iron oxide-based nanostructures ranging from core/shell to hollow and hybrid composite nanoparticles. Experimental and atomistic Monte Carlo studies have shed light on the roles of interface and surface spins in these nanosystems. This review paper aims to provide a thorough understanding of the EB and related phenomena in iron oxide-based nanoparticle systems, knowledge of which is essential to tune the anisotropic magnetic properties of exchange-coupled nanoparticle systems for potential applications. Full article
(This article belongs to the Special Issue Functional Magnetic Nanoparticles in Nanomedicine)
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Open AccessArticle Electrochemical Synthesis of Polypyrrole, Reduced Graphene Oxide, and Gold Nanoparticles Composite and Its Application to Hydrogen Peroxide Biosensor
Nanomaterials 2016, 6(11), 220; https://doi.org/10.3390/nano6110220
Received: 9 October 2016 / Revised: 6 November 2016 / Accepted: 16 November 2016 / Published: 21 November 2016
Cited by 6 | PDF Full-text (2613 KB) | HTML Full-text | XML Full-text
Abstract
Here we report a facile eco-friendly one-step electrochemical approach for the fabrication of a polypyrrole (PPy), reduced graphene oxide (RGO), and gold nanoparticles (nanoAu) biocomposite on a glassy carbon electrode (GCE). The electrochemical behaviors of PPy–RGO–nanoAu and its application to electrochemical detection of
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Here we report a facile eco-friendly one-step electrochemical approach for the fabrication of a polypyrrole (PPy), reduced graphene oxide (RGO), and gold nanoparticles (nanoAu) biocomposite on a glassy carbon electrode (GCE). The electrochemical behaviors of PPy–RGO–nanoAu and its application to electrochemical detection of hydrogen peroxide were investigated by cyclic voltammetry. Graphene oxide and pyrrole monomer were first mixed and casted on the surface of a cleaned GCE. After an electrochemical processing consisting of the electrooxidation of pyrrole monomer and simultaneous electroreduction of graphene oxide and auric ions (Au3+) in aqueous solution, a PPy–RGO–nanoAu biocomposite was synthesized on GCE. Each component of PPy–RGO–nanoAu is electroactive without non-electroactive substance. The obtained PPy–RGO–nanoAu/GCE exhibited high electrocatalytic activity toward hydrogen peroxide, which allows the detection of hydrogen peroxide at a negative potential of about −0.62 V vs. SCE. The amperometric responses of the biosensor displayed a sensitivity of 40 µA/mM, a linear range of 32 µM–2 mM, and a detection limit of 2.7 µM (signal-to-noise ratio = 3) with good stability and acceptable reproducibility and selectivity. The results clearly demonstrate the potential of the as-prepared PPy–RGO–nanoAu biocomposite for use as a highly electroactive matrix for an amperometric biosensor. Full article
(This article belongs to the Special Issue Nanocomposite Coatings)
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Open AccessArticle The Dispersion State of Tangled Multi-Walled Carbon Nanotubes Affects Their Cytotoxicity
Nanomaterials 2016, 6(11), 219; https://doi.org/10.3390/nano6110219
Received: 5 August 2016 / Revised: 5 November 2016 / Accepted: 11 November 2016 / Published: 19 November 2016
Cited by 2 | PDF Full-text (1463 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The medical applications of carbon nanotubes (CNTs) have garnered much attention. However, evaluating the safety of CNTs remains difficult, and no consensus has been reached. Moreover, assessing the biosafety of multi-walled CNTs (MWCNTs), which can become tangled during manufacturing, is challenging because they
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The medical applications of carbon nanotubes (CNTs) have garnered much attention. However, evaluating the safety of CNTs remains difficult, and no consensus has been reached. Moreover, assessing the biosafety of multi-walled CNTs (MWCNTs), which can become tangled during manufacturing, is challenging because they do not readily disperse. We studied how the dispersion state of tangled MWCNTs affects their cytotoxicity, using three sonicators. Flotube 9110 (FT9110), tangled MWCNTs, were dispersed in two dispersants (fetal bovine serum and polysorbate 80) using a new type of sonicator (PR-1) and two conventional sonicators. The size and cytotoxicity of the dispersed FT9110 were measured using the BEAS-2B human bronchial epithelial cell line. The PR-1 dispersed the FT9110 to agglomerates <200 nm in diameter; FT9110 dispersed with the PR-1 did not show cytotoxicity regardless of dispersant. The other sonicators dispersed the FT9110 to particles >1000 nm in diameter, and cytotoxicity depended on the dispersant. We found that excluding cells adhered to agglomerated FT9110 before evaluating cytotoxicity can lead to false-positive results. The PR-1 sonicator dispersed tangled FT9110 to many single fibers, which showed lower cytotoxicity than conventionally-sonicated MWCNTs. We suggest that dispersion state should be accounted for when evaluating the cytotoxicity of MWCNTs. Full article
