Label-free colorimetric analysis strategies based on adsorption-responsive surface-enhanced photochromic phenomena of tungsten(VI) oxide nanoparticles for amino acids.

Herein, we present a colorimetric detection method based on the surface-enhanced photochromic phenomenon of tungsten (VI) oxide (WO) nanocolloid particles for α-amino acid (AA) molecules, including -aspartic acid (Asp), -glutamic acid (Glu), -histidine (His), -isoleucine (Ile), -leucine (Leu), -lysine (Lys), -phenylalanine (Phe), and -valine (Val). The UV-induced photochromic phenomena in the AA/WO binary aqueous systems were investigated using UV-Vis absorption spectrometry. The adsorption properties of the AA molecules on the surface of the WO nanocolloid particles have been identified using a combination of adsorption isotherm analysis and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy.

Cyclodextrin-Assisted Surface-Enhanced Photochromic Phenomena of Tungsten(VI) Oxide Nanoparticles for Label-Free Colorimetric Detection of Phenylalanine.

Herein are presented the results of experiments designed to evaluate the effectiveness of host-guest interactions in improving the sensitivity of colorimetric detection based on surface-enhanced photochromic phenomena of tungsten(VI) oxide (WO) nanocolloid particles. The UV-induced photochromic coloration of WO nanocolloid particles in the presence of aromatic α-amino acid (AA), l-phenylalanine (Phe) or l-2-phenylglycine (Phg), and heptakis(2,3,6-tri--methyl)-β-cyclodextrin (TMβCDx) in an aqueous system was investigated using UV-vis absorption spectrometry. The characteristics of the adsorption modes and configurations of AAs on the WO surface have also been identified by using a combination of adsorption isotherm analysis and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR).

Exploring evolutionary trends within the Pennellidae (Copepoda: Siphonostomatoida) using molecular data.

The family Pennellidae comprises ecto- and mesoparasitic copepods on marine fishes. Although a preliminary scheme of phylogenetic relationships of pennellids based on morphological characters exists, it is difficult to objectively define character states because of their highly modified bodies and reduced appendages. This molecule-based study analysed phylogenetic relationships among seven genera and 12 species of pennellids, using 18S and 28S ribosomal DNA sequences in order to infer evolutionary trends within the family.

Hemocyte migration and expression of four Sox genes during wound healing in Pacific abalone, Haliotis discus hannai.

In molluscs, migration of hemocytes and epithelial cells is believed to play central roles in wound healing. Here, we assessed cellular and molecular mechanisms of wound healing in Pacific abalone, a marine gastropod. Light and electron microscopy in the wounds showed early accumulation of putative hemocytes, collagen deposition by fibroblasts, and further coverage of this tissue by migration of adjacent epithelial cells.

A new species of (Copepoda, Calanoida, Arietellidae) from the hyperbenthic layer of Japan, with a molecular phylogenetic analysis of some representative genera of the Arietellidae.

A new species of the continental shelf hyperbenthic genus is described, the first from the Indo-Pacific. This is the second species of known, and the first description of a male in the genus. The new species is easily distinguished from other species of () based on: (1) short caudal rami, approximately 1.

Discovery of the fish host of the 'planktonic' caligid Shen & Li, 1959 (Crustacea: Copepoda: Siphonostomatoida).

The siphonostomatoid copepod Shen & Li, 1959 has been widely reported from plankton samples obtained from neritic and oceanic waters off coasts of the Indo-West Pacific and Atlantic Oceans. Until now, its fish host has remained unknown. This copepod belongs to an intriguing group of congeners that, despite being part of a chiefly parasitic group, are consistently found as zooplankters.

Genetic structure of Japanese sea cucumbers (Apostichopus japonicus) along the Sanriku coast supports the effect of earthquakes and related tsunamis.

The Japanese common sea cucumber (Apostichopus japonicus) is a major marine product from Sanriku, Japan, but its populations were severely affected by the 2011 Tohoku earthquake, possibly decreasing its genetic diversity and increasing its extinction risk. In this study, we estimated the genetic structure and diversity of sea cucumbers from Touni and Yamada Bays of Sanriku over 4 years after the earthquake. The between-population genetic structure was estimated using two mitochondrial DNA regions (cytochrome c oxidase subunit I and 16S rDNA).

Kinetics of Coloration in Photochromic Tungsten(VI) Oxide/Silicon Oxycarbide/Silica Hybrid Xerogel: Insight into Cation Self-diffusion Mechanisms.

Silicon oxycarbide/silica composites with well-dispersed tungsten(VI) oxide (WO3) nanoparticles were obtained as transparent hybrid xerogels via an acid-catalyzed sol-gel process (hydrolysis/condensation polymerization) of 3-(triethoxysilyl)propyl methacrylate (TESPMA) and tetraethoxysilane (TEOS). The self-diffusion mechanism of alkali-metal cations and the kinetics of the photochromic coloration process in the WO3/TESPMA/TEOS hybrid xerogel systems have been systematically investigated. Under continuous UV illumination, a gradual color change (colorless → blue) corresponding to the reduction of W(6+) into W(5+) states in WO3 nanoparticles can be confirmed from the WO3/TESPMA/TEOS hybrid xerogels containing alkali-metal sulfates, although no coloration of the hybrid xerogel without alkali-metal sulfate was observed.

