Nanoscience and Nanotechnology Letters
Nanoscience and Nanotechnology Letters (NNL) is a multidisciplinary peer-reviewed journal consolidating nanoscale research activities in all disciplines of science, engineering and medicine into a single and unique reference source. NNL provides the means for scientists, engineers, medical experts and technocrats to publish original short research articles as communications/letters of important new scientific and technological findings, encompassing the fundamental and applied research in all disciplines of the physical sciences, engineering and medicine.
Journal Impact: 1.07*
Journal impact history
|2016 Journal impact||Available summer 2017|
|2015 Journal impact||1.07|
|2014 Journal impact||1.38|
|2013 Journal impact||1.45|
|2012 Journal impact||0.89|
|2011 Journal impact||0.60|
|2010 Journal impact||0.42|
Journal impact over time
|Website||Nanoscience and Nanotechnology Letters|
Publications in this journal
- [Show abstract] [Hide abstract] ABSTRACT: Nano-porous layer on implant surface has been considered as the most advantageous and advisable factor for the bone ingrowth and to improve the overall stability of the implant. In the present research work, a biomimetic novel nanoporous layer was fabricated directly on the β-Ti implant using powder mixed electrical discharge machining (PMEDM). PMEDM produce microscale pits of size 70 µm and a biomimetic interconnected porous layer of size 200–500 nm was produced in these pits. The application of PMEDM not only imparted the nanoporous topography but also altered the surface chemistry favorable for bioactivity. The viability and mineralization of human osteoblast-like (MG-63) cells in a nano-porous surface produced by PMEDM was analyzed by the In-Vitro bioactivity analysis. The results confirmed that the nano-porous surface obtained by PMEDM facilitated the higher adhesion and growth of osteoblast-like cell (MG-63) when compared to non-porous specimen’s surface. At last finite element analysis (FEA) was performed to the estimate the tensile and shears strength of bone-implant interface of bone-Implant models containing PMEDM-attainable intersecting nano-porous layer. The results obtained by FEA of bone-Implant models suggested that the nano-porous surface produced by PMEDM produce exhibit higher bone/implant interface strengths as compared with models containing EDMed pores geometry and plane surface geometries (non-porous). In conclusion, the PMEDM treatment has potential to produce micro-pits of the intersecting porous layer which have a considerable effect on cell attachment, proliferation, bone ingrowth and enhances the bone-implant interface strength.
- [Show abstract] [Hide abstract] ABSTRACT: Herein, we report the successful synthesis of two types of Co3O4 nanostructures, i.e., urchin-shaped and nanoneedle bundles. The prepared nanomaterials were synthesized via facile hydrothermal and subsequent heat treatment process at 300 °C. The structure and morphologies of both prepared materials were thoroughly characterized using different analytical tools and finally, the prepared nanomaterials were used as electron mediators to fabricate high-sensitive hydrazine chemical sensors. The detailed sensing studies revealed that the fabricated sensors based on Co3O4 urchin-shaped and nanoneedle bundles exhibited high sensitivity and low-detection limit. The detailed sensing performances such as sensitivity, detection limit, and linear range for the fabricated hydrazine chemical sensors were comprehensively compared. The results exhibited that the Co3O4 urchin-shaped structures based hydrazine sensor showed wider linear range (5–610 μM) and lower detection limit (1.29 μM), however, the Co3O4 nanoneedle bundles based hydrazine sensor exhibited higher sensitivity (95.25 μA·mM–1).
- [Show abstract] [Hide abstract] ABSTRACT: We elongated silver (Ag) and molybdenum (Mo) nanocontacts under an applied bias voltage inside a transmission electron microscope (TEM). The elongation process was observed in situ by lattice imaging. Single-atom-width wires (SWs) of both metals formed over certain bias voltage ranges. We investigated the probability of SW formation over a range of bias voltages. The Ag SW formation probability was lower at high bias voltages. No Ag SWs were formed at voltages higher than 20 mV. Conversely, the formation probability of Mo SWs showed no dependence on bias voltage in the range 0–150 mV.
