Next Issue
Previous Issue

Table of Contents

Nanomaterials, Volume 6, Issue 6 (June 2016)

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
View options order results:
result details:
Displaying articles 1-25
Export citation of selected articles as:

Editorial

Jump to: Research, Review, Other

Open AccessEditorial Nanoparticles in Bioimaging
Nanomaterials 2016, 6(6), 105; doi:10.3390/nano6060105
Received: 3 June 2016 / Revised: 3 June 2016 / Accepted: 3 June 2016 / Published: 6 June 2016
PDF Full-text (147 KB) | HTML Full-text | XML Full-text
Abstract
This Special Issue of Nanomaterials is dedicated to the application of nanoparticulate materials in biological imaging.[...] Full article
(This article belongs to the Special Issue Nanoparticles in Bioimaging)
Open AccessEditorial Engineered Nanomaterials in the Environment
Nanomaterials 2016, 6(6), 106; doi:10.3390/nano6060106
Received: 3 June 2016 / Revised: 3 June 2016 / Accepted: 3 June 2016 / Published: 6 June 2016
PDF Full-text (150 KB) | HTML Full-text | XML Full-text
Abstract
This Special Issue of Nanomaterials, “Engineered Nanomaterials in the Environment”, is comprised of one communication and five research articles.[...] Full article
(This article belongs to the Special Issue Engineered Nanomaterials in the Environment)

Research

Jump to: Editorial, Review, Other

Open AccessArticle Ultraviolet Plasmonic Aluminium Nanoparticles for Highly Efficient Light Incoupling on Silicon Solar Cells
Nanomaterials 2016, 6(6), 95; doi:10.3390/nano6060095
Received: 31 March 2016 / Revised: 1 May 2016 / Accepted: 18 May 2016 / Published: 24 May 2016
Cited by 2 | PDF Full-text (4151 KB) | HTML Full-text | XML Full-text
Abstract
Plasmonic metal nanoparticles supporting localized surface plasmon resonances have attracted a great deal of interest in boosting the light absorption in solar cells. Among the various plasmonic materials, the aluminium nanoparticles recently have become a rising star due to their unique ultraviolet plasmonic
[...] Read more.
Plasmonic metal nanoparticles supporting localized surface plasmon resonances have attracted a great deal of interest in boosting the light absorption in solar cells. Among the various plasmonic materials, the aluminium nanoparticles recently have become a rising star due to their unique ultraviolet plasmonic resonances, low cost, earth-abundance and high compatibility with the complementary metal-oxide semiconductor (CMOS) manufacturing process. Here, we report some key factors that determine the light incoupling of aluminium nanoparticles located on the front side of silicon solar cells. We first numerically study the scattering and absorption properties of the aluminium nanoparticles and the influence of the nanoparticle shape, size, surface coverage and the spacing layer on the light incoupling using the finite difference time domain method. Then, we experimentally integrate 100-nm aluminium nanoparticles on the front side of silicon solar cells with varying silicon nitride thicknesses. This study provides the fundamental insights for designing aluminium nanoparticle-based light trapping on solar cells. Full article
(This article belongs to the Special Issue Nanostructured Solar Cells) Printed Edition available
Figures

Open AccessArticle Structural Changes Induced in Grapevine (Vitis vinifera L.) DNA by Femtosecond IR Laser Pulses: A Surface-Enhanced Raman Spectroscopic Study
Nanomaterials 2016, 6(6), 96; doi:10.3390/nano6060096
Received: 23 March 2016 / Revised: 25 April 2016 / Accepted: 17 May 2016 / Published: 25 May 2016
PDF Full-text (4076 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
In this work, surface-enhanced Raman spectra of ten genomic DNAs extracted from leaf tissues of different grapevine (Vitis vinifera L.) varieties, respectively, are analyzed in the wavenumber range 300–1800 cm−1. Furthermore, structural changes induced in grapevine genomic nucleic acids upon
[...] Read more.
In this work, surface-enhanced Raman spectra of ten genomic DNAs extracted from leaf tissues of different grapevine (Vitis vinifera L.) varieties, respectively, are analyzed in the wavenumber range 300–1800 cm−1. Furthermore, structural changes induced in grapevine genomic nucleic acids upon femtosecond (170 fs) infrared (IR) laser pulse irradiation (λ = 1100 nm) are discussed in detail for seven genomic DNAs, respectively. Surface-enhanced Raman spectroscopy (SERS) signatures, vibrational band assignments and structural characterization of genomic DNAs are reported for each case. As a general observation, the wavenumber range between 1500 and 1660 cm−1 of the spectra seems to be modified upon laser treatment. This finding could reflect changes in the base-stacking interactions in DNA. Spectral shifts are mainly attributed to purines (dA, dG) and deoxyribose. Pyrimidine residues seem to be less affected by IR femtosecond laser pulse irradiation. Furthermore, changes in the conformational properties of nucleic acid segments are observed after laser treatment. We have found that DNA isolated from Feteasca Neagra grapevine leaf tissues is the most structurally-responsive system to the femtosecond IR laser irradiation process. In addition, using unbiased computational resources by means of principal component analysis (PCA), eight different grapevine varieties were discriminated. Full article
(This article belongs to the Special Issue DNA-Based Nanotechnology)
Figures