(This article belongs to the Special Issue Cytotoxicity of Nanoparticles)
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Open AccessArticle A Facile Method to In-Situ Synthesize Porous Ni2GeO4 Nano-Sheets on Nickel Foam as Advanced Anode Electrodes for Li-Ion Batteries
Nanomaterials 2016, 6(11), 218; https://doi.org/10.3390/nano6110218
Received: 14 September 2016 / Revised: 25 October 2016 / Accepted: 28 October 2016 / Published: 19 November 2016
Cited by 2 | PDF Full-text (4389 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A strategy for growth of porous Ni2GeO4 nanosheets on conductive nickel (Ni) foam with robust adhesion as a high-performance electrode for Li-ion batteries is proposed and realized, through a facile two-step method. It involves the low temperature hydro-thermal synthesis of
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A strategy for growth of porous Ni2GeO4 nanosheets on conductive nickel (Ni) foam with robust adhesion as a high-performance electrode for Li-ion batteries is proposed and realized, through a facile two-step method. It involves the low temperature hydro-thermal synthesis of bimetallic (Ni, Ge) hydroxide nanosheets precursor on Ni foam substrates and subsequent thermal transformation to porous Ni2GeO4 nanosheets. The as-prepared Ni2GeO4 nanosheets possess many interparticle mesopores with a size range from 5 to 15 nm. The hierarchical structure of porous Ni2GeO4 nanosheets supported by Ni foam promises fast electron and ion transport, large electroactive surface area, and excellent structural stability. The efficacy of the specially designed structure is demonstrated by the superior electrochemical performance of the generated Ni2GeO4 nanosheets including a high capacity of 1.8 mA·h·cm−2 at a current density of 50 μA·cm−2, good cycle stability, and high power capability at room temperature. Because of simple conditions, this fabrication strategy may be easily extended to other mixed metal oxides (MxGeOy). Full article
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Open AccessArticle Electrostatic Self-Assembly of Diamond Nanoparticles onto Al- and N-Polar Sputtered Aluminum Nitride Surfaces
Nanomaterials 2016, 6(11), 217; https://doi.org/10.3390/nano6110217
Received: 11 October 2016 / Accepted: 10 November 2016 / Published: 17 November 2016
Cited by 2 | PDF Full-text (1991 KB) | HTML Full-text | XML Full-text
Abstract
Electrostatic self-assembly of diamond nanoparticles (DNPs) onto substrate surfaces (so-called nanodiamond seeding) is a notable technique, enabling chemical vapor deposition (CVD) of nanocrystalline diamond thin films on non-diamond substrates. In this study, we examine this technique onto differently polarized (either Al- or N-polar)
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Electrostatic self-assembly of diamond nanoparticles (DNPs) onto substrate surfaces (so-called nanodiamond seeding) is a notable technique, enabling chemical vapor deposition (CVD) of nanocrystalline diamond thin films on non-diamond substrates. In this study, we examine this technique onto differently polarized (either Al- or N-polar) c-axis oriented sputtered aluminum nitride (AlN) film surfaces. This investigation shows that Al-polar films, as compared to N-polar ones, obtain DNPs with higher density and more homogeneously on their surfaces. The origin of these differences in density and homogeneity is discussed based on the hydrolysis behavior of AlN surfaces in aqueous suspensions. Full article
(This article belongs to the Special Issue Diamond and Its Related Nanostructured Thin Films/Coatings)
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Open AccessArticle A Targeted Nanoprobe Based on Carbon Nanotubes-Natural Biopolymer Chitosan Composites
Nanomaterials 2016, 6(11), 216; https://doi.org/10.3390/nano6110216
Received: 9 September 2016 / Revised: 8 November 2016 / Accepted: 9 November 2016 / Published: 17 November 2016
Cited by 1 | PDF Full-text (2498 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A novel targeting theranostic nanoprobe based on single-walled carbon nanotubes (SWCNTs)-natural biopolymer chitosan composites was developed for cancer cell targeting imaging and fluorescence imaging-guided photodynamic therapy. First, chitosan was respectively conjugated with a tumor-homing molecule folic acid, or a photosensitizing drug pyropheophorbide a