- [Show abstract] [Hide abstract] ABSTRACT: In order to minimize the side effects and improve the therapeutic efficiency of doxorubicin hydrochloride (DOX), targeted drug delivery and the controlled drug release techniques at the tumor sites are necessary. In this work, polyhedral Fe3O4 hollow spheres were synthesized by using hexamethylenetetramine (HMT) as structure directing agent and modified by using 3-mercaptopropyltrimethoxysilane (MPS). The resulting products (Fe3O4-MPS) possess high magnetism at room temperature, large cavity and high water solubility. Experimental results indicate that the maximal DOX-loading efficiency of Fe3O4-MPS was approximately 88%, and the cumulative releasing efficiency of DOX at pH 5.0 was about 93% over 24 hours. Because of a satisfactory magnetic response and large surface area, DOX-loaded Fe3O4-MPS spheres (Fe3O4-MPS-DOX triads) could quickly reach to the disease tissues and release drug controlled. The lower releasing efficiency of DOX at pH 7.4 (about 8%) could alleviate systemic toxicity of DOX. Hence, Fe3O4-MPS-DOX triads will be a promising drug delivery carrier for targeted cancer therapy.
- [Show abstract] [Hide abstract] ABSTRACT: A series of novel thermal- and pH-sensitive polyurethane (PU) hydrogels with different transition temperatures were successfully synthesized via a three-step polymerization using polyethylene glycol (PEG), 4,4'-diphenylmethane diisocyanate (MDI), dimethylol propionic acid (DMPA) and trimethylolpropane (TMP). Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were employed to characterize the basic properties of the PU hydrogels. The swelling tests were simultaneously used to measure the thermal- and pH-sensitive properties of the PU hydrogels. FTIR analysis demonstrated that the PEG (the temperature-sensitive component) and –COOH groups (the pH-sensitive component) were successfully introduced into the PU molecule chains. SEM study indicated that the PU hydrogels possessed a honeycomb structure, while the DSC and XRD analysis revealed that the PEG crystallization in the PU hydrogels were still retained and the onset of transition temperature for the PU hydrogels appeared at 15.8 °C, 23.6 °C, 33.4 °C, 36.5 °C and 38.3 °C, respectively. In addition, the swelling tests showed the thermal- and pH-sensitive properties for all the PU hydrogels. Concretely, when temperature was increased from 15 °C to 25 °C, the equilibrium swelling ratio (ESR) for the hydrogels 1 and 2 showed an obvious decrease and the other three PU hydrogels showed significant decrease when the temperature was increased from 35 °C to 45 °C. Moreover, the ESR increased sharply when the pH value was increased from 4.0 to 7.0. With their thermaland pH-sensitive properties, the synthesized PU hydrogels have potential for use in many fields, such as biomaterials, molecular imprinting materials, adsorbing materials and so on.
- [Show abstract] [Hide abstract] ABSTRACT: In this paper, the electrical conductivity of SiO2 nanofluids using pure water (H2O) as the base fluid is investigated. The two-step method was used to prepare the SiO2–H2O nanofluids. The variations in electrical conductivity of SiO2–H2O nanofluids as function of mass concentration of 0.1–1.0% and temperature of 25.2–64.3 are present. Experimental results show that the correlation of electrical conductivity of SiO2–H2O nanofluids and mass concentration, temperature is nearly linear. However, the effect of temperature on electrical conductivity is much less than that of mass concentration. In order to evaluate the enhancement performance of SiO2–H2O nanofluids, the relative electrical conductivity is introduced and studied explicitly. The relative electrical conductivity means the ratio between the electrical conductivity of SiO2–H2O nanofluids to pure water. It is found that the relative electrical conductivity increases with the increase of mass fraction and decreases with the increase of temperature. Finally, an empirical correlation is built to predict the electrical conductivity with varied combination of mass fraction and temperature.
- [Show abstract] [Hide abstract] ABSTRACT: Systemically administered recombinant t-PA thrombolytic therapy has become a standard clinical treatment for acute myocardial infarction. However, its significant complications remain. We in this study established an in-stent thrombosis model with intimal hyperplasia by de-endothelialization of rabbit iliac artery, followed by bare-mental stenting (BMS) implantation. We then constructed a highly expressive t-PA gene plasmid packed with albumin nanoparticles which were crosslinked to albumin ultrasound micro bubbles. The gene vector was then transferred into the implanted arteries under therapeutic ultrasound aid (1 MHz, 1.5 w/cm2, 6 mins, intravenously) after stenting intervention. The expression of t-PA in the implanted arteries and tissues around them was detected by multiclonal antibodies to t-PA, using the indirect immunohistochemical method. Venous blood t-PA and D-dimer contents were tested before weeks 1, 2, 4 and 8 after the operation. The effects of the constructed t-PA gene plasmid on the in-stent thrombosis and vascular intimal hyperplasia were observed by routine pathological examination, morphometry for intimal thickness and area, and immuno-histochemical stains using the monoclonal antibody to PCNA for estimating the intimal SMC proliferation. The effective expression of the t-PA in the implanted arteries and their surrounding tissues in the ultrasonic field was obtained, followed by persistent rising of the blood t-PA and D-dimer in weeks 1, 2, 4 and 8 after the targeting transfection. The In-stent thrombosis and intimal hyperplasia were successfully restrained. The transfection of the albumin nano-t-PA gene into the implanted arteries under the ultrasound microbubbles was also successfully performed. The transfected nano t-PA gene could prevent the in-stent thrombosis and reduce intimal hyperplasia under the implanted stents.