Open AccessFeature PaperArticle Improving the Photocurrent in Quantum-Dot-Sensitized Solar Cells by Employing Alloy PbxCd1−xS Quantum Dots as Photosensitizers
Nanomaterials 2016, 6(6), 97; doi:10.3390/nano6060097
Received: 6 April 2016 / Revised: 16 May 2016 / Accepted: 20 May 2016 / Published: 25 May 2016
Cited by 4 | PDF Full-text (3335 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Ternary alloy PbxCd1−xS quantum dots (QDs) were explored as photosensitizers for quantum-dot-sensitized solar cells (QDSCs). Alloy PbxCd1−xS QDs (Pb0.54Cd0.46S, Pb0.31Cd0.69S, and Pb0.24Cd0.76
[...] Read more.
Ternary alloy PbxCd1−xS quantum dots (QDs) were explored as photosensitizers for quantum-dot-sensitized solar cells (QDSCs). Alloy PbxCd1−xS QDs (Pb0.54Cd0.46S, Pb0.31Cd0.69S, and Pb0.24Cd0.76S) were found to substantially improve the photocurrent of the solar cells compared to the single CdS or PbS QDs. Moreover, it was found that the photocurrent increases and the photovoltage decreases when the ratio of Pb in PbxCd1−xS is increased. Without surface protecting layer deposition, the highest short-circuit current density reaches 20 mA/cm2 under simulated AM 1.5 illumination (100 mW/cm2). After an additional CdS coating layer was deposited onto the PbxCd1−xS electrode, the photovoltaic performance further improved, with a photocurrent of 22.6 mA/cm2 and an efficiency of 3.2%. Full article
(This article belongs to the Special Issue Nanostructured Solar Cells) Printed Edition available
Figures

Open AccessArticle Enhancing the Photocurrent of Top-Cell by Ellipsoidal Silver Nanoparticles: Towards Current-Matched GaInP/GaInAs/Ge Triple-Junction Solar Cells
Nanomaterials 2016, 6(6), 98; doi:10.3390/nano6060098
Received: 6 April 2016 / Revised: 11 May 2016 / Accepted: 16 May 2016 / Published: 25 May 2016
Cited by 1 | PDF Full-text (2535 KB) | HTML Full-text | XML Full-text
Abstract
A way to increase the photocurrent of top-cell is crucial for current-matched and highly-efficient GaInP/GaInAs/Ge triple-junction solar cells. Herein, we demonstrate that ellipsoidal silver nanoparticles (Ag NPs) with better extinction performance and lower fabrication temperature can enhance the light harvest of GaInP/GaInAs/Ge solar
[...] Read more.
A way to increase the photocurrent of top-cell is crucial for current-matched and highly-efficient GaInP/GaInAs/Ge triple-junction solar cells. Herein, we demonstrate that ellipsoidal silver nanoparticles (Ag NPs) with better extinction performance and lower fabrication temperature can enhance the light harvest of GaInP/GaInAs/Ge solar cells compared with that of spherical Ag NPs. In this method, appropriate thermal treatment parameters for Ag NPs without inducing the dopant diffusion of the tunnel-junction plays a decisive role. Our experimental and theoretical results confirm the ellipsoidal Ag NPs annealed at 350 °C show a better extinction performance than the spherical Ag NPs annealed at 400 °C. The photovoltaic conversion efficiency of the device with ellipsoidal Ag NPs reaches 31.02%, with a nearly 5% relative improvement in comparison with the device without Ag NPs (29.54%). This function of plasmonic NPs has the potential to solve the conflict of sufficient light absorption and efficient carrier collection in GaInP top-cell devices. Full article
(This article belongs to the Special Issue Nanostructured Solar Cells) Printed Edition available
Figures

Figure 1

Open AccessArticle Synthesis of Ball-Like Ag Nanorod Aggregates for Surface-Enhanced Raman Scattering and Catalytic Reduction
Nanomaterials 2016, 6(6), 99; doi:10.3390/nano6060099
Received: 30 March 2016 / Revised: 18 May 2016 / Accepted: 18 May 2016 / Published: 25 May 2016
Cited by 3 | PDF Full-text (3806 KB) | HTML Full-text | XML Full-text
Abstract
In this work, ball-like Ag nanorod aggregates have been synthesized via a simple seed-mediated method. These Ag mesostructures were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-Vis), and X-ray diffraction (XRD). Adding a certain amount of polyvinyl pyrrolidone
[...] Read more.
In this work, ball-like Ag nanorod aggregates have been synthesized via a simple seed-mediated method. These Ag mesostructures were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-Vis), and X-ray diffraction (XRD). Adding a certain amount of polyvinyl pyrrolidone (PVP) can prolong its coagulation time. These Ag nanorod aggregates exhibit effective SERS effect, evaluated by Rhodamine 6G (R6G) and doxorubicin (DOX) as probe molecules. The limit of detection (LOD) for R6G and DOX are as low as 5 × 10−9 M and 5 × 10−6 M, respectively. Moreover, these Ag nanorod aggregates were found to be potential catalysts for the reduction of 4-nitrophenol (4-NP) in the presence of NaBH4. Full article
(This article belongs to the Special Issue Nanoparticles for Catalysis)
Figures

