Yukihiro Ozaki

• Professor
• Professor at Kwansei Gakuin University

In this study, Raman spectra (3700–10 cm –1 ) and attenuated total reflection infrared–far-infrared (ATR-IR/FIR) spectra (4000–50 cm –1 ) including low-frequency region were measured for amorphous rocks, which were five types of obsidians whose formation ages and sources are different and pitchstone to clarify the differences in water content (free...

Micro-Raman spectroscopic analysis of a fossil sample of Vicarya callosa japonica was performed to investigate the chemical process of fossilization. The Vicarya sample, originating from the Miocene Katsuta Group, Okayama prefecture, southwestern Japan, had a conical shell body with multiple protuberances on the outer layer. The interior of the she...

We investigate resonance (true resonance and pre-resonance) Raman (RR) effects in glucose, galactose, N-acetylglucosamine, and N-acetylgalactosamine with ultraviolet resonance Raman (UVRR) and far-ultraviolet (FUV) spectroscopies. Electronic transitions in the FUV region are attributed to electronic orbitals due to σ and π electrons. Their geometri...

Naturally weathered polypropylene (NWPP) samples are useful for investigating the effects of various degradation factors that cannot be obtained in artificial laboratory experiments. In this study, NWPP samples were extracted from beach sediments (Ashiya, Hyogo, Japan). Raman and attenuated total reflection (ATR)–Fourier-transform infrared (FTIR) s...

This review comprehensively presents the fifty-year journey of surface-enhanced Raman spectroscopy (SERS), covering its discovery, pivotal phases, innovative methods, and key inspirations from the pioneers and trailblazers.

Single-crystal structures of four alditol complexes are presented. In LuCl 3 /galactitol and ScCl 3 / myo -inositol complexes, μ 2 -bridge-relevant deprotonations were observed. The polarization from two rare earth ions in the μ 2 -bridge activates the chemically...

Tip-Enhanced Raman Scattering (TERS) has emerged as a revolutionary technique capable of probing matter at the nanoscale, offering unprecedented spatial resolution and sensitivity. This chapter provides a comprehensive overview of the recent advancements in TERS, highlighting its pivotal role in various scientific disciplines. We begin by tracing t...

Oyster fossils are some of the most common bivalve mollusk fossils found all over the world, they are different from other fossils because the oyster is still alive in the present day, and the body structure of modern oyster is almost the same as that of ancient one. Therefore, we designed a control experiment comparing the Raman spectra of mineral...

Plastic pollution at the nanoscale continues to pose adverse effects on environmental sustainability and human health. However, the detection of nanoplastics (NPLs) remains challenging due to limitations in methodology and instrumentation. Herein, a "green approach" for surface-enhanced Raman spectroscopy (SERS) was exploited to detect polystyrene...

Two-dimensional correlation spectroscopy is used to investigate the intermolecular interaction between two substances dissolved in the same solutions, where the intermolecular interaction is described by two reversible reactions producing two supramolecular aggregates. The severe overlappings expected among the characteristic peaks of the original...

Raman images were constructed for polypropylene (PP) films before and after ultraviolet (UV) irradiation (100 mW, 248–436 nm) for 10 h using several intensity ratios of Raman bands that are sensitive to crystallization of PP. In the images of PP films before the irradiation the intensity ratios are nearly uniform for the films but for those of the...

Semiconductor materials represent an ideal choice for designing surface‐enhanced Raman scattering (SERS)‐based sensors due to their superior thermal and chemical stability compared to conventional metal materials. However, current SERS‐active semiconductor substrates have limitations such as low detection sensitivity and often complicated preparati...

This review reports the recent progress on ATR-far ultraviolet (FUV) spectroscopy in the condensed phase.

The combination of Raman imaging and multivariate curve resolution (MCR) or classical least squares (CLS) has allowed us to explore the distribution and identification of components in a gigantic spherical dolomite concretion. It has been found by the MCR and CLS analyses of imaging data that the concretion contains dolomite, kerogen, anatase, quar...