- [Show abstract] [Hide abstract] ABSTRACT: We in this paper presented a single-base resolution method for discrimination of single base pair differences within DNA duplexes containing A-T matched base pairs and A-C mismatched base pairs using α-hemolysin (α-HL) protein nanopore embedded in a lipid bilayer. A 17-mer probe respectively annealed to two 57-mer target ssDNA which had poly(dT)20 tails on both 5' and 3' ends, forming single base-pair differentiating DNA duplexes containing the matched A-T base pairs and A-C mismatched base pairs which were then voltage-driven captured and stacked into the α-HL constriction zone under a biased potential. After a long unzipping process, the longer stranded and probe DNA was successively separated and translocated through the α-HL channel, then generating a characteristic signal. Ion channel recordings were used to detect and compare the unzipping process. The duplex structures exhibited different unzipping time duration under applied voltage by firstly threading either the 3' or 5' overhangs into the α-hemolysin channel that permitted easy discrimination between the completely matched and single-mismatched base pairs. The simple biosensing strategy will open up a variety of applications on SNP sites detection, diseases classification, medical screening and diagnosis.
- [Show abstract] [Hide abstract] ABSTRACT: PCR detection of drowning related algal DNA from organs of drowning victims has attracted huge interest in forensic research. Magnetic nanoparticles (MNPs) have been regarded as an efficient tool for automatic DNA extraction; however, whether the algal DNA can be efficiently extracted has remained doubtful. In this study, a multiplex PCR-Capillary electrophoresis (MPCE) system was established by using two popular algal primers for SSU and UPA genes respectively. Three types of commercially available MNPs were then used for DNA extraction from the tissues of 20 cadavers found in the water. The MNPs were evaluated by the MPCE system and results showed that the MNPs (XiaoMai Biotech) significantly increased the positive detection rate (80%) (P < 0.05) compared to others. The MNPs also had better result than the Microwave Digestion-Vacuum Filtration-Automated Scanning Electron Microscopy (MD-VF-Auto SEM) test method (75%, P > 0.05).
- [Show abstract] [Hide abstract] ABSTRACT: Herein, we report the synthesis and characterization of Bi2WO6 spheres composed of fluffy thin nanosheets prepared by simple and facile hydrothermal process. The synthesized Bi2WO6 spheres were characterized in detail to examine the morphological, structural, optical and photocatalytic properties. The detailed morphological characterizations, done by scanning electron microscopy, revealed that the synthesized Bi2WO6 spheres are made by the accumulation of several Bi2WO6 thin nanosheets. The nanosheets are arranged in such a special manner that they made specific sphere-shaped morphologies. The detailed structural properties confirmed that the prepared Bi2WO6 spheres possess well-crystallinity and orthorhombic crystal structure. The detailed UV-DRS and room-temperature photoluminescence (PL) studies confirmed good optical properties for the synthesized Bi2WO6 spheres. Finally, the photocatalytic degradation of a fluoroquinolone antibiotic, ofloxacin, was studied under visible light irradiation in aqueous phase using Bi2WO6 spheres as catalyst. By detailed photocatalytic experiments, it was found that ∼73% ofloxacin was degraded in 120 minutes in presence of Bi2WO6 spheres under visible light irradiation. Interestingly, the photocatalytic kinetic studies confirmed that the photocatalytic process followed the pseudo first order reaction kinetics with rate constant (k) of 0.00926 min–1. The observed results demonstrate that Bi2WO6 nanomaterials are potential scaffold for the photocatalytic degradation of harmful antibiotics under visible-light irradiation.