Figure 1

Open AccessFeature PaperArticle Fabricating Water Dispersible Superparamagnetic Iron Oxide Nanoparticles for Biomedical Applications through Ligand Exchange and Direct Conjugation
Nanomaterials 2016, 6(6), 100; doi:10.3390/nano6060100
Received: 13 April 2016 / Revised: 29 April 2016 / Accepted: 13 May 2016 / Published: 26 May 2016
Cited by 6 | PDF Full-text (2549 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Stable superparamagnetic iron oxide nanoparticles (SPIONs), which can be easily dispersed in an aqueous medium and exhibit high magnetic relaxivities, are ideal candidates for biomedical applications including contrast agents for magnetic resonance imaging. We describe a versatile methodology to render water dispersibility to
[...] Read more.
Stable superparamagnetic iron oxide nanoparticles (SPIONs), which can be easily dispersed in an aqueous medium and exhibit high magnetic relaxivities, are ideal candidates for biomedical applications including contrast agents for magnetic resonance imaging. We describe a versatile methodology to render water dispersibility to SPIONs using tetraethylene glycol (TEG)-based phosphonate ligands, which are easily introduced onto SPIONs by either a ligand exchange process of surface-anchored oleic-acid (OA) molecules or via direct conjugation. Both protocols confer good colloidal stability to SPIONs at different NaCl concentrations. A detailed characterization of functionalized SPIONs suggests that the ligand exchange method leads to nanoparticles with better magnetic properties but higher toxicity and cell death, than the direct conjugation methodology. Full article
Figures

Open AccessArticle TiAl3-TiN Composite Nanoparticles Produced by Hydrogen Plasma-Metal Reaction: Synthesis, Passivation, and Characterization
Nanomaterials 2016, 6(6), 101; doi:10.3390/nano6060101
Received: 5 April 2016 / Revised: 18 May 2016 / Accepted: 23 May 2016 / Published: 1 June 2016
Cited by 1 | PDF Full-text (2423 KB) | HTML Full-text | XML Full-text
Abstract
TiAl3 and TiN composite nanoparticles were continuously synthesized from Ti–48Al master alloy by hydrogen plasma-metal reaction in a N2, H2 and Ar atmosphere. The phase, morphology, and size of the nanoparticles were studied by X-ray diffraction (XRD) and transmission
[...] Read more.
TiAl3 and TiN composite nanoparticles were continuously synthesized from Ti–48Al master alloy by hydrogen plasma-metal reaction in a N2, H2 and Ar atmosphere. The phase, morphology, and size of the nanoparticles were studied by X-ray diffraction (XRD) and transmission electronic microscopy (TEM). X-ray photoelectron spectroscopy (XPS) and evolved gas analysis (EGA) were used to analyze the surface phase constitution and oxygen content of the nanoparticles. The as-synthesized nanopowders were mainly composed of nearly spherical TiAl3 and tetragonal TiN phases, with a mean diameter of ~42 nm and mass fractions of 49.1% and 24.3%, respectively. Passivation in the atmosphere of Ar and O2 for 24 h at room temperature led to the formation of amorphous Al2O3 shells on the TiAl3 particle surface, with a mean thickness of ~5.0 nm and a mass fraction of ~23.5%, as well as TiO2 with a mass fraction of ~3.2%. Full article
(This article belongs to the Special Issue Plasma Nanoengineering and Nanofabrication)
Figures

Open AccessArticle Fluorescent Nanocomposite of Embedded Ceria Nanoparticles in Crosslinked PVA Electrospun Nanofibers
Nanomaterials 2016, 6(6), 102; doi:10.3390/nano6060102
Received: 5 April 2016 / Revised: 9 May 2016 / Accepted: 24 May 2016 / Published: 1 June 2016
Cited by 3 | PDF Full-text (4013 KB) | HTML Full-text | XML Full-text
Abstract
This paper introduces a new fluorescent nanocomposite of electrospun biodegradable nanofibers embedded with optical nanoparticles. In detail, this work introduces the fluorescence properties of PVA nanofibers generated by the electrospinning technique with embedded cerium oxide (ceria) nanoparticles. Under near-ultra violet excitation, the synthesized
[...] Read more.
This paper introduces a new fluorescent nanocomposite of electrospun biodegradable nanofibers embedded with optical nanoparticles. In detail, this work introduces the fluorescence properties of PVA nanofibers generated by the electrospinning technique with embedded cerium oxide (ceria) nanoparticles. Under near-ultra violet excitation, the synthesized nanocomposite generates a visible fluorescent emission at 520 nm, varying its intensity peak according to the concentration of in situ embedded ceria nanoparticles. This is due to the fact that the embedded ceria nanoparticles have optical tri-valiant cerium ions, associated with formed oxygen vacancies, with a direct allowed bandgap around 3.5 eV. In addition, the impact of chemical crosslinking of the PVA on the fluorescence emission is studied in both cases of adding ceria nanoparticles in situ or of a post-synthesis addition via a spin-coating mechanism. Other optical and structural characteristics such as absorbance dispersion, direct bandgap, FTIR spectroscopy, and SEM analysis are presented. The synthesized optical nanocomposite could be helpful in different applications such as environmental monitoring and bioimaging. Full article
(This article belongs to the Special Issue Multifunctional Polymer-Based Nanocomposites)
Figures