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A novel targeting theranostic nanoprobe based on single-walled carbon nanotubes (SWCNTs)-natural biopolymer chitosan composites was developed for cancer cell targeting imaging and fluorescence imaging-guided photodynamic therapy. First, chitosan was respectively conjugated with a tumor-homing molecule folic acid, or a photosensitizing drug pyropheophorbide a using a water-soluble carbodiimide coupling chemistry. Chitosan was fluorescently labeled by fluorescein isothiocyanate via the covalently linkage of the isothiocyanate group with the amino group. Second, SWCNTs were sonicated in the functional chitosan aqueous solution for 6 h at room temperature in order to obtain the nanoprobe (PPa/FITC-SWCNT-FA). The as-prepared nanoprobe has been characterized with transmission electron microscope, confocal microscopy, and cell cytotoxicity tests. Chitosan was decorated onto SWCNTs resulting in the water-dispersible PPa/FITC-SWCNT-FA, and can be selectively transported inside folate receptor-positive tumor cell with good targeting imaging. PPa/FITC-SWCNT-FA exhibited low dark toxicity about 7%–13%, and high phototoxicity about 60%–74% against HeLa cells upon a 635 nm laser irradiation, indicating satisfying biocompatibility and antitumor activity. These results suggest the study could offer a feasible alternative to presently available nanoparticle-based theranostic agents. Full article
(This article belongs to the Special Issue Multifunctional Polymer-Based Nanocomposites)
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Open AccessArticle Photoelectrochemical Performance Observed in Mn-Doped BiFeO3 Heterostructured Thin Films
Nanomaterials 2016, 6(11), 215; https://doi.org/10.3390/nano6110215
Received: 9 October 2016 / Revised: 8 November 2016 / Accepted: 11 November 2016 / Published: 16 November 2016
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Abstract
Pure BiFeO3 and heterostructured BiFeO3/BiFe0.95Mn0.05O3 (5% Mn-doped BiFeO3) thin films have been prepared by a chemical deposition method. The band structures and photosensitive properties of these films have been investigated elaborately. Pure BiFeO
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Pure BiFeO3 and heterostructured BiFeO3/BiFe0.95Mn0.05O3 (5% Mn-doped BiFeO3) thin films have been prepared by a chemical deposition method. The band structures and photosensitive properties of these films have been investigated elaborately. Pure BiFeO3 films showed stable and strong response to photo illumination (open circuit potential kept −0.18 V, short circuit photocurrent density was −0.023 mA·cm−2). By Mn doping, the energy band positions shifted, resulting in a smaller band gap of BiFe0.95Mn0.05O3 layer and an internal field being built in the BiFeO3/BiFe0.95Mn0.05O3 interface. BiFeO3/BiFe0.95Mn0.05O3 and BiFe0.95Mn0.05O3 thin films demonstrated poor photo activity compared with pure BiFeO3 films, which can be explained by the fact that Mn doping brought in a large amount of defects in the BiFe0.95Mn0.05O3 layers, causing higher carrier combination and correspondingly suppressing the photo response, and this negative influence was more considerable than the positive effects provided by the band modulation. Full article
(This article belongs to the Special Issue Nanoscale in Photocatalysis)
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Open AccessFeature PaperArticle Innovative Self-Cleaning and Biocompatible Polyester Textiles Nano-Decorated with Fe–N-Doped Titanium Dioxide
Nanomaterials 2016, 6(11), 214; https://doi.org/10.3390/nano6110214
Received: 13 October 2016 / Revised: 3 November 2016 / Accepted: 7 November 2016 / Published: 15 November 2016
Cited by 3 | PDF Full-text (5239 KB) | HTML Full-text | XML Full-text
Abstract
The development of innovative technologies to modify natural textiles holds an important impact for medical applications, including the prevention of contamination with microorganisms, particularly in the hospital environment. In our study, Fe and N co-doped TiO2 nanoparticles have been obtained via the
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The development of innovative technologies to modify natural textiles holds an important impact for medical applications, including the prevention of contamination with microorganisms, particularly in the hospital environment. In our study, Fe and N co-doped TiO2 nanoparticles have been obtained via the hydrothermal route, at moderate temperature, followed by short thermal annealing at 400 °C. These particles were used to impregnate polyester (PES) materials which have been evaluated for their morphology, photocatalytic performance, antimicrobial activity against bacterial reference strains, and in vitro biocompatibility on human skin fibroblasts. Microscopic examination and quantitative assays have been used to evaluate the cellular morphology and viability, cell membrane integrity, and inflammatory response. All treated PES materials specifically inhibited the growth of Gram-negative bacilli strains after 15 min of contact, being particularly active against Pseudomonas aeruginosa. PES fabrics treated with photocatalysts did not affect cell membrane integrity nor induce inflammatory processes, proving good biocompatibility. These results demonstrate that the treatment of PES materials with TiO2-1% Fe–N particles could provide novel biocompatible fabrics with short term protection against microbial colonization, demonstrating their potential for the development of innovative textiles that could be used in biomedical applications for preventing patients’ accidental contamination with microorganisms from the hospital environment. Full article