Attenuated total reflection infrared (ATR-IR, 4000–400 cm –1 ), ATR-far-IR (ATR-FIR, 400–50 cm –1 ), and Raman spectra (4000–10 cm –1 ) were measured for calcium carbonate, three kinds of minerals (calcite, aragonite, and quartz), two kinds of rocks (obsidian and pumice), and four kinds of biogenic minerals, i.e., coral (aragonite), Ruditapes phili...

The development of calibration models using Raman spectra data has long been challenged owing to the substantial time and cost required for robust data acquisition. To reduce the number of experiments involving actual incubation, a calibration model development method was investigated by measuring artificially mixed samples. In this method, calibra...

After a brief introduction to the technique, this review will discuss the state-of-the-art NIR imaging instrumentation and its applications, including applications of an ordinary NIR imaging system to solvent diffusion into a polymer. Other imaging applications discussed include the use of a portable NIR imaging system in the pharmaceutical industr...

In this poster presentation, the system configuration and features of this developed FT-IR for broadband measurement are described. Furthermore, we will display the results of one-shot measurement of water spectra in the near- and far-infrared regions and the mid- and far-infrared spectra measured under vacuum conditions to demonstrate the usefulne...

Utilizing X-ray reflectivity and infrared reflection absorption spectroscopy (IR-RAS), we have investigated the thermal expansion and contraction of ultrathin polyvinylphenol (PVPh) films supported on a silicon (100) substrate capped with an amorphous SiO2 layer. Despite being known to form strong interactions with the SiO2 surface, the thin PVPh f...

This study investigated how the secondary structural changes of proteins in aqueous solutions affect their hydration and the hydrogen-bond network of water molecules using near-infrared (NIR) spectroscopy. The aqueous solutions of three types of proteins, i.e., ovalbumin, β-lactoglobulin, and bovine serum albumin, were denatured by heating, and cha...

Micro-Raman spectra of concretions with and without fossils were measured in a nondestructive manner. The band position and full width at half maximum height (FWHM) of ν1-PO4³⁻ of apatite in the concretions were analyzed to investigate the origin of apatite. The analyzed concretions were derived from the Kita-ama Formation of the Izumi Group, Japan...

The characteristic cluster pattern of cross-peaks in a 2D asynchronous spectrum provides an effective way to reveal the specific physicochemical nature of subtle spectral changes caused by intermolecular interactions. However, the inevitable presence of noise in the 1D spectra used to construct a 2D asynchronous spectrum is significantly amplified,...

An apparatus and relevant approach to obtaining IR spectra of solutes from the corresponding aqueous solution were developed. In the experiment, aqueous solutions were converted into aerosols using an ultrasonic or a pneumatic device. Subsequently, water in the nebulized solution is completely gasified under a high-speed flow and low vacuum environ...

In this study, we developed a method to build Raman calibration models without culture data for cell culture monitoring. First, Raman spectra were collected and then analyzed for the signals of all the mentioned analytes: glucose, lactate, glutamine, glutamate, ammonia, antibody, viable cells, media, and feed agent. Using these spectral data, the s...

Surface-enhanced Raman scattering (SERS) and tip-enhanced Raman scattering (TERS) have opened a variety of exciting research fields. However, although a vast number of applications have been proposed since the two techniques were first reported, none has been applied to real practical use. This calls for an update in the recent fundamental and appl...

We proposed a modified and improved approach to removing the interference of moisture from an IR spectrum and the corresponding second derivative spectrum. The temperature fluctuation in the air of the optical path and baseline-drift lead to the small but persistent presence of the interference of moisture. The problem has been successfully address...

This chapter is dedicated to investigation of hydrogen bonding and various manifestations of this phenomenon by near‐infrared (NIR) spectroscopy. This technique offers some benefits for hydrogen bonding studies, as compared with the IR spectroscopy. The free and weakly bonded OH or NH groups are more pronounced in the NIR spectra as compared with b...