Figure 1

Open AccessArticle Enhanced Activity of Supported Ni Catalysts Promoted by Pt for Rapid Reduction of Aromatic Nitro Compounds
Nanomaterials 2016, 6(6), 103; doi:10.3390/nano6060103
Received: 22 April 2016 / Revised: 11 May 2016 / Accepted: 13 May 2016 / Published: 4 June 2016
Cited by 5 | PDF Full-text (3535 KB) | HTML Full-text | XML Full-text
Abstract
To improve the activities of non-noble metal catalysts is highly desirable and valuable to the reduced use of noble metal resources. In this work, the supported nickel (Ni) and nickel-platinum (NiPt) nanocatalysts were derived from a layered double hydroxide/carbon composite precursor. The catalysts
[...] Read more.
To improve the activities of non-noble metal catalysts is highly desirable and valuable to the reduced use of noble metal resources. In this work, the supported nickel (Ni) and nickel-platinum (NiPt) nanocatalysts were derived from a layered double hydroxide/carbon composite precursor. The catalysts were characterized and the role of Pt was analysed using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDS) mapping, and X-ray photoelectron spectroscopy (XPS) techniques. The Ni2+ was reduced to metallic Ni0 via a self-reduction way utilizing the carbon as a reducing agent. The average sizes of the Ni particles in the NiPt catalysts were smaller than that in the supported Ni catalyst. The electronic structure of Ni was affected by the incorporation of Pt. The optimal NiPt catalysts exhibited remarkably improved activity toward the reduction of nitrophenol, which has an apparent rate constant (Ka) of 18.82 × 10−3 s−1, 6.2 times larger than that of Ni catalyst and also larger than most of the reported values of noble-metal and bimetallic catalysts. The enhanced activity could be ascribed to the modification to the electronic structure of Ni by Pt and the effect of exposed crystal planes. Full article
(This article belongs to the Special Issue Nanoparticles for Catalysis)
Figures

Open AccessArticle The Influence of Modified Silica Nanomaterials on Adult Stem Cell Culture
Nanomaterials 2016, 6(6), 104; doi:10.3390/nano6060104
Received: 2 May 2016 / Revised: 23 May 2016 / Accepted: 24 May 2016 / Published: 4 June 2016
Cited by 2 | PDF Full-text (1751 KB) | HTML Full-text | XML Full-text
Abstract
The preparation of tailored nanomaterials able to support cell growth and viability is mandatory for tissue engineering applications. In the present work, silica nanoparticles were prepared by a sol-gel procedure and were then functionalized by condensation of amino groups and by adsorption of
[...] Read more.
The preparation of tailored nanomaterials able to support cell growth and viability is mandatory for tissue engineering applications. In the present work, silica nanoparticles were prepared by a sol-gel procedure and were then functionalized by condensation of amino groups and by adsorption of silver nanoparticles. Transmission electron microscopy (TEM) imaging was used to establish the morphology and the average dimensions of about 130 nm, which were not affected by the functionalization. The three silica samples were deposited (1 mg/mL) on cover glasses, which were used as a substrate to culture adult human bone marrow-mesenchymal stem cells (hBM-MSCs) and human adipose-derived stem cells (hASCs). The good cell viability over the different silica surfaces was evaluated by monitoring the mitochondrial dehydrogenase activity. The analysis of the morphological parameters (aspect ratio, cell length, and nuclear shape Index) yielded information about the interactions of stem cells with the surface of three different nanoparticles. The data are discussed in terms of chemical properties of the surface of silica nanoparticles. Full article
(This article belongs to the Special Issue Nanomaterials for Tissue Engineering)
Figures

Open AccessFeature PaperArticle Fe3+-Doped TiO2 Nanotube Arrays on Ti-Fe Alloys for Enhanced Photoelectrocatalytic Activity
Nanomaterials 2016, 6(6), 107; doi:10.3390/nano6060107
Received: 10 May 2016 / Revised: 30 May 2016 / Accepted: 1 June 2016 / Published: 6 June 2016
Cited by 3 | PDF Full-text (4183 KB) | HTML Full-text | XML Full-text
Abstract
Highly ordered, vertically oriented Fe3+-doped TiO2 nanotube arrays (Fe-TNTs) were prepared on Ti-Fe alloy substrates with different Fe contents by the electrochemical anodization method. The as-prepared Fe-TNTs were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction
[...] Read more.
Highly ordered, vertically oriented Fe3+-doped TiO2 nanotube arrays (Fe-TNTs) were prepared on Ti-Fe alloy substrates with different Fe contents by the electrochemical anodization method. The as-prepared Fe-TNTs were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and related electrochemical techniques. XPS results demonstrated that Fe3+ ions were successfully doped into TiO2 nanotubes. The photoelectrochemical activity of Fe-TNTs was compared with that of pure TiO2 nanotube arrays (TNTs). The results showed that Fe-TNTs grown on low concentration (0.5 wt %–1 wt % Fe) Ti-Fe alloys possessed higher photocurrent density than TNTs. The Fe-TNTs grown on Ti-Fe alloy containing 0.8 wt % Fe exhibited the highest photoelectrochemical activity and the photoelectrocatalytic degradation rate of methylene blue (MB) aqueous solution was significantly higher than that of TNTs. Full article
(This article belongs to the Special Issue Nanomaterials for Electrocatalysis)
Figures

Figure 1

Open AccessFeature PaperArticle Gd-Si Oxide Nanoparticles as Contrast Agents in Magnetic Resonance Imaging
Nanomaterials 2016, 6(6), 109; doi:10.3390/nano6060109
Received: 29 March 2016 / Revised: 6 May 2016 / Accepted: 27 May 2016 / Published: 8 June 2016
PDF Full-text (4611 KB) | HTML Full-text | XML Full-text
Abstract
We describe the synthesis, characterization and application as contrast agents in magnetic resonance imaging of a novel type of magnetic nanoparticle based on Gd-Si oxide, which presents high Gd3+ atom density. For this purpose, we have used a Prussian Blue analogue as
[...] Read more.
We describe the synthesis, characterization and application as contrast agents in magnetic resonance imaging of a novel type of magnetic nanoparticle based on Gd-Si oxide, which presents high Gd3+ atom density. For this purpose, we have used a Prussian Blue analogue as the sacrificial template by reacting with soluble silicate, obtaining particles with nanorod morphology and of small size (75 nm). These nanoparticles present good biocompatibility and higher longitudinal and transversal relaxivity values than commercial Gd3+ solutions, which significantly improves the sensitivity of in vivo magnetic resonance images. Full article
(This article belongs to the Special Issue Nanomaterials for Cancer Therapies)
Figures