(This article belongs to the Special Issue Nanoarchitectonics: A Novel Approach for Drug Delivery and Targeting)
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Open AccessFeature PaperReview Recent Advances in Chiral Nematic Structure and Iridescent Color of Cellulose Nanocrystal Films
Nanomaterials 2016, 6(11), 213; https://doi.org/10.3390/nano6110213
Received: 29 September 2016 / Revised: 4 November 2016 / Accepted: 4 November 2016 / Published: 14 November 2016
Cited by 17 | PDF Full-text (3071 KB) | HTML Full-text | XML Full-text
Abstract
One unique property of cellulose nanocrystals (CNC) is their property of forming suspensions with chiral nematic order. This order can be preserved in films cast from the suspensions, raising the possibility of applications as photonic materials and templates. However, it has proved difficult
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One unique property of cellulose nanocrystals (CNC) is their property of forming suspensions with chiral nematic order. This order can be preserved in films cast from the suspensions, raising the possibility of applications as photonic materials and templates. However, it has proved difficult to generate uniform, well-ordered chiral nematic materials from CNC. Recently, the importance of kinetic arrest due to gel formation in the later stages of evaporation has been recognized as a key step in film formation. In this brief review, recent developments regarding the structure of chiral nematic suspensions and films as monitored by polarized light microscopy are outlined, and attention is drawn to the importance of shear forces on the self-organization process. Full article
(This article belongs to the Special Issue Emerging Applications of Cellulose Nanocrystal and Its Composites)
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Open AccessArticle Electrochemical and Capacitive Properties of Carbon Dots/Reduced Graphene Oxide Supercapacitors
Nanomaterials 2016, 6(11), 212; https://doi.org/10.3390/nano6110212
Received: 20 August 2016 / Revised: 4 November 2016 / Accepted: 7 November 2016 / Published: 14 November 2016
Cited by 7 | PDF Full-text (3489 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
There is much recent interest in graphene-based composite electrode materials because of their excellent mechanical strengths, high electron mobilities, and large specific surface areas. These materials are good candidates for applications in supercapacitors. In this work, a new graphene-based electrode material for supercapacitors
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There is much recent interest in graphene-based composite electrode materials because of their excellent mechanical strengths, high electron mobilities, and large specific surface areas. These materials are good candidates for applications in supercapacitors. In this work, a new graphene-based electrode material for supercapacitors was fabricated by anchoring carbon dots (CDs) on reduced graphene oxide (rGO). The capacitive properties of electrodes in aqueous electrolytes were systematically studied by galvanostatic charge-discharge measurements, cyclic voltammetry, and electrochemical impedance spectroscopy. The capacitance of rGO was improved when an appropriate amount of CDs were added to the material. The CD/rGO electrode exhibited a good reversibility, excellent rate capability, fast charge transfer, and high specific capacitance in 1 M H2SO4. Its capacitance was as high as 211.9 F/g at a current density of 0.5 A/g. This capacitance was 74.3% higher than that of a pristine rGO electrode (121.6 F/g), and the capacitance of the CD/rGO electrode retained 92.8% of its original value after 1000 cycles at a CDs-to-rGO ratio of 5:1. Full article
(This article belongs to the Special Issue Nanomaterials Based Fuel Cells and Supercapacitors)
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Open AccessFeature PaperReview Design and Electrochemical Study of Platinum-Based Nanomaterials for Sensitive Detection of Nitric Oxide in Biomedical Applications
Nanomaterials 2016, 6(11), 211; https://doi.org/10.3390/nano6110211
Received: 21 September 2016 / Revised: 4 November 2016 / Accepted: 7 November 2016 / Published: 14 November 2016
Cited by 7 | PDF Full-text (3759 KB) | HTML Full-text | XML Full-text
Abstract
The extensive physiological and regulatory roles of nitric oxide (NO) have spurred the development of NO sensors, which are of critical importance in neuroscience and various medical applications. The development of electrochemical NO sensors is of significant importance, and has garnered a tremendous
