Dispersion of single-walled carbon nanotubes modified with poly-l-tyrosine in water

In this study, complexes composed of poly-l-tyrosine (pLT) and single-walled carbon nanotubes (SWCNTs) were produced and the dispersibility of the pLT/SWCNT complexes in water by measuring the ζ potential of the complexes and the turbidity of the solution were investigated. It is found that the absolute value of the ζ potential of the pLT/SWCNT complexes is as high as that of SWCNTs modified with double-stranded DNA (dsDNA) and that the complexes remain stably dispersed in the water at least for two weeks. Thermogravimetry analysis (TGA) and visualization of the surface structures of pLT/SWCNT complexes using an atomic force microscope (AFM) were also carried out

An aluminum shield enables the amphipod Hirondellea gigas to inhabit deep-sea environments.

The amphipod Hirondellea gigas inhabits the deepest regions of the oceans in extreme high-pressure conditions. However, the mechanisms by which this amphipod adapts to its high-pressure environment remain unknown. In this study, we investigated the elemental content of the exoskeleton of H. gigas specimens captured from the deepest points of the Mariana Trench. The H. gigas exoskeleton contained aluminum, as well as a major amount of calcium carbonate. Unlike other (accumulated) metals, aluminum was distributed on the surface of the exoskeleton. To investigate how H. gigas obtains aluminum, we conducted a metabolome analysis and found that gluconic acid/gluconolactone was capable of extracting metals from the sediment under the habitat conditions of H. gigas. The extracted aluminum ions are transformed into the gel state of aluminum hydroxide in alkaline seawater, and this gel covers the body to protect the amphipod. This aluminum gel is a good material for adaptation to such high-pressure environments

Chemical synthesis and cytotoxicity of neo-glycolipids; rare sugar-glycerol-lipid compounds

Rare sugars are defined as monosaccharides and their derivatives, which rarely exist in nature and have various beneficial effects on organisms, biomaterials and foods. Glycolipids are composed of sugars and lipids and have been intensively studied in various fields such as environmental engineering, nanotechnology and molecular biology. Here, we synthesise new types of glycolipids composed of rare sugars, glycerol and lipids (RSGLs), using 6 different types of rare sugars by combining the modified Fischer and lipase reverse reactions. We confirm the production of RSGLs by thin layer chromatography (TLC), Fourier-transform infrared (FT-IR) spectroscopy and matrix assisted laser desorption/ionisation time of flight mass spectroscopy (MALDI-TOF-MS) and investigate the cytotoxicity of RSGLs by lactate dehydrogenase (LDH) and alamar blue assays. We successfully synthesise novel RSGLs; i.e., D-ribose-glycorol-lipid, D-allose-glycorol-lipid, L-rhamnose-glycorol-lipid, L-lyxorse-glycorol-lipid, L-gulose-glycorol-lipid and L-fucose-glycorol-lipid. We finally clarify the effect of the concentration of those RSGLs on cytotoxicity, which is of great importance considering the utilisation of RSGLs particularly in the field of biomedicine

One-pot green synthesis of Ag nanoparticle-decorated reduced graphene oxide composites: effect of Ag/graphene oxide volume ratio and its demonstration as low-voltage on-chip photodetector

We present one-pot synthesis of silver nanoparticle-decorated reduced graphene oxide (AgNP-rGO) composite by utilizing ascorbic acid as a green reduction agent. The effect of volume ratio between Ag(NH3)2OH complex solution and GO solution was studied. High content of Ag volume seems to slower down the reduction of GO, hence providing high nucleation sites for the Ag ions to be reduced to nanoparticles with much higher density. Meanwhile, due to high reduction rate of GO at low content of Ag volume, it produces less density of nanoparticles with larger particle size. The composite was successfully demonstrated as a low-voltage on-chip photodetector. The presence of high-density AgNPs on rGO results to fast response (393 nA/s) and recovery rate (399 nA/s) with excellent cyclic stability even at low biasing voltage of 1 [V] due to the effective localized plasmon resonance of AgNPs. The detectivity and responsivity remarkably increase with the densities of AgNPs and the biasing voltages, where these values can increase from 3.58 × 105 cm Hz1/2 W−1 and 2.2 × 10−6 A/W at 1 [V] up to 2.12 × 108 cm Hz1/2 W−1 and 3.8 × 10−2 A/W at 20 [V], respectively, for the sample with Ag volume of 75%

far red fluorescent carbon nano onions as a biocompatible platform for cellular imaging

Fluorescent carbon nano-onions emitting in the far-red spectral window with enhanced solubility in biological media and bright photoluminescence are reported

Synthesis of an Ultradense Forest of Vertically Aligned Triple-Walled Carbon Nanotubes of Uniform Diameter and Length Using Hollow Catalytic Nanoparticles

It still remains a crucial challenge to actively control carbon nanotube (CNT) structure such as the alignment, area density, diameter, length, chirality, and number of walls. Here, we synthesize an ultradense forest of CNTs of a uniform internal diameter by the plasma-enhanced chemical vapor deposition (PECVD) method using hollow nanoparticles (HNPs) modified with ligand as a catalyst. The diameters of the HNPs and internal cavities in the HNPs are uniform. A monolayer of densely packed HNPs is self-assembled on a silicon substrate by spin coating. HNPs shrink via the collapse of the internal cavities and phase transition from iron oxide to metallic iron in hydrogen plasma during the PECVD process. Agglomeration of catalytic NPs is avoided on account of the shrinkage of the NPs and ligand attached to the NPs. Diffusion of NPs into the substrate, which would inactivate the growth of CNTs, is also avoided on account of the ligand. As a result, an ultradense forest of triple-walled CNTs of a uniform internal diameter is successfully synthesized. The area density of the grown CNTs is as high as 0.6 × 10¹² cm^–2. Finally, the activity of the catalytic NPs and the NP/carbon interactions during the growth process of CNTs are investigated and discussed. We believe that the present approach may make a great contribution to the development of an innovative synthetic method for CNTs with selective properties