Figure 1

Open AccessFeature PaperArticle DNA Sequencing by Hexagonal Boron Nitride Nanopore: A Computational Study
Nanomaterials 2016, 6(6), 111; doi:10.3390/nano6060111
Received: 2 May 2016 / Revised: 27 May 2016 / Accepted: 31 May 2016 / Published: 6 June 2016
Cited by 1 | PDF Full-text (2813 KB) | HTML Full-text | XML Full-text
Abstract
The single molecule detection associated with DNA sequencing has motivated intensive efforts to identify single DNA bases. However, little research has been reported utilizing single-layer hexagonal boron nitride (hBN) for DNA sequencing. Here we employ molecular dynamics simulations to explore pathways for single-strand
[...] Read more.
The single molecule detection associated with DNA sequencing has motivated intensive efforts to identify single DNA bases. However, little research has been reported utilizing single-layer hexagonal boron nitride (hBN) for DNA sequencing. Here we employ molecular dynamics simulations to explore pathways for single-strand DNA (ssDNA) sequencing by nanopore on the hBN sheet. We first investigate the adhesive strength between nucleobases and the hBN sheet, which provides the foundation for the hBN-base interaction and nanopore sequencing mechanism. Simulation results show that the purine base has a more remarkable energy profile and affinity than the pyrimidine base on the hBN sheet. The threading of ssDNA through the hBN nanopore can be clearly identified due to their different energy profiles and conformations with circular nanopores on the hBN sheet. The sequencing process is orientation dependent when the shape of the hBN nanopore deviates from the circle. Our results open up a promising avenue to explore the capability of DNA sequencing by hBN nanopore. Full article
(This article belongs to the Special Issue Computational Modeling and Simulations of Carbon Nanomaterials)
Figures

Figure 1

Open AccessArticle A Flexible 360-Degree Thermal Sound Source Based on Laser Induced Graphene
Nanomaterials 2016, 6(6), 112; doi:10.3390/nano6060112
Received: 26 April 2016 / Revised: 16 May 2016 / Accepted: 30 May 2016 / Published: 7 June 2016
Cited by 2 | PDF Full-text (2603 KB) | HTML Full-text | XML Full-text
Abstract
A flexible sound source is essential in a whole flexible system. It’s hard to integrate a conventional sound source based on a piezoelectric part into a whole flexible system. Moreover, the sound pressure from the back side of a sound source is usually
[...] Read more.
A flexible sound source is essential in a whole flexible system. It’s hard to integrate a conventional sound source based on a piezoelectric part into a whole flexible system. Moreover, the sound pressure from the back side of a sound source is usually weaker than that from the front side. With the help of direct laser writing (DLW) technology, the fabrication of a flexible 360-degree thermal sound source becomes possible. A 650-nm low-power laser was used to reduce the graphene oxide (GO). The stripped laser induced graphene thermal sound source was then attached to the surface of a cylindrical bottle so that it could emit sound in a 360-degree direction. The sound pressure level and directivity of the sound source were tested, and the results were in good agreement with the theoretical results. Because of its 360-degree sound field, high flexibility, high efficiency, low cost, and good reliability, the 360-degree thermal acoustic sound source will be widely applied in consumer electronics, multi-media systems, and ultrasonic detection and imaging. Full article
Figures

Figure 1

Open AccessArticle Targeting and Photodynamic Killing of Cancer Cell by Nitrogen-Doped Titanium Dioxide Coupled with Folic Acid
Nanomaterials 2016, 6(6), 113; doi:10.3390/nano6060113
Received: 27 April 2016 / Revised: 30 May 2016 / Accepted: 1 June 2016 / Published: 14 June 2016
Cited by 5 | PDF Full-text (1578 KB) | HTML Full-text | XML Full-text
Abstract
Titanium dioxide (TiO2) has attracted wide attention as a potential photosensitizer (PS) in photodynamic therapy (PDT). However, bare TiO2 can only be excited by ultraviolet illumination, and it lacks specific targeting ligands, which largely impede its application. In our study,
[...] Read more.
Titanium dioxide (TiO2) has attracted wide attention as a potential photosensitizer (PS) in photodynamic therapy (PDT). However, bare TiO2 can only be excited by ultraviolet illumination, and it lacks specific targeting ligands, which largely impede its application. In our study, we produced nitrogen-doped TiO2 and linked it with an effective cancer cell targeting agent, folic acid (FA), to obtain N-TiO2-FA nanoconjugates. Characterization of N-TiO2-FA included Zeta potential, absorption spectra and thermogravimetric analysis. The results showed that N-TiO2-FA was successfully produced and it possessed better dispersibility in aqueous solution than unmodified TiO2. The N-TiO2-FA was incubated with human nasopharyngeal carcinoma (KB) and human pulmonary adenocarcinoma (A549) cells. The KB cells that overexpress folate receptors (FR) on cell membranes were used as FR-positive cancer cells, while A549 cells were used as FR-negative cells. Laser scanning confocal microscopy results showed that KB cells had a higher uptake efficiency of N-TiO2-FA, which was about twice that of A549 cells. Finally, N-TiO2-FA is of no cytotoxicity, and has a better photokilling effect on KB cells under visible light irradiation. In conclusion, N-TiO2-FA can be as high-value as a PS in cancer targeting PDT. Full article
(This article belongs to the Special Issue Nanomaterials for Cancer Therapies)
Figures

