Advanced Vibrational Spectroscopy Research Articles

Advanced Vibrational Spectroscopy and Bacteriophages Team Up: Dynamic Synergy for Medical and Environmental Applications.

Bacteriophages are emerging as a promising alternative in combating antibiotic-resistant bacteria amidst the escalating global antimicrobial resistance crisis. Recently, there has been a notable resurgence of interest in phages, prompting extensive research into their therapeutic potential. Beyond conventional microbiology and virology techniques, such as genomics and proteomics, novel phenotypic and chemical characterization methods are being explored. Among these, there is a growing interest in vibrational spectroscopy, especially in advanced modalities such as surface-enhanced Raman spectroscopy (SERS), tip-enhanced Raman spectroscopy (TERS), and atomic force microscopy-infrared spectroscopy (AFM-IR), which offer improved sensitivity and spatial resolution. This review explores the spectrum of uses of vibrational spectroscopy for bacteriophages, including its role in diagnostics, biosensing, phage detection, assistance in phage-based therapy, and advancing basic research.

Lipid Landscapes: Vibrational Spectroscopy for Decoding Membrane Complexity.

Cell membranes are incredibly complex environments containing hundreds of components. Despite substantial advances in the past decade, fundamental questions related to lipid-lipid interactions and heterogeneity persist. This review explores the complexity of lipid membranes, showcasing recent advances in vibrational spectroscopy to characterize the structure, dynamics, and interactions at the membrane interface. We include an overview of modern techniques such as surface-enhanced infrared spectroscopy as a steady-state technique with single-bilayer sensitivity, two-dimensional sum-frequency generation spectroscopy, and two-dimensional infrared spectroscopy to measure time-evolving structures and dynamics with femtosecond time resolution. Furthermore, we discuss the potential of multiscale molecular dynamics (MD) simulations, focusing on recently developed simulation algorithms, which have emerged as a powerful approach to interpret complex spectra. We highlight the ongoing challenges in studying heterogeneous environments in multicomponent membranes via current vibrational spectroscopic techniques and MD simulations. Overall, this review provides an up-to-date comprehensive overview of the powerful combination of vibrational spectroscopy and simulations, which has great potential to illuminate lipid-lipid, lipid-protein, and lipid-water interactions in the intricate conformational landscape of cell membranes.

Advancing cerumen analysis: exploring innovative vibrational spectroscopy techniques with respect to their potential as new point-of-care diagnostic tools.

Cerumen, commonly known as earwax, is a complex mixture composed of secretions from ceruminous glands. These secretions are heterogeneous mixtures mainly composed of lipids and proteins. Despite its prevalence, the potential diagnostic value of cerumen remains largely unexplored. Here, we present an in-depth analysis of cerumen utilizing well-known vibrational approaches such as