This chapter is concerned with ATR‐far‐Ultraviolet (FUV) spectroscopy study of hydrogen bondings. ATR‐FUV spectroscopy is relatively new electronic spectroscopy for condensed phase and allows to investigate electronic states of almost all kinds of molecules. It holds unique advantage for investigating hydrogen bondings and intermolecular interactio...

The objective of this study was to explore intracellular molecular changes during the differentiation of human-induced pluripotent stem cells (iPSCs) into erythropoietin (EPO)-producing cells using Raman spectroscopy and imaging. Raman imaging data of fixed cells at four stages of cell differentiation were analyzed by a partial least squares (PLS)...

Estimation of the stoichiometric ratio of a supramolecular aggregate formed by different compounds is very important in elucidating the structure and function of the aggregate. Many spectroscopic methods used to estimate the stoichiometric ratios of coordination complexes become invalid when characteristic peaks of the aggregate overlap with peaks...

The properties of nanoscale water pools in reverse micelles (RMs) are significantly different from those of bulk water because of the influence of polar groups and spatial confinement. It was commonly accepted that water in RMs exists in two forms: interfacial water near the surfactant polar groups and core water in the central region away from the...

When diffusion coefficients of different components in a mixture are similar, NMR spectra of pure individual components are difficult to be obtained via a diffusion-ordered spectroscopy (DOSY) experiment. Two-dimensional correlation spectroscopy (2D-COS) is used to analyze the data from the DOSY experiment. Through the properties of the systematic...

The overexpression of specific biomarkers in serum is closely related to diseases, and accurate and sensitive detection of them is beneficial for the early diagnosis and treatment of cancer. In this study, we developed a novel surface-enhanced Raman spectroscopy (SERS)-based aptasensor to detect the prostate-specific antigen biomarkers, consisting...

Raman spectra of water and supercooled water were measured in the temperature range of ‐6 to 18°C with every 2°C step. The obtained spectra were analyzed for the 3750‐2850 cm‐1 and 400‐100 cm‐1 regions by two‐dimensional correlation (2D‐COS) Raman spectroscopy. As previously reported, there are three bands at around 3620, 3420, and 3200 cm‐1 in the...

The solvation structures of N-butyl-N-methylpyrrolidinium dicyanamide ([BMP][DCA]) surrounding silver ions were investigated using attenuated total reflectance-ultraviolet (ATR-UV) spectroscopy. The addition of Ag⁺ to [BMP][DCA] red-shifted the [DCA]⁻ absorption band. The shift direction was opposite to that caused by the addition of Li⁺, and these...

We aimed to develop an amino acid sequence-dependent analytical method using near-infrared (NIR) spectroscopy. The detailed analysis of the NIR spectra of eight different amino acid aqueous solutions (glycine, alanine, serine, glutamine, lysine, phenylalanine, tyrosine, and proline) revealed different spectral patterns characteristic of different a...

Raman spectroscopy expands its applications in life science, medicine, pharmacology, agricultural science, and food science, recently. Raman spectroscopy is a strong tool for nondestructive and label free analysis as well as for studies on molecular properties, structures and reactions. The present review introduces the basis and principles of Rama...

Tip-enhanced Raman scattering (TERS) has recently attracted remarkable attention as a novel nano-spectroscopy technique. TERS, which provides site-specific information, can be performed on any material surface regardless of morphology. Moreover, it can be applied in various environments, such as ambient air, ultrahigh vacuum (UHV), solutions, and e...

Visualization of signaling molecules in single living cells is crucial for understanding cellular metabolism and physiology, which can provide valuable insights into early diagnoses and treatments of diseases. Highly sensitive in situ monitoring of intracellular analytes released from single living cells by virtue of label-free nanosensors is urgen...

