Masanari Okuno

Nonmagnetic materials in a magnetic ionic liquid, which has a very large magnetic susceptibility, respond to a magnet as if they are strongly diamagnetic. The trajectory of deflected nitrogen gas bubbles in 1-butyl-3-methylimidazolium tetrachloroferrate has been measured. It shows a good agreement with theory. Nonmagnetic materials can be transported and separated in a magnetic ionic liquid, according to their density and magnetic susceptibility by regulating magnetic field and its gradient.

We have developed a multifocus confocal Raman microspectroscopic system for the fast multimode vibrational imaging of living cells. It consists of an inverted microscope equipped with a microlens array, a pinhole array, a fiber bundle, and a multichannel Raman spectrometer. Forty-eight Raman spectra from 48 foci under the microscope are simultaneously obtained by using multifocus excitation and image-compression techniques. The multifocus confocal configuration suppresses the background generate

Subnanosecond supercontinuum (SC) has been generated by a 1,064 nm microchip laser combined with a photonic crystal fiber. The ultrabroadband (>2,000 cm(-1)) SC has facilitated multiplex coherent anti-Stokes Raman scattering (CARS) microspectroscopy in the spectral range from 1,000 to 3,000 cm(-1) with lateral and depth spatial resolution of 0.9 and 4.6 microm, respectively. A clear CARS image of a Nicotiana tabacum L. cv. Bright Yellow 2 cell has been obtained with high vibrational contrast.

We present complex achiral and chiral vibrational sum frequency generation (VSFG) spectra at the air/water interface of protein solutions by using heterodyne-detected VSFG. Bovine serum albumin, pepsin, concanavalin A, and α-chymotrypsin were measured as model proteins. The obtained achiral Im[χ(2)] spectra gave us insights into the molecular orientation of protein molecules and water at the interface. From the chiral Im[χ(2)] spectra in the NH stretching and amide I regions, the secondary struc

We first demonstrated chiral vibrational sum frequency generation (VSFG) in the heterodyne detection, which enables us to uniquely determine chiral second-order nonlinear susceptibility consisting of phase and amplitude and distinguish molecular chirality with high sensitivity. Liquid limonene was measured to evaluate the heterodyne-detected chiral VSFG developed in this study. R-(+)- and S-(-)-limonene showed clearly opposite signs in the complex spectra of the second-order nonlinear susceptibi

Abstract Hyper‐Raman (HR) measurements of four simple alcohols have been demonstrated. High‐quality HR spectra with high signal to noise ratios allow us to discuss spectral features in detail. Measured HR spectra are compared with IR and Raman spectra. High similarities between HR and IR spectra are found both in the fingerprint and the CH stretching regions. Meanwhile, HR and IR spectra show differences in spectral features including relative intensities of the OH stretch to the CH stretches. B

We have developed ultrabroadband (>2000 cm(-1)) multiplex coherent anti-Stokes Raman scattering (CARS) spectroscopy using a subnanosecond (sub-ns) microchip laser source. A photonic crystal fiber specifically designed for sub-ns supercontinuum (SC) generation has been used for obtaining ultrabroadband Stokes radiation, which enables us to achieve simultaneous vibrational excitation in the range from 800 to 3000 cm(-1). We have successfully obtained multiplex CARS spectra for several molecular li

The impact of the vibrational coupling of the OH stretch mode on the spectra differs significantly between IR and Raman spectra of water. Unified understanding of the vibrational couplings is not yet achieved. By using a different class of vibrational spectroscopy, hyper-Raman (HR) spectroscopy, together with machine-learning-assisted HR spectra calculation, we examine the impact of the vibrational couplings of water through the comparison of isotopically diluted H₂O and pure H<sub>2<

We have demonstrated hyper-Raman (HR) spectroscopy of <i>N</i>-methylacetamide (NMA) for the first time. Fundamental knowledge of amide bands in HR spectra has been obtained. HR spectra of NMA exhibit various amide bands with different intensity patterns from Raman and IR spectra. The amide III and II signals were strongly observed, suggesting the possible application of HR spectroscopy to analyze secondary structures, complementary to IR and Raman spectroscopy. The peak positions of HR amide ba

Hyper-Raman (HR) spectra of polar liquids are reported. Acetone, acetonitrile, chloroform, and dimethyl sulfoxide in the liquid phase were measured by using a picosecond laser whose wavelength is 1064 nm and repetition rate is 200 kHz. HR spectra with a high signal to noise ratio were obtained without the surface enhancement or the electronic resonance effect. Due to the improvement of the sensitivity, many vibrational bands were first observed in HR spectroscopy. The peak frequencies, relative

Heterodyne-detected vibrationally electronically doubly resonant chiral sum-frequency generation (HD-DR chiral SFG) spectra were observed for the first time on monolayers. Langmuir monolayers of R- and S-binaphthyl amphiphiles on water exhibited complex chiral vibrational sum frequency generation (VSFG) spectra whose amplitudes were approximately the same, but whose phases were different by π. By comparing the electronic resonance profiles of the chiral VSFG signal amplitude and phase with simul

Dendrimeric macromolecules with defined shape and size are promising candidates for delivering drug or DNA molecules into cells. In this work we study the influence of an amphiphilic polyphenylene dendrimer on a model cell membrane consisting of a condensed 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid monolayer. A small surface pressure decrease is observed when the dendrimer solution is injected into the aqueous phase below the monolayer. X-ray reflectivity measurements show that th

The mechanism of surfactant-induced cell lysis has been studied with quantitative coherent anti-Stokes Raman scattering (CARS) microspectroscopy. The dynamics of surfactant molecules as well as intracellular biomolecules in living Chinese Hamster Lung (CHL) cells has been examined for a low surfactant concentration (0.01 w%). By using an isotope labeled surfactant having CD bonds, surfactant uptake dynamics in living cells has been traced in detail. The simultaneous CARS imaging of the cell itse

Der Prozess des Zelltods wurde in Echtzeit auf subzellulärer Ebene mithilfe von kohärenter Anti-Stokes-Raman-Mikrospektroskopie verfolgt. Diese Weiterentwicklung der Anti-Stokes-Raman-Streuungs(CARS)-Mikroskopie zeigt Veränderungen des chemischen Kontrastes beim Zelltod in deutlicher Auflösung (siehe Bild). Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as subm

Polarization dependence of heterodyne-detected chiral vibrational sum frequency generation (VSFG) was examined for thin films of polylactic acids and neat limonene liquid far from electronic resonance. The enantiomers of polylactic acid films on silica substrates were successfully distinguished, and their chiral VSFG signals were ascribed not to bulk but to the interfaces by comparing chiral signals observed in reflection in the S-polarized VSFG, P-polarized visible, and P-polarized infrared and