Lipid droplets (LDs) are crucial biological organelles connected with metabolic pathways in biological systems and diseases. To monitor the locations and accumulation of LDs in lipid-related diseases, the development of a visualization tool for LDs has gained importance. In particular, LD visualization using fluorescent probes has gained attention.
View Article and Find Full Text PDFTogether with neuronal loss, the existence of insoluble inclusions of alpha-synuclein (α-syn) in the brain is widely accepted as a hallmark of synucleinopathies including Parkinson's disease (PD), multiple system atrophy, and dementia with Lewy body. Because the α-syn aggregates are deeply involved in the pathogenesis, there have been many attempts to demonstrate the mechanism of the aggregation and its potential causative factors including post-translational modifications (PTMs). Although no concrete conclusions have been made based on the previous study results, growing evidence suggests that modifications such as phosphorylation and ubiquitination can alter α-syn characteristics to have certain effects on the aggregation process in PD; either facilitating or inhibiting fibrillization.
View Article and Find Full Text PDFWe present a holey titanium dioxide (TiO2) film combined with a periodically aligned ZnO nanorod layer (ZNL) for maximum light utilization in dye-sensitized solar cells (DSCs). Both the holey TiO2 film and the ZNL were simultaneously fabricated by imprint technique with a mold having vertically aligned ZnO nanorod (NR) array, which was transferred to the TiO2 film after imprinting. The orientation of the transferred ZNL such as laid, tilted, and standing ZnO NRs was dependent on the pitch and height of the ZnO NRs of the mold.
View Article and Find Full Text PDFWe present nanoslit confined DNA conformations at very low ionic strengths and a theory to explain most measurements for single DNA molecule size under strong nanoslit confinement. Very low ionic strength conditions not only increase the DNA persistence length dramatically, but also cause DNA molecules to swell to the extent that the effective diameter of DNA becomes larger than the nanoslit height. By accounting for these effects, our results and theory provide a reasonable clue for a current controversy regarding the dependence of the DNA conformation on slit height (), persistence length (), and effective diameter ().
View Article and Find Full Text PDFACS Appl Mater Interfaces
August 2014
Polymer residue-free graphene nanoribbons (GNRs) of 200 nm width at 1 μm pitch were periodically generated in an area of 1 cm(2) via laser interference lithography using a chromium interlayer prior to photoresist coating. High-quality GNRs were evidenced by atomic force microscopy, micro-Raman spectroscopy, and X-ray photoelectron spectroscopy measurements. Palladium nanoparticles were then deposited on the GNRs as catalysts for sensing hydrogen gases, and the GNR array was utilized as an electrically conductive path with less electrical noise.
View Article and Find Full Text PDFNanoscale metal ring and dot catalyst arrays are printed over large substrate areas using vertically aligned carbon-based stamps with the ring- and dot-shaped tips. The fundamental nature of these ring and dot catalysts is successfully compared by applying them in diverse electrocatalytic reactions in acidic and alkaline media.
View Article and Find Full Text PDFBy combining nanoimprint lithography technique and a two-step lift-off process, a Si nanotube array is fabricated and applied as a light absorber for n-Si/PEDOT:PSS hybrid solar cells. The light is effectively trapped within the nanotubes and the device reveals a Jsc of 29.9 mA · cm(-2) and a power conversion efficiency of 10.
View Article and Find Full Text PDFThis paper reports a novel and efficient strategy for fabricating sub-100 nm metal ring arrays using a simple printing process. Vertically aligned carbon nanotubes that are supported by hexagonally ordered channels of alumina matrices are used as a stamp to print nanoscale ring patterns, which is a very unique stamping platform that has never been reported. Using this strategy, uniform nanoring patterns of various metals can be directly printed onto a wide range of substrate surfaces under ambient conditions.
View Article and Find Full Text PDFWe report the systematic study of 3D ZnO/Si branched nanowire (b-NW) photoelectrodes and their application in solar water splitting. We focus our study on the correlation between the electrode design and structures (including Si NW doping, dimension of the trunk Si and branch ZnO NWs, and b-NW pitch size) and their photoelectrochemical (PEC) performances (efficiency and stability) under neutral conditions. Specifically, we show that for b-NW electrodes with lightly doped p-Si NW core, larger ZnO NW branches and longer Si NW cores give a higher photocathodic current, while for b-NWs with heavily doped p-Si NW trunks smaller ZnO NWs and shorter Si NWs provide a higher photoanodic current.
View Article and Find Full Text PDFWe report the fabrication of three-dimensional (3D) branched nanowire (NW) heterostructures, consisting of periodically ordered vertical Si NW trunks and ZnO NW branches, and their application for solar water splitting. The branched NW photoelectrodes show orders of magnitudes higher photocurrent compared to the bare Si NW electrodes. More interestingly, selective photoelectrochemical cathodic or anodic behavior resulting in either solar water oxidation or reduction was achieved by tuning the doping concentration of the p-type Si NW core.
View Article and Find Full Text PDFAll-solution-processed transparent thin film transistors (TTFTs) are demonstrated with silver grid source/drain electrodes, which are fabricated by printing and subsequent silver nanoparticles solution coating, which allows continuous processing without using high vacuum systems. The silver grid electrode shows a reasonable transmittance in visible range, moderate electrical conductance and mechanical strength. The TTFTs are employed to drive liquid crystal cells and demonstrate a successful switching operation.
View Article and Find Full Text PDFOne-dimensional (1-D) SnO(2) nanorods (NRs) with a rutile structure are grown on various substrates regardless of the lattice-mismatch by using a new nutrient solution based on tin oxalate, which generated supersaturated Sn(2+) sources. These affluent sources are appropriate for producing a large number of SnO(2) nanoparticles, sufficient for stacking on a substrate surface by gravity, which then acts as a seed layer for subsequent nanorod growth. Single crystalline nanorods are grown along the [001] direction by the oriented attachment phenomenon in which the attached nanoparticles were rearranged to reduce the overall surface energy through sharing thermodynamically unstable crystal (001) planes.
View Article and Find Full Text PDFA periodically aligned array of graphene nanorings (GRNRs) with a sub-15 nm linewidth at a pitch of 450 nm is fabricated with a large area, 9 cm(2) , through conventional nanoimprint lithography coupled with sophisticated metal deposition and plasma-etching processes. The existence of the single-layer GRNRs is verified by various techniques.
View Article and Find Full Text PDFThis work reports an efficient method to fabricate hexagonally patterned metal nanodot arrays at the sub-100-nm scale, which is based on contact printing via novel nanometer-scaled stamps. Vertically aligned carbon nanoposts, supported by hexagonally ordered nanochannels of anodic aluminum oxide templates, are employed as the stamping platform to directly transfer controlled metal nanodot arrays. Using the fabrication platform, a number of patterned metal nanodot arrays made of Au, Cu, Ni, Ag, Pt, Al, and Ti can be contact-printed over large substrate areas in ambient conditions.
View Article and Find Full Text PDFSingle crystalline vertical ZnO nanorods were grown in a one hole-one rod configuration using a hydrothermal method with a patterned polymer template generated by nanoimprint lithography, allowing precise control over the position and density of the ZnO nanorods. An 8×8 ZnO nanorod-based ultraviolet photodetector array is demonstrated, in which a well-confined number of ZnO nanorods are sandwiched between crossbar-type platinum and indium tin oxide electrodes (e.g.
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