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The extensive physiological and regulatory roles of nitric oxide (NO) have spurred the development of NO sensors, which are of critical importance in neuroscience and various medical applications. The development of electrochemical NO sensors is of significant importance, and has garnered a tremendous amount of attention due to their high sensitivity and selectivity, rapid response, low cost, miniaturization, and the possibility of real-time monitoring. Nanostructured platinum (Pt)-based materials have attracted considerable interest regarding their use in the design of electrochemical sensors for the detection of NO, due to their unique properties and the potential for new and innovative applications. This review focuses primarily on advances and insights into the utilization of nanostructured Pt-based electrode materials, such as nanoporous Pt, Pt and PtAu nanoparticles, PtAu nanoparticle/reduced graphene oxide (rGO), and PtW nanoparticle/rGO-ionic liquid (IL) nanocomposites, for the detection of NO. The design, fabrication, characterization, and integration of electrochemical NO sensing performance, selectivity, and durability are addressed. The attractive electrochemical properties of Pt-based nanomaterials have great potential for increasing the competitiveness of these new sensors and open up new opportunities in the creation of novel NO-sensing technologies for biological and medical applications. Full article
(This article belongs to the Special Issue Nanostructured Biosensors 2016)
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Open AccessArticle Effect of Crystal Orientation on Self-Assembly Nanocones Formed on Tungsten Surface Induced by Helium Ion Irradiation and Annealing
Nanomaterials 2016, 6(11), 210; https://doi.org/10.3390/nano6110210
Received: 20 September 2016 / Revised: 6 November 2016 / Accepted: 9 November 2016 / Published: 12 November 2016
Cited by 1 | PDF Full-text (2571 KB) | HTML Full-text | XML Full-text
Abstract
The self-assembly nanocone structures on the surface of polycrystalline tungsten were created by He+ ion irradiation and then annealing, and the resulting topography and morphology were characterized using atomic force microscopy and scanning electron microscopy. The cross-sectional samples of the self-assembly nanocones
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The self-assembly nanocone structures on the surface of polycrystalline tungsten were created by He+ ion irradiation and then annealing, and the resulting topography and morphology were characterized using atomic force microscopy and scanning electron microscopy. The cross-sectional samples of the self-assembly nanocones were prepared using an in situ–focused ion beam and then observed using transmission electron microscopy. The self-assembly nanocones were induced by the combined effect of He+ ion irradiation, the annealing process and the chromium impurity. The distribution characteristics, density and morphology of the nanocones exhibited a distinct difference relating to the crystal orientations. The highest density of the nanocones was observed on the grain surface with a (1 1 1) orientation, with the opposite for that with a (0 0 1) orientation and a medium value on the (1 0 1)-oriented grain. The size of the self-assembly nanocones increased with increasing the annealing time which met a power-law relationship. Irradiation-induced defects acted as the nucleation locations of the protrusions which attracted the migration of the tiny amount of chromium atoms. Under the action of temperature, the protrusions finally evolved into the nanocones. Full article
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Open AccessFeature PaperReview Green Synthesis of Iron Nanoparticles and Their Environmental Applications and Implications
Nanomaterials 2016, 6(11), 209; https://doi.org/10.3390/nano6110209
Received: 12 August 2016 / Revised: 17 October 2016 / Accepted: 7 November 2016 / Published: 12 November 2016
Cited by 20 | PDF Full-text (1156 KB) | HTML Full-text | XML Full-text
Abstract
Recent advances in nanoscience and nanotechnology have also led to the development of novel nanomaterials, which ultimately increase potential health and environmental hazards. Interest in developing environmentally benign procedures for the synthesis of metallic nanoparticles has been increased. The purpose is to minimize
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Recent advances in nanoscience and nanotechnology have also led to the development of novel nanomaterials, which ultimately increase potential health and environmental hazards. Interest in developing environmentally benign procedures for the synthesis of metallic nanoparticles has been increased. The purpose is to minimize the negative impacts of synthetic procedures, their accompanying chemicals and derivative compounds. The exploitation of different biomaterials for the synthesis of nanoparticles is considered a valuable approach in green nanotechnology. Biological resources such as bacteria, algae fungi and plants have been used for the production of low-cost, energy-efficient, and nontoxic environmental friendly metallic nanoparticles. This review provides an overview of various reports of green synthesised zero valent metallic iron (ZVMI) and iron oxide (Fe2O3/Fe3O4) nanoparticles (NPs) and highlights their substantial applications in environmental pollution control. This review also summarizes the ecotoxicological impacts of green synthesised iron nanoparticles opposed to non-green synthesised iron nanoparticles. Full article