Open AccessFeature PaperArticle Correlation between CdSe QD Synthesis, Post-Synthetic Treatment, and BHJ Hybrid Solar Cell Performance
Nanomaterials 2016, 6(6), 115; doi:10.3390/nano6060115
Received: 20 April 2016 / Revised: 1 June 2016 / Accepted: 6 June 2016 / Published: 14 June 2016
Cited by 2 | PDF Full-text (3935 KB) | HTML Full-text | XML Full-text
Abstract
In this publication we show that the procedure to synthesize nanocrystals and the post-synthetic nanocrystal ligand sphere treatment have a great influence not only on the immediate performance of hybrid bulk heterojunction solar cells, but also on their thermal, long-term, and air stability.
[...] Read more.
In this publication we show that the procedure to synthesize nanocrystals and the post-synthetic nanocrystal ligand sphere treatment have a great influence not only on the immediate performance of hybrid bulk heterojunction solar cells, but also on their thermal, long-term, and air stability. We herein demonstrate this for the particular case of spherical CdSe nanocrystals, post-synthetically treated with a hexanoic acid based treatment. We observe an influence from the duration of this post-synthetic treatment on the nanocrystal ligand sphere size, and also on the solar cell performance. By tuning the post-synthetic treatment to a certain degree, optimal device performance can be achieved. Moreover, we show how to effectively adapt the post-synthetic nanocrystal treatment protocol to different nanocrystal synthesis batches, hence increasing the reproducibility of hybrid nanocrystal:polymer bulk-heterojunction solar cells, which usually suffers due to the fluctuations in nanocrystal quality of different synthesis batches and synthesis procedures. Full article
(This article belongs to the Special Issue Nanostructured Solar Cells) Printed Edition available
Figures

Figure 1

Open AccessFeature PaperArticle Human Serum Albumin Nanoparticles for Use in Cancer Drug Delivery: Process Optimization and In Vitro Characterization
Nanomaterials 2016, 6(6), 116; doi:10.3390/nano6060116
Received: 12 April 2016 / Revised: 31 May 2016 / Accepted: 3 June 2016 / Published: 15 June 2016
Cited by 3 | PDF Full-text (3898 KB) | HTML Full-text | XML Full-text
Abstract
Human serum albumin nanoparticles (HSA-NPs) are widely-used drug delivery systems with applications in various diseases, like cancer. For intravenous administration of HSA-NPs, the particle size, surface charge, drug loading and in vitro release kinetics are important parameters for consideration. This study focuses on
[...] Read more.
Human serum albumin nanoparticles (HSA-NPs) are widely-used drug delivery systems with applications in various diseases, like cancer. For intravenous administration of HSA-NPs, the particle size, surface charge, drug loading and in vitro release kinetics are important parameters for consideration. This study focuses on the development of stable HSA-NPs containing the anti-cancer drug paclitaxel (PTX) via the emulsion-solvent evaporation method using a high-pressure homogenizer. The key parameters for the preparation of PTX-HSA-NPs are: the starting concentrations of HSA, PTX and the organic solvent, including the homogenization pressure and its number cycles, were optimized. Results indicate a size of 143.4 ± 0.7 nm and 170.2 ± 1.4 nm with a surface charge of −5.6 ± 0.8 mV and −17.4 ± 0.5 mV for HSA-NPs and PTX-HSA-NPs (0.5 mg/mL of PTX), respectively. The yield of the PTX-HSA-NPs was ~93% with an encapsulation efficiency of ~82%. To investigate the safety and effectiveness of the PTX-HSA-NPs, an in vitro drug release and cytotoxicity assay was performed on human breast cancer cell line (MCF-7). The PTX-HSA-NPs showed dose-dependent toxicity on cells of 52%, 39.3% and 22.6% with increasing concentrations of PTX at 8, 20.2 and 31.4 μg/mL, respectively. In summary, all parameters involved in HSA-NPs’ preparation, its anticancer efficacy and scale-up are outlined in this research article. Full article
(This article belongs to the Special Issue Nanomaterials for Cancer Therapies)
Figures

Figure 1

Open AccessCommunication Ag Nanoparticle–Functionalized Open-Ended Freestanding TiO2 Nanotube Arrays with a Scattering Layer for Improved Energy Conversion Efficiency in Dye-Sensitized Solar Cells
Nanomaterials 2016, 6(6), 117; doi:10.3390/nano6060117
Received: 30 March 2016 / Revised: 1 June 2016 / Accepted: 6 June 2016 / Published: 15 June 2016
Cited by 7 | PDF Full-text (2202 KB) | HTML Full-text | XML Full-text
Abstract
Dye-sensitized solar cells (DSSCs) were fabricated using open-ended freestanding TiO2 nanotube arrays functionalized with Ag nanoparticles (NPs) in the channel to create a plasmonic effect, and then coated with large TiO2 NPs to create a scattering effect in order to improve
[...] Read more.
Dye-sensitized solar cells (DSSCs) were fabricated using open-ended freestanding TiO2 nanotube arrays functionalized with Ag nanoparticles (NPs) in the channel to create a plasmonic effect, and then coated with large TiO2 NPs to create a scattering effect in order to improve energy conversion efficiency. Compared to closed-ended freestanding TiO2 nanotube array–based DSSCs without Ag or large TiO2 NPs, the energy conversion efficiency of closed-ended DSSCs improved by 9.21% (actual efficiency, from 5.86% to 6.40%) with Ag NPs, 6.48% (actual efficiency, from 5.86% to 6.24%) with TiO2 NPs, and 14.50% (actual efficiency, from 5.86% to 6.71%) with both Ag NPs and TiO2 NPs. By introducing Ag NPs and/or large TiO2 NPs to open-ended freestanding TiO2 nanotube array–based DSSCs, the energy conversion efficiency was improved by 9.15% (actual efficiency, from 6.12% to 6.68%) with Ag NPs and 8.17% (actual efficiency, from 6.12% to 6.62%) with TiO2 NPs, and by 15.20% (actual efficiency, from 6.12% to 7.05%) with both Ag NPs and TiO2 NPs. Moreover, compared to closed-ended freestanding TiO2 nanotube arrays, the energy conversion efficiency of open-ended freestanding TiO2 nanotube arrays increased from 6.71% to 7.05%. We demonstrate that each component—Ag NPs, TiO2 NPs, and open-ended freestanding TiO2 nanotube arrays—enhanced the energy conversion efficiency, and the use of a combination of all components in DSSCs resulted in the highest energy conversion efficiency. Full article
(This article belongs to the Special Issue Nanostructured Solar Cells) Printed Edition available
Figures