Photochromic Properties of Tungsten Oxide/Methylcellulose Composite Film Containing Dispersing Agents.

Tungsten oxide-based photochromic films which changed reversibly in air between colorless- transparent in the dark and dark blue under UV irradiation were prepared by using methylcellulose as a film matrix and polyols such as ethylene glycol (EG), propylene glycol (PG), and glycerin (Gly) as dispersing agents. Influence of the dispersing agents and water in the films on the photochromic behavior was systematically studied. Under UV irradiation, absorption bands around 640 and 980 nm increased and the coloring rate was the following order: Gly > EG > PG.

Solid-Phase Combinatorial Synthesis and Biological Evaluation of Destruxin E Analogues.

The solid-phase combinatorial synthesis of cyclodepsipeptide destruxin E has been demonstrated. The combinatorial synthesis of cyclization precursors 8 was achieved by using a split and pool method on SynPhase Lanterns. The products were successfully macrolactonized in parallel in the solution phase by using 2-methyl-6-nitrobenzoic anhydride and 4-(dimethylamino)pyridine N-oxide to afford macrolactones 9, and the subsequent formation of an epoxide in the side chain gave 18 member destruxin E analogues 6.

Mechanism of peripheral substituent effects on adsorption-aggregation behaviors of cationic porphyrin dyes on tungsten(VI) oxide nanocolloid particles.

The adsorption and aggregation behaviors of the cationic porphyrin derivatives such as 5,10,15,20-tetrakis(4-pyridyl)porphyrin [TPyP], 5,10,15,20-tetrakis(N-methyl-4-pyridyl)porphyrin [TMPyP], 5,10,15,20-tetrakis(N-ethyl-4-pyridyl)porphyrin [TEPyP], and 5,10,15,20-tetrakis(N-n-propyl-4-pyridyl)porphyrin [TPPyP] (hereafter called "TPyP derivatives") in the tungsten(VI) oxide (WO3) colloid aqueous solution at weak acidic pH were studied by UV-vis spectroscopy. The TPyP derivatives were strongly adsorbed as monolayer onto the WO3 surface via the electrostatic interaction between their peripheral cationic substituents and negatively surface-charged WO3 colloid particles, and most of the ones adsorbed eventually formed J-type dimers aligned in the head-to-tail fashion. These different dimerization states were effectively analyzed by the change of ratios among the intensities of exciton split Soret bands (H- and J-bands).

Surface-enhanced photochromic phenomena of phenylalanine adsorbed on tungsten oxide nanoparticles: a novel approach for "label-free" colorimetric sensing.

The enhanced photochromic behaviors of the L-phenylalanine (Phe)-tungsten(VI) oxide (WO3) colloid binary aqueous solution have been investigated by means of UV-vis absorption spectrometry. The phenomena provided a potential use of the WO3 nanoparticles as a colorimetric probe for sensitive "label-free" detection of Phe.

Photocatalytic degradation of chlorinated ethanes in the gas phase on the porous TiO(2) pellets: effect of surface acidity.

The photocatalytic degradation of chlorinated ethanes was studied in a tubular photoreactor packed with TiO(2) pellets prepared by sol-gel method. The steady-state condition was not obtained, but the deterioration in the photocatalytic activity was observed during the irradiation. Effects of mole fractions of water vapor, O(2), and C(2)H(5)Cl or C(2)H(4)Cl(2) and reaction temperature on the photodegradation of C(2)H(5)Cl or C(2)H(4)Cl(2) were examined, and these data were compared with those obtained by the photodegradation of chlorinated ethylenes.

Measuring the optical chirality of molecular aggregates at liquid-liquid interfaces.

Some new experimental methods for measuring the optical chirality of molecular aggregates formed at liquid-liquid interfaces have been reviewed. Chirality measurements of interfacial aggregates are highly important not only in analytical spectroscopy but also in biochemistry and surface nanochemistry. Among these methods, a centrifugal liquid membrane method was shown to be a highly versatile method for measuring the optical chirality of the liquid-liquid interface when used in combination with a commercially available circular dichroism (CD) spectropolarimeter, provided that the interfacial aggregate exhibited a large molar absorptivity.

Controllable adsorption and ideal H-aggregation behaviors of phenothiazine dyes on the tungsten oxide nanocolloid surface.