- [Show abstract] [Hide abstract] ABSTRACT: With the development of the transverse tunneling current theory, electrode-embedded nanopore is considered as one of the most promising devices for label-free DNA sequencing. Though there have been a few approaches to fabricate transverse electrode-embedded nanopores, the method universality and nanogap control are still formidable tasks of fabricating a nano-scale electrodenanopore sensor. In this work, a cross-scale approach of fabricating nano-electrodes was proposed, and a 10 nm-width nano-electrode was obtained from 5 μm-width aurum (Au) line. Compared with traditional methods, only electron microscopy was involved in this process, which was a simple and effective method to fabricate electrode-embedded nanopores. Furthermore, the gap of nanoelectrodes was controllable as the nano-electrode was cut off by drilling nanopore. The feasibility of the method was investigated by practice. This article demonstrated a novel approach to fabricate transverse electrode-embedded nanopore which showed great application potential in fabricating nano-electrodes with gap smaller than 2 nm.
- [Show abstract] [Hide abstract] ABSTRACT: ZnO nanoparticles, as a kind of multifunctional inorganic nanomaterial, are reported with a broadspectrum effective antimicrobial activity. This study was aimed at determining the antimycotic ability of home-made ZnO nanoparticles. Three methods including emulsion, micro-emulsion and direct precipitation were applied to synthesize ZnO nanoparticles. Penicillium and Mucor were selected as experimental subjects to determine the antimycotic ability of ZnO nanoparticles. In addition, Myxomycete was selected as a reference. Hexagonal wurtzite ZnO nanoparticles were obtained in each method. Emulsion method yielded monodispersed spherical nanoparticles with size distribution in range between 60 to 250 nm. Direct precipitation method yielded irregular polygonal-flake nanoparticles with average thickness of 50±2 nm and width ranging from 100 to 800 nm. ZnO nanoparticles prepared by micro-emulsion method have a uniform shape and flower-like morphology formed by uniform wafers embedded in each other, and also have a narrow size distribution with 20 nm in average thickness and 600 nm in average diameter. Antimycotic experiment showed that the as-prepared ZnO nanoparticles, especially by micro-emulsion method, could change the morphology of mycetes, and inhibit the growth and the reproduction of these three kinds of fungi as well. It was also indicated that ZnO nanoparticles prepared by micro-emulsion method could find wide application in antimicrobial scope.
- [Show abstract] [Hide abstract] ABSTRACT: In this study, photoanodes using well-aligned ZnO nanorods on transparent conductive gallium doped ZnO film were investigated for application in dye-sensitized solar cell. In order to choose the most suitable conductive substrate for photoanodes, thickness effects on electrical, optical and structural properties of gallium doped ZnO films were investigated. The lowest resistivity (3.96 × 10 –4 Ω · cm) and the highest hall mobility (14.12 cm2/(V · s)) were obtained from 300 nm-thick gallium doped ZnO film. ZnO nanorods were fabricated on the obtained gallium doped ZnO films by recrystallization of reduced ZnO film with the multi-annealing method. It was found that the vertical alignment of ZnO nanorods was dependent on the growth orientation of ZnO film on GZO film. A high transmittance of 70% was obtained from ZnO nanorods on 300 nm-thick gallium doped ZnO film. The demonstrated dye-sensitized solar cell showed an overall conversion efficiency of 3.19% with a fill factor of 0.62.
- [Show abstract] [Hide abstract] ABSTRACT: Sidewall angle (SWA) of an absorber stack in extreme ultraviolet lithography mask is considered to be 90° ideally, however, it is difficult to obtain 90° SWA because absorber profile is changed by complicated etching process conditions. As the imaging performance of the mask can be varied with this SWA of the absorber stack, more complicated optical proximity correction is required to compensate for the variation of imaging performance. In this study, phase shift mask (PSM) is suggested to reduce the variation of imaging performance due to SWA change by modifying mask material and structure. Variations of imaging performance and lithography process margin depending on SWA were evaluated through aerial image and developed resist simulations to confirm the advantages of PSM over the binary intensity mask (BIM). The results showed that the variations of normalized image log slope and critical dimension bias depending on SWA were reduced by using PSM compared to BIM. Process margin for exposure dose and focus was also improved with PSM.