Figure 1

Open AccessArticle Quaternized Carboxymethyl Chitosan-Based Silver Nanoparticles Hybrid: Microwave-Assisted Synthesis, Characterization and Antibacterial Activity
Nanomaterials 2016, 6(6), 118; doi:10.3390/nano6060118
Received: 3 May 2016 / Revised: 24 May 2016 / Accepted: 1 June 2016 / Published: 17 June 2016
Cited by 2 | PDF Full-text (5271 KB) | HTML Full-text | XML Full-text
Abstract
A facile, efficient, and eco-friendly approach for the preparation of uniform silver nanoparticles (Ag NPs) was developed. The synthesis was conducted in an aqueous medium exposed to microwave irradiation for 8 min, using laboratory-prepared, water-soluble quaternized carboxymethyl chitosan (QCMC) as a chemical reducer
[...] Read more.
A facile, efficient, and eco-friendly approach for the preparation of uniform silver nanoparticles (Ag NPs) was developed. The synthesis was conducted in an aqueous medium exposed to microwave irradiation for 8 min, using laboratory-prepared, water-soluble quaternized carboxymethyl chitosan (QCMC) as a chemical reducer and stabilizer and silver nitrate as the silver source. The structure of the prepared QCMC was characterized using Fourier transform infrared (FT-IR) and 1H nuclear magnetic resonance (NMR). The formation, size distribution, and dispersion of the Ag NPs in the QCMC matrix were determined using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible (UV-Vis), transmission electron microscopy (TEM), and field emission scanning electron microscope (FESEM) analysis, and the thermal stability and antibacterial properties of the synthesized QCMC-based Ag NPs composite (QCMC-Ag) were also explored. The results revealed that (1) QCMC was successfully prepared by grafting quaternary ammonium groups onto carboxymethyl chitosan (CMC) chains under microwave irradiation in water for 90 min and this substitution appeared to have occurred at -NH2 sites on C2 position of the pyranoid ring; (2) uniform and stable spherical Ag NPs could be synthesized when QCMC was used as the reducing and stabilizing agent; (3) Ag NPs were well dispersed in the QCMC matrix with a narrow size distribiution in the range of 17–31 nm without aggregation; and (4) due to the presence of Ag NPs, the thermal stability and antibacterial activity of QCMC-Ag were dramatically improved relative to QCMC. Full article
Figures

Figure 1

Open AccessArticle Hydrothermal Fabrication of Silver Nanowires-Silver Nanoparticles-Graphene Nanosheets Composites in Enhancing Electrical Conductive Performance of Electrically Conductive Adhesives
Nanomaterials 2016, 6(6), 119; doi:10.3390/nano6060119
Received: 1 April 2016 / Revised: 1 June 2016 / Accepted: 7 June 2016 / Published: 21 June 2016
Cited by 2 | PDF Full-text (4100 KB) | HTML Full-text | XML Full-text
Abstract
Silver nanowires-silver nanoparticles-graphene nanosheets (AgNWs-AgNPs-GN) hybrid nanomaterials were fabricated through a hydrothermal method by using glucose as a green reducing agent. The charge carriers of AgNWs-AgNPs-GN passed through defect regions in the GNs rapidly with the aid of the AgNW and AgNP building
[...] Read more.
Silver nanowires-silver nanoparticles-graphene nanosheets (AgNWs-AgNPs-GN) hybrid nanomaterials were fabricated through a hydrothermal method by using glucose as a green reducing agent. The charge carriers of AgNWs-AgNPs-GN passed through defect regions in the GNs rapidly with the aid of the AgNW and AgNP building blocks, leading to high electrical conductivity of electrically conductive adhesives (ECA) filled with AgNWs-AgNPs-GN. The morphologies of synthesized AgNWs-AgNPs-GN hybrid nanomaterials were characterized by field emission scanning electron microscope (FESEM), and high resolution transmission electron microscopy (HRTEM). X-ray diffraction (XRD) and laser confocal micro-Raman spectroscopy were used to investigate the structure of AgNWs-AgNPs-GN. The resistance of cured ECAs was investigated by the four-probe method. The results indicated AgNWs-AgNPs-GN hybrid nanomaterials exhibited excellent electrical properties for decreasing the resistivity of electrically conductive adhesives (ECA). The resistivity of ECA was 3.01 × 10−4 Ω·cm when the content of the AgNWs-AgNPs-GN hybrid nanomaterial was 0.8 wt %. Full article
Figures