The monomer-aggregate equilibrium of four phenothiazine (PN) dyes, containing thionine (TH), methylene blue (MB), new methylene blue (NMB), and 1,9-dimethylmethylene blue (DMB), in the tungsten(VI) oxide (WO(3)) nanocolloid solution has been investigated by means of UV-vis spectroscopy. Addition of PN dye into the WO(3) nanocolloid solution brought about significant changes in the absorption spectrum, suggesting the formation of H-type (face-to-face fashion) trimer on the WO(3) nanocolloid surface. The adsorptivity of PN dyes onto the WO(3) nanocolloid surface was diminished by the raising the ionic strength, indicating the evidence of the electrostatic interaction between cationic PN dye and negatively charged WO(3) nanocolloids.

Linear dichroism of Zn(II)-tetrapyridylporphine aggregates formed at the toluene/water interface.

The apparent circular dichroism (CD) and the linear dichroism (LD) spectra of the aggregates of achiral zinc(II)-5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine (ZnTPyP), formed at the toluene/water interface in a centrifugal liquid membrane (CLM) cell, were investigated by comparison with the microscopic CD and LD spectra of a single interfacial aggregate of ZnTPyP about 100 mum in length, measured by a microscope-spectropolarimeter. The interfacial ZnTPyP aggregate showed two types of flat trapezoidal shapes, one had a seedlike core at an edge (type I) and another a needlelike core at an edge (type II). The microscopic CD and LD spectra were observed by varying the angle between the parallel axis of the trapezoidal aggregate and the perpendicular axis of a polarized light for LD.

Binding behavior of subphthalocyanine-tagged testosterone with human serum albumin at the n-hexane/water interface.

Subphthalocyaninatoboron(III) was applied for the first time as a novel marker-tag of testosterone (Subpc-test) for the binding analysis with human serum albumin (HSA) at a liquid/liquid interface. The binding interaction of Subpc-test with HSA at the n-hexane/water interface was studied by UV-visible absorption and circular dichroism (CD) spectroscopy combined with a centrifugal liquid membrane cell at different pHs of aqueous solutions. Complementary studies by a high-speed stirring experiment and an interfacial tension measurement were also performed to characterize the interfacial adsorptivity of Subpc-test and HSA molecules, respectively.

Control of optically active structure of thioether-phthalocyanine aggregates by chiral Pd(II)-BINAP complexes in toluene and at the toluene/water interface.

The Pd(II)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (BINAP)-mediated chiral assembly of thioether-derivatised phthalocyanatomagnesium(II) compounds (MgPc(SR)8, SR is benzylthio (SBz) or benzhydrylthio (Bh)) was formed in toluene and at the toluene/water interface, and investigated by means of UV-Vis absorption and circular dichroism (CD) spectroscopy combined with the centrifugal liquid-membrane (CLM) devise. Interfacial tension measurements indicated that, in the presence of PdSO4 in the aqueous phase, BINAP ligand adsorbed as a monolayer forming Pd(II)BINAP2+ complex at the toluene/water interface. UV-Vis absorption spectrum of MgPc(SR)8 in the Q-band region was blue-shifted in toluene upon addition of [Pd(II)BINAP]Cl2, but red-shifted at the toluene/water interface when Pd(II)BINAP2+ was formed at the interface.

Site-selective formation of optically active inclusion complexes of alkoxo-subphthalocyanines with beta-cyclodextrin at the toluene/water interface.

Several subphthalocyanine derivatives that contain an alkoxo substituent as an axial ligand (RO-Subpc, R = 9-anthracenemethyl, benzyl, phenyl, 3,5-dimethylbenzyl, 3,5-dimethylphenyl, 4-methylbenzyl, and 4-methylphenyl) were synthesized. The formation of inclusion complexes of RO-Subpc with beta-CD in DMSO and at the toluene/water interface was investigated by UV/Vis absorption spectroscopy, induced circular dichroism (ICD), and nuclear magnetic resonance (NMR) measurements. Interfacial tension measurements suggested that beta-CD adsorbed as a monolayer at the toluene/water interface and probably orientated towards the toluene phase with its primary face.

Aggregation of thioether-substituted subphthalocyanines with palladium(ii) at the toluene-water interface.

Novel chloro-subphthalocyaninatoboron()(Subpc) derivatives with six thioether at the 2 and 3 positions of peripheral benzene (Subpc(SR)) such as chloro-[2,3,9,10,16,17-hexakis-ethylthio-subphthalocyaninato]boron()(Subpc(SEt)) and chloro-[2,3,9,10,16,17-hexakis-benzylthio-subphthalocyaninato]boron()(Subpc(SBz)) were synthesized. The interfacial adsorption of Subpc and Subpc(SR), and the interfacial aggregation of Subpc(SR)-Pd() complexes in the toluene-water system have been investigated by means of high-speed stirring (HSS) spectrometry, centrifugal liquid-membrane (CLM) spectrometry, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS). Characteristically orientated structures of Subpc(SR) molecules and the aggregates of Subpc(SR)-Pd() complexes at the toluene-water interface have been suggested depending on the structures of Et and Bz at the periphery.