(This article belongs to the Special Issue Environmental Applications and Implications of Nanotechnology)
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Open AccessArticle Oral Toxicity and Intestinal Transport Mechanism of Colloidal Gold Nanoparticle-Treated Red Ginseng
Nanomaterials 2016, 6(11), 208; https://doi.org/10.3390/nano6110208
Received: 4 September 2016 / Revised: 29 October 2016 / Accepted: 3 November 2016 / Published: 11 November 2016
Cited by 1 | PDF Full-text (1286 KB) | HTML Full-text | XML Full-text
Abstract
(1) Background: Application of nanotechnology or nanomaterials in agricultural food crops has attracted increasing attention with regard to improving crop production, quality, and nutrient utilization. Gold nanoparticles (Au-NPs) have been reported to enhance seed yield, germination rate, and anti-oxidant potential in food crops,
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(1) Background: Application of nanotechnology or nanomaterials in agricultural food crops has attracted increasing attention with regard to improving crop production, quality, and nutrient utilization. Gold nanoparticles (Au-NPs) have been reported to enhance seed yield, germination rate, and anti-oxidant potential in food crops, raising concerns about their toxicity potential. In this study, we evaluated the oral toxicity of red ginseng exposed to colloidal Au-NPs during cultivation (G-red ginseng) in rats and their intestinal transport mechanism. (2) Methods: 14-day repeated oral administration of G-red ginseng extract to rats was performed, and body weight, hematological, serum biochemical, and histopathological values were analyzed. An in vitro model of human intestinal follicle-associated epithelium (FAE) and an intestinal epithelial monolayer system were used for intestinal transport mechanistic study. (3) Results: No remarkable oral toxicity of G-red ginseng extract in rats was found, and Au-NPs did not accumulate in any organ, although Au-NP transfer to G-red ginseng and some increased saponin levels were confirmed. Au-NPs were transcytozed by microfold (M) cells, but not by a paracellular pathway in the intestinal epithelium. (4) Conclusion: These findings suggest great potential of Au-NPs for agricultural food crops at safe levels. Further study is required to elucidate the functional effects of Au-NPs on ginseng and long-term toxicity. Full article
(This article belongs to the Special Issue Nanomaterials in Food Safety)
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Open AccessArticle Hybrid Nanostructures Containing Sulfadiazine Modified Chitosan as Antimicrobial Drug Carriers
Nanomaterials 2016, 6(11), 207; https://doi.org/10.3390/nano6110207
Received: 24 August 2016 / Revised: 3 November 2016 / Accepted: 4 November 2016 / Published: 10 November 2016
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Abstract
Chitosan (CH) nanofibrous structures containing sulfadiazine (SDZ) or sulfadiazine modified chitosan (SCH) in the form of functional nanoparticles attached to nanofibers (hybrid nanostructures) were obtained by mono-axial and coaxial electrospinning. The mono-axial design consisted of a SDZ/CH mixture solution fed through a single
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Chitosan (CH) nanofibrous structures containing sulfadiazine (SDZ) or sulfadiazine modified chitosan (SCH) in the form of functional nanoparticles attached to nanofibers (hybrid nanostructures) were obtained by mono-axial and coaxial electrospinning. The mono-axial design consisted of a SDZ/CH mixture solution fed through a single nozzle while the coaxial design consisted of SCH and CH solutions separately supplied to the inner and outer nozzle (or in reverse order). The CH ability to form nanofibers assured the formation of a nanofiber mesh, while SDZ and SCH, both in form of suspensions in the electrospun solution, assured the formation of active nanoparticles which remained attached to the CH nanofiber mesh after the electrospinning process. The obtained nanostructures were morphologically characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The SDZ release profiles and kinetics were analyzed. The SDZ or SCH nanoparticles loosely attached at the surface of the nanofibers, provide a burst release in the first 20 min, which is important to stop the possible initial infection in a wound, while the SDZ and SCH from the nanoparticles which are better confined (or even encapsulated) into the CH nanofibers would be slowly released with the erosion/disruption of the CH nanofiber mesh. Full article
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