Inter- and intramolecular hydrogen bondings and their temperature-dependent changes in a poly(4-vinylphenol)/poly(methyl methacrylate)(PVPh30%/PMMA70%) blend were investigated using near-infrared (NIR) and infrared (IR) spectroscopy. Band assignments of the fundamentals and first overtones of the OH stretching mode of a free OH group and OH groups...

In this study, polyvinyl alcohol (PVA) with 88% and 99% degrees of saponification was blended with polymethyl methacrylate (PMMA) to investigate the intramolecular hydrogen bonding in PVA and the intermolecular hydrogen bonding between PVA and PMMA. Differential scanning calorimetry (DSC) results confirmed the miscibility of the PVA/PMMA blends. Te...

This work provides new information on the effect of position and number of substituents on association and solubility of chlorophenols in CCl4. Using MIR and NIR spectroscopy we examined solutions of 12 chlorophenols at several concentrations. In addition, we calculated (DFT) theoretical spectra and structures of monomers and associates of chloroph...

Analysis of mixture via chromatographic-spectroscopic and analogous experiments is a common task in analytical chemistry. A 2D/nD asynchronous spectrum is effective in retrieving spectra of pure substances even if different components cannot be separated. However, noise in the 2D/nD asynchronous spectrum becomes a bottleneck in the analysis. Findin...

Attenuated total reflection-far-ultraviolet (ATR-FUV) spectra in the 145 – 250 nm region were studied for four kinds of proteins (two α-helix rich proteins; bovine serum albumin (BSA) and lysozyme, and two β-sheet rich proteins; concanavalin A and γ-globulin) in different solutions (pure water and phosphate buffered saline (PBS)) with different con...

The demand for Li secondary batteries is increasing, with the need for batteries with a higher level of performance and improved safety features. The use of a highly concentrated aqueous electrolyte solution is an effective way to increase the safety of batteries because it is possible to use "water-in-salt" (WIS) and "hydrate-melt" (HM) electrolyt...

Raman scattering from molecules adsorbed on noble metal surface is enormously enhanced. This phenomenon is called as surface-enhanced Raman scattering (SERS). It has recently been applied to extensively biomedical fields. In this chapter, biomedical sensing for bacteria and biomolecules by SERS are introduced. For bacteria different molecules have...

Food safety have been gaining increasing attention in recent years. For most contaminants, instrumental analysis methods, such as gas/liquid chromatography combined with mass spectroscopy (MS) and inductively coupled plasma-MS, have been established as gold standard methods. However, these methods suffer from several inherent shortcomings, such as...

This review consists of two parts. The first part is concerned with the outline of the spectra analysis methods in NIR spectroscopy. In this part conventional spectra analysis methods such as the analysis based on group frequencies and calculations of difference spectra and second derivatives are explained. The second part describes big efforts of...

Surface-enhanced Raman spectroscopy (SERS) is a highly sensitive technique that enhances the Raman scattering of molecules supported by some nanostructured materials. SERS allows for the structural fingerprinting of low-concentration analytes through the plasmon-mediated amplification of electrical fields or chemical enhancement. Owing to its ultra...

Correlated localized surface plasmon resonance (SPR), surface-enhanced Raman scattering (SERS) and localized electromagnetic (EM) field distributions of pure and modified gold (Au) nanoassemblies have been demonstrated. The Au nanoassemblies were decorated as half-raspberry-like nanostructures by silver (Ag) mists, and the characteristics of their...

Enhancement of the light‐matter coupling is a promising approach to improve the sensitivity and universality of semiconductor‐based surface‐enhanced Raman scattering (SERS). Herein, it is demonstrated that hollow multi‐shelled V2O5 microstructure can be utilized as an active substrate to integrate multiple synergistic contributions. The experiments...

This work provides new insight into assembling and competition between different kinds of interactions for phenol in various solvents. To examine both weak and strong interactions, we selected a series of non-aromatic and aromatic solvents. IR spectra were measured at low (0.05 M) and high (2 M) phenol concentrations. In addition, we calculated (DF...

