Voltammetric response of phenylboronic acid monolayer-modified gold electrode to sugars.

The surface of a gold (Au) disk electrode was modified with a self-assembled monolayer consisting of phenylboronic acid moiety to fabricate a voltammetric sensor sensitive to sugars. The modified Au electrode exhibited a voltammetric response to sugars in the presence of Fe(CN)6(3-) ion in the sample solution at neutral pH. The peak current of the cyclic voltammograms decreased depending on the type and concentration of sugars. The dynamic range of the electrode is 3 - 100 mM for glucose and mannose and 1 - 30 mM for fructose. The sugar sensor can be used repeatedly after rinsing in 10 mM acetate buffer (pH 4.5).     

Plasma Enhanced Chemical Vapor Deposition of Fluorinated Amorphous Carbon Thin Films from Tetrafluoroethylene and Tetraisocyanatesilane

Fluorinated amorphous carbon films were prepared from tetrafluoroethylene (TFE; C₂F₄) and tetraisocyanatesilane (TICS; Si(NCO)₄) using an RF plasma enhanced chemical vapor deposition method for the purpose of application to inter layer low permittivity films used in large scale integrated circuits. Structure of the deposited films was investigated by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Adhesion characteristics were examined by a tape-peel method. Permittivity of the films was investigated from capacitance measurement on metal-insulator-semiconductor structure. The structural analysis revealed that the deposited films contained imide-like group in spite of the fact that TICS molecules contained isocyanate group . The films deposited under the flow ratio TICS/(TFE + TICS) = 70% showed permittivity of 2.3, good adhesion on silicon substrates, and higher thermal stability than the films deposited without TICS.     

Total synthesis of amauromine

Total synthesis of amauromine ($\text{1}$), a novel alkaloid possessing two reversed prenyl groups in its molecule, was described.     

Synthesis, structures, and photophysical properties of silicon and carbon-bridged ladder oligo(p-phenylenevinylene)s and related π-electron systems

A series of partially or fully fused ladder oligo(p-phenylenevinylene)s (LOPVs) and related π-electron systems has been synthesized. Thus, the intramolecular reductive cyclization of o-silyl-substituted bis(phenylethynyl)benzenes with lithium naphthalenide produces partially silicon-bridged bis(styryl)benzenes consisting of silaindene or disilaindacene skeletons. By combining this cyclization with the Friedel-Crafts type electrophilic cyclization, a homologous series of the fully fused LOPVs and related compounds, bearing silicon and carbon bridges, has been synthesized in fairly good yields. The longest example of the LOPVs is the 13-ring-fused system that has a nearly flat π-conjugated framework with a length of 2.9 nm, as proven by X-ray crystallography. All the produced ladder π-electron systems show intense fluorescence in the visible region with high quantum yields as well as relatively small Stokes shifts. As the silicon contents increase or the disilaindacene skeleton is incorporated, the emission maxima shift to the longer wavelengths and the fluorescent quantum yields slightly decrease. These trends can be rationalized as due to the σ* effect of silicon, wherein the silicon bridges contribute to the electronic structure through σ*-π* orbital interaction that cause the red-shifts in the emission maxima and suppress the radiative decay process from the singlet excited state.     

Optimization of Aqueous Stability versus π-Conjugation in Tetracationic Bis(triarylborane) Chromophores: Applications in Live-Cell Fluorescence Imaging

The stability of tetracationic triarylboranes in dilute aqueous solution was investigated by tuning the steric demand of the linker in a (para-(N,N,N-trimethylammonio)xylyl)₂B–(linker)–B(para-(N,N,N-trimethylammonio)xylyl)₂ structure. With increasing steric bulk of the linker, namely 1,4-phenylene, 2,2′′′-(3,3′′′-dimethyl)-5,2′:5′,2′′:5′′,5′′′-quaterthiophene, 9,10-anthracenylene, and 4,4′′′-(5′-(3,5-dimethylphenyl))(5′′-(3′′′,5′′′-dimethylphenyl))-2′,2′′-bithiophene, the stability of the compounds increased. The anthracene-based chromophore, compound 3M is water-stable for at least 48 h, is nontoxic to cells and exhibits an exceedingly high fluorescence quantum yield of 0.86 in water making it an ideal candidate for confocal live-cell imaging of lysosomes.