Ichiro Tanabe 교수

Optical control of size, shape, or orientation of a metal nanoparticle is important for development of nanoscale optical devices and elements of photonic circuits. Thus far, however, independent control of two or more parameters has not yet been achieved. Here we place a simple spherical Ag nanoparticle on TiO(2) with high refractive index and separate a plasmon mode localized at the Ag-TiO(2) interface from the other mode distributed over the nanoparticle. Selective excitation of each mode give

Aluminum has recently attracted considerable interest as a plasmonic material due to its unique optical properties, but most work has been limited to nanostructures. We report here SPR biosensing with aluminum thin-films using the standard Kretschmann configuration that has previously been dominated by gold films. Electron-beam physical vapor deposition (EBPVD)-prepared Al films oxidize in air to form a nanofilm of Al₂O_3, yielding robust stability for sensing applications i

Electronic absorption spectra of imidazolium-based ionic liquids were studied by far- and deep-ultraviolet spectroscopy and quantum chemical calculations. The absorption spectra in the 145-300 nm region of imidazolium-based ionic liquids, [Cnmim](+)[BF4](-) (n = 2, 4, 8) and [C4mim](+)[PF6](-), were recorded using our original attenuated total reflectance (ATR) system spectrometer. The obtained spectra had two definitive peaks at ∼160 and ∼210 nm. Depending on the number of carbon atoms in the a

Absorption spectra (150-300 nm) of TiO2 and TiO2 modified with metal (Pt, Pd, and Au) nanoparticles were systematically measured using an attenuated total reflection-far ultraviolet spectrometer. The deposition of metal nanoparticles altered the spectral shape and intensity, indicating changes in the electronic states and photocatalytic activities of TiO2.

Surface plasmon resonance (SPR) sensors detect refractive index changes on metal thin films and are frequently used in aqueous solutions as bio- and chemical-sensors. Recently, we proposed new SPR sensors using aluminum (Al) thin films that work in the far- and deep-ultraviolet (FUV-DUV, 120-300 nm) regions and investigated SPR properties by an attenuated total reflectance (ATR) based spectrometer. The FUV-DUV-SPR sensors are expected to have three advantages compared to visible-SPR sensors: hig

Various far and deep ultraviolet spectroscopic investigations provide a basic understanding of the properties of TiO₂and promising possibilities for its applications.

Absorption spectra of anatase and rutile TiO2 in the 150-300 nm region before and after the deposition of Pt nanoparticles were measured. For anatase TiO2, the spectral intensity in the longer wavelength region decreased (>∼210 nm), while that in the shorter wavelength region increased (<∼210 nm). In particular, spectral band intensity in the far-ultraviolet (FUV) region (∼160 nm) was increased. In contrast, the spectral intensity of rutile TiO2 increased over the entire wavelength region under

Recently, far-ultraviolet (FUV) spectroscopy, which is the spectroscopy of wavelengths in the region 140-200 nm, of solid and liquid states has received significant attention as a novel spectroscopic method. FUV spectroscopy provides new possibilities for studying electronic structures and transitions in almost all types of molecules, from water to polymers. It also shows great promise for a variety of applications. It is well known that wavelengths below 200 nm are rich in information regarding

While there was little shape dependence, smaller Au nanoparticles induced larger electronic state changes and higher photocatalytic activities.

Changes in morphology and optical properties of single Ag nanoplates on a nanoparticulate TiO2 film were studied by means of combined atomic force microscopy and optical dark-field microscopy with the aid of discrete dipole approximation-based spectral simulation. Photocatalytic reduction of Ag+ ions under diffusion-controlled conditions grows hexagonal and triangular Ag nanoplates mostly in vertical orientation. The Ag nanoplates absorb and scatter light at different wavelengths on the basis of

Despite providing rich information on electronic states, the far-ultraviolet (FUV, <200 nm) and deep-ultraviolet (DUV, <300 nm) absorption spectra of ionic liquids (ILs) are difficult to obtain without saturation due to very strong analyte absorbance. Herein, FUV-DUV spectra of selected ILs were systematically and easily recorded using an attenuated total reflectance spectrometer and rationalized based on quantum chemical calculations. ILs containing pyrrolidinium or ammonium cations and fluorin

The surface plasmon resonance (SPR) of Al thin films was investigated by varying the refractive index of the environment near the films in the far-ultraviolet (FUV, 120-200 nm) and deep-ultraviolet (DUV, 200-300 nm) regions. An original FUV-DUV spectrometer that adopts an attenuated total reflectance (ATR) system was used. The measurable wavelength range was down to the 180 nm, and the environment near the Al surface could be controlled. The resultant spectra enabled the dispersion relationship

Triangular and hexagonal Ag nanoplates deposited on a TiO(2) film in a mostly vertical orientation topple under visible light, resulting in a decrease of extinction at the excitation wavelength and increase at longer wavelengths.

In this study, surface plasmon resonance (SPR) wavelength shifts due to molecular electronic absorptions in the far-ultraviolet (FUV, < 200 nm) and deep-ultraviolet (DUV, < 300 nm) regions were investigated by attenuated total reflectance (ATR) spectroscopy. Due to the strong absorption in the DUV region, N,N-dimethylformamide (DMF) significantly increased the SPR wavelength shift of Al film. On the other hand, no such shift enhancement was observed in the visible region for Au film because DMF

Far- and deep-ultraviolet spectra (150-300 nm) of semiconductor nanoparticles (zinc oxide and zinc sulfide) are successfully measured by using attenuated total reflectance (ATR) spectroscopy, and analyzed using finite-difference time-domain (FDTD) simulations. The obtained spectra show good consistency with earlier synchrotron-radiation spectra and with theoretical calculations. The FDTD simulation results show that the present system collected the correct spectra. In the present system, the obt