The significant worldwide expansion of the health food market, which includes functional fruits and vegetables, requires a simple and rapid analytical method for the on-site analysis of functional components, such as carotenoids, in fruits and vegetables, and Raman spectroscopy is a powerful candidate. Herein, we clarified the effects of Raman expo...

Polymer spectroscopy has played a very important role in the investigation of the structure, physical and chemical properties, and reactions of polymers in the last half century. This chapter provides an overview of polymer spectroscopy. It consists of an outline of polymer spectroscopy, a brief history of polymer spectroscopy, an overview of molec...

Near-infrared (NIR) spectra of phenol in a series of non-aromatic and aromatic solvents were recorded to study the competition between various types of solute-solute and solute-solvent interactions. Depending on the phenol concentration, the free OH and OH involved in the OH⋯OH interactions in the dimers and higher associates are present in cyclohe...

An approach is developed to remove the interference of moisture from FTIR spectra. The interference arises from two aspects: the fluctuation on the temperature of the HeNe laser and the fluctuation on the transient concentration of moisture in the light - path of an FTIR spectrometer. The temperature fluctuation on the HeNe laser produces a systema...

Anharmonic quantum chemical calculations were employed to simulate and interpret a near-infrared (NIR) spectrum of caffeine. First and second overtones, as well as binary and ternary combination bands, were obtained, accurately reproducing the lineshape of the experimental spectrum in the region of 10,000–4000 cm⁻¹ (1000–2500 nm). The calculations...

The purpose of this review is to demonstrate advances, challenges and perspectives of quantum chemical approaches in molecular spectroscopy of the condensed phase. Molecular spectroscopy, particularly vibrational spectroscopy and electronic spectroscopy, has been used extensively for a wide range of areas of chemical sciences and materials science...

Tip‐enhanced Raman scattering (TERS) has received significant interest as a new nano‐vibrational spectroscopy technique, which can be used to obtain site‐specific molecular information. TERS instruments have made remarkable progress, and the application of TERS has been expanding to nanomaterials, liquid samples, biological materials, and electroch...

The multivariate curve resolution-alternative least squares (MCR-ALS) algorithm was modified with sample insertion constraint to deconvolute the overlapping peaks in SERS spectra. The developed method was evaluated by the spectral data simulated using a Gaussian distribution function to generate two independent peaks corresponding to a capping agen...

In this study, we have investigated the water absorption-induced structural changes and thermal behavior of ε-poly(L)lysine-hydrochloride (EPLHCl) in the powder and film samples using infrared (IR) and Raman spectroscopy. An X-ray diffraction measurement reveals that the crystal structure of ε-poly(L)lysine (EPL) is similar to that of the γ-crystal...

Total removal of organic mercury in industrial wastewater is a crucially important task facing environmental pollution in the current world. Herein, we demonstrate the fabrication of Au-NiFe layered double hydroxide (LDH)/rGO nanocomposite as not only an efficient nanozyme with oxidase-like activity but also an efficient surface-enhanced Raman spec...

Far-ultraviolet (FUV) spectroscopy in the region of 140–200 nm of condensed-phase has received keen interest as a new electronic spectroscopy. The introduction of the attenuated total reflection (ATR) technique to the FUV region has opened a new avenue for FUV spectroscopy of liquids and solids. ATR-FUV spectroscopy enables the study of electronic...

Ammonium nitrate (AN) is an important component of the chemical industry such as an active ingredient in fertilizers, as an oxidizer in explosive compositions and propellants, and as a blasting agent in civil explosives. Numerous accidents have been reported in the past which concerns its thermal instability and poses a big threat to its processing...

Terbium acetylsalicylate has been prepared, and the ethanol solution of the complex exhibits strong luminescence under the excitation of ultraviolet radiation. When a small amount of bilirubin solution is introduced into the solution containing a high concentration of terbium acetylsalicylate, a remarkable diminution of the luminescence of the terb...