Review

Jump to: Editorial, Research, Other

Open AccessFeature PaperReview Selective Plasma Etching of Polymeric Substrates for Advanced Applications
Nanomaterials 2016, 6(6), 108; doi:10.3390/nano6060108
Received: 2 February 2016 / Revised: 28 May 2016 / Accepted: 30 May 2016 / Published: 7 June 2016
Cited by 4 | PDF Full-text (3899 KB) | HTML Full-text | XML Full-text
Abstract
In today’s nanoworld, there is a strong need to manipulate and process materials on an atom-by-atom scale with new tools such as reactive plasma, which in some states enables high selectivity of interaction between plasma species and materials. These interactions first involve preferential
[...] Read more.
In today’s nanoworld, there is a strong need to manipulate and process materials on an atom-by-atom scale with new tools such as reactive plasma, which in some states enables high selectivity of interaction between plasma species and materials. These interactions first involve preferential interactions with precise bonds in materials and later cause etching. This typically occurs based on material stability, which leads to preferential etching of one material over other. This process is especially interesting for polymeric substrates with increasing complexity and a “zoo” of bonds, which are used in numerous applications. In this comprehensive summary, we encompass the complete selective etching of polymers and polymer matrix micro-/nanocomposites with plasma and unravel the mechanisms behind the scenes, which ultimately leads to the enhancement of surface properties and device performance. Full article
(This article belongs to the Special Issue Plasma Nanoengineering and Nanofabrication)
Figures

Figure 1

Open AccessFeature PaperReview Complex-Morphology Metal-Based Nanostructures: Fabrication, Characterization, and Applications
Nanomaterials 2016, 6(6), 110; doi:10.3390/nano6060110
Received: 21 April 2016 / Revised: 18 May 2016 / Accepted: 21 May 2016 / Published: 6 June 2016
Cited by 3 | PDF Full-text (9511 KB) | HTML Full-text | XML Full-text
Abstract
Due to their peculiar qualities, metal-based nanostructures have been extensively used in applications such as catalysis, electronics, photography, and information storage, among others. New applications for metals in areas such as photonics, sensing, imaging, and medicine are also being developed. Significantly, most of
[...] Read more.
Due to their peculiar qualities, metal-based nanostructures have been extensively used in applications such as catalysis, electronics, photography, and information storage, among others. New applications for metals in areas such as photonics, sensing, imaging, and medicine are also being developed. Significantly, most of these applications require the use of metals in the form of nanostructures with specific controlled properties. The properties of nanoscale metals are determined by a set of physical parameters that include size, shape, composition, and structure. In recent years, many research fields have focused on the synthesis of nanoscale-sized metallic materials with complex shape and composition in order to optimize the optical and electrical response of devices containing metallic nanostructures. The present paper aims to overview the most recent results—in terms of fabrication methodologies, characterization of the physico-chemical properties and applications—of complex-morphology metal-based nanostructures. The paper strongly focuses on the correlation between the complex morphology and the structures’ properties, showing how the morphological complexity (and its nanoscale control) can often give access to a wide range of innovative properties exploitable for innovative functional device production. We begin with an overview of the basic concepts on the correlation between structural and optical parameters of nanoscale metallic materials with complex shape and composition, and the possible solutions offered by nanotechnology in a large range of applications (catalysis, electronics, photonics, sensing). The aim is to assess the state of the art, and then show the innovative contributions that can be proposed in this research field. We subsequently report on innovative, versatile and low-cost synthesis techniques, suitable for providing a good control on the size, surface density, composition and geometry of the metallic nanostructures. The main purpose of this study is the fabrication of functional nanoscale-sized materials, whose properties can be tailored (in a wide range) simply by controlling the structural characteristics. The modulation of the structural parameters is required to tune the plasmonic properties of the nanostructures for applications such as biosensors, opto-electronic or photovoltaic devices and surface-enhanced Raman scattering (SERS) substrates. The structural characterization of the obtained nanoscale materials is employed in order to define how the synthesis parameters affect the structural characteristics of the resulting metallic nanostructures. Then, macroscopic measurements are used to probe their electrical and optical properties. Phenomenological growth models are drafted to explain the processes involved in the growth and evolution of such composite systems. After the synthesis and characterization of the metallic nanostructures, we study the effects of the incorporation of the complex morphologies on the optical and electrical responses of each specific device. Full article
(This article belongs to the Special Issue Semiconductor Core/Shell Nanocrystals for Optoelectronic Applications)
Figures

Figure 1

Other

Jump to: Editorial, Research, Review

Open AccessErratum Erratum: Mustafa, R.; Luo, Y.; Wu, Y.; Guo, R.; Shi, X. Dendrimer-Functionalized Laponite® Nanodisks as a Platform for Anticancer Drug Delivery. Nanomaterials 2015, 5, 1716–1731
Nanomaterials 2016, 6(6), 114; doi:10.3390/nano6060114
Received: 13 June 2016 / Revised: 13 June 2016 / Accepted: 13 June 2016 / Published: 14 June 2016
PDF Full-text (146 KB) | HTML Full-text | XML Full-text
Abstract
It has been brought to our attention that Laponite® is a trademark of BYK Additives, however the trademark symbol is missing in [1].[...] Full article

Journal Contact

MDPI AG
Nanomaterials Editorial Office
St. Alban-Anlage 66, 4052 Basel, Switzerland
E-Mail: 
Tel. +41 61 683 77 34
Fax: +41 61 302 89 18
Editorial Board
Contact Details Submit to Nanomaterials Edit a special issue Review for Nanomaterials
logo
loading...
Back to Top