- [Show abstract] [Hide abstract] ABSTRACT: By means of molecular dynamics (MD) simulations at atomic scale, atom movements and packed structures are observed by condensing two liquid copper clusters respectively containing 58 and 59 atoms within the framework of the embedded-atom method (EAM). In this work we offer structural characterizations of the above simulated systems, and local structure changes are demonstrated by pair analysis according to their local environments. Concerning lowering the quenching temperature, the simulation results for the two clusters reveal how the atom movements can cause strong differences in structural changes by identifying internal energy, and pair analysis as well as atomic packing. In high quenching temperature regimes, the atoms in both of the two clusters move continuously, and they are packed disorderly. As the freezing temperature is decreased, the atom movements present different behaviors. For the Cu58 cluster, the ordered packing fraction is apparently lower than that for the Cu59 cluster, and the atom packing cannot present the ordered configuration. For the Cu59 cluster, the whole cluster can present the icosahedral (Ih) configuration at 300 K, though some atoms interchange their positions in this cluster. The simulations show sensitivities of the structural changes to the two small size clusters with adding or removing one atom.
- [Show abstract] [Hide abstract] ABSTRACT: Back channel etch type copper/molybdenum tantalum/indium gallium zinc oxide thin film transistors (TFTs) are fabricated using only wet patterning in phosphoric acid based copper etchant. Phosphoric acid based wet etchant for IGZO thin films with copper metallization is developed. Compared to pure molybdenum S/D electrodes, MoTa alloy electrodes show better TFT performance both in terms of mobility and on current. This might be attributed to the reduced elastic strain energy resulting from the reduction in the biaxial elastic modulus of the MoTa film rather than the pure Mo film. The reduction in the elastic strain energy in the underlying IGZO film might reduce the trap densities in the film, resulting in the enhancement of the electron mobility of the film. The effects of the Tantalum percentage in the alloy on the electrical properties of back channel etch type Cu/Mo Ta/IGZO oxide TFTs are investigated.
- [Show abstract] [Hide abstract] ABSTRACT: We investigated the impact of the transmittance of EUV pellicles on imaging performance using coherent scattering microscopy (CSM). Although the pellicle has no effect on the optical path of diffracted light, it deteriorates the imaging performance owing to EUV photon loss. The results showed that the line critical dimension (CD) increased by 20.7% and that the normalized image log slope (NILS) decreased by 7.4% upon using a pellicle with 80% transmittance. Since the local transmittance variation due to pellicle non-uniformity or contamination can cause local CD variation, it is important to ensure uniform transmittance throughout the active pellicle area.
- [Show abstract] [Hide abstract] ABSTRACT: In this study, molecular dynamics simulations were performed to study the  compression deformation of magnesium nanopillars with square cross-sections at various temperatures. Singlecrystal magnesium nanopillars with the side-length of 10–30 nm were examined via employing embedded atom potential. Simulation results showed a strong temperature dependence on the mechanism for initial yielding as compared to that of plastic flow. The initial yielding was caused by the nucleation of 〈c + a〉 first-order pyramidal (π1) slip at 10–250 K, in contrast to deformation twinning at 300–500 K. The governing mechanism for plastic flow over the temperature range from 10 to 500 K was the multiplication and interaction of the 〈c + a〉 slip and basal slip.
- [Show abstract] [Hide abstract] ABSTRACT: Ag nanoparticles functionalized carbon nanospheres (AgNPs/CNS) were facilely synthesized using in-situ reduction method. The AgNPs/CNS nanocomposites were fully characterized with transmission electron microscope, scanning electron microscope, X-ray diffraction, and energy dispersive spectroscopy. Then, AgNPs/CNS was coated onto glassy carbon electrode surface and used as an electrochemical interface to immobilize hemoglobin to fabricate a novel biosensor. Direct electrochemistry of hemoglobin on the interface based on AgNPs/CNS was investigated by cyclic voltammetry. The experimental results demonstrated that AgNPs/CNS nanocomposites could well maintain the activity of hemoglobin and greatly improve its direct electrochemical behavior. In 0.1 mol L–1 phosphate buffer solution at the pH value of 7.0, hemoglobin, immobilized on the AgNPs/CNS surface, exhibits a pair of nearly reversible redox peaks. The biosensor shows good catalytic property towards the reduction of H2O2. A good linear relationship between the amperometric current response and H2O2 concentration in the range of 2.0 × 10 –6∼1.0 × 10–3 mol L–1 was obtained with a detection limit of 1.0 × 10–7 mol L–1 (S/N = 3). The developed AgNPs/CNS interface offers a promising platform for the further study on the biosensor fabrication.
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