Protein phosphorylation, a post-translational modification of proteins, is of vital importance in biological regulation. Highly sensitive and site-specific identification of phosphorylated proteins is a key requirement for unraveling crucial signal transduction pathways relevant to cancers and neurodegenerative disorders. Traditional detection meth...

This book provides knowledge of the basic theory, spectral analysis methods, chemometrics, instrumentation, and applications of near-infrared (NIR) spectroscopy—not as a handbook but rather as a sourcebook of NIR spectroscopy. Thus, some emphasis is placed on the description of basic knowledge that is important in learning and using NIR spectroscop...

The interfacial charge transfer (CT) that plays an important role in enhancing the photoelectric conversion efficiency of dye-sensitized solar cells (DSSCs) has not always been fully explored. Here, a TiO2@N719@Ag DSSC system was constructed, and the CT processes have been monitored by surface-enhanced Raman scattering (SERS) spectra. Meanwhile, it...

Using near-infrared (NIR) spectroscopy, we aimed to develop a method of monitoring the increasing number of amide bonds with the elongation of the chain length of peptides. Because peptide synthesis can be monitored by evaluating the increasing number of amide bonds with dehydration occurring between amino acids, polyglycine, which has the simplest...

The interactions of acrylic acid-based super absorbent polymers (SAPs) with water and the hydrogen bonding of water within its three-dimensional network were studied using Raman spectroscopy. The Raman spectra of SAP solutions suggested that both the COO⁻ and CH2 groups of SAPs interact with water. The Raman spectra of pure water and those of SAPs...

Previously, we demonstrated that the intensities of cross-peaks in a two-dimensional asynchronous spectrum could be enhanced using sequence change of the corresponding one-dimensional spectra. This unusual approach becomes useful when the determination of the sequential order of physicochemical events is not essential. However, it was not known whe...

Near-infrared (NIR) spectroscopy is a powerful tool in studies of physicochemical properties of various kinds of samples. In particular, NIR spectroscopy contributed considerable to our understanding of intermolecular interactions (e.g. hydrogen bonding), molecular structure, solvent effect, clustering, phase transitions, kinetics. Because of mecha...

This article outlines the recent progress in ultraviolet (UV) spectroscopy in the 140–280 nm region of solid and liquid phases. In this article, we refer to the 120–200 nm region as the far ultraviolet (FUV) region. The word ‘vacuum UV region’ is not appropriate any more at least for the 120–200 nm region because a vacuum evaporation system is not...

This chapter is concerned with the introduction to spectral analysis in the NIR spectroscopy. It consists of two major parts, conventional spectral analysis and spectra pretreatments. In the former, various conventional spectral analysis methods such as group frequency analysis, derivative spectra, difference spectra, spectral analysis based on per...

This chapter describes the principles and characteristics of NIR spectroscopy. It is divided into two subchapters, 2–1. Characteristics and advantages of NIR spectroscopy: In this subchapter some emphasis is put on the versatility of NIR spectroscopy. Some examples of NIR spectra are explained 2–2. Principles of NIR spectroscopy based on quantum me...

It is recently suggested that amyloid polymorphism, i.e., structural diversity of amyloid fibrils, has a deep relationship with pathology. However, its prompt recognition is almost halted due to insufficiency of analytical methods for detecting polymorphism of amyloid fibrils sensitively and quickly. Here, we propose that iodine staining, a histori...

The electronic states of N-butyl-N-methylpyrrolidinium dicyanamide ([BMP][DCA]), a solvated ionic liquid, around Li+ were investigated using attenuated total reflectance far-ultraviolet and deep-ultraviolet (ATR-FUV-DUV) spectroscopy. The absorption bands ascribed to the [DCA]- were blue-shifted as the Li+ concentration increased, and the origin of...

A versatile and robust chiral discrimination strategy for small aromatic compounds is of significant importance in multidisciplinary fields. However, most current methods lack either the sufficient sensitivity for recognizing the chirality of the target molecules or their molecular specificity information. We have developed a versatile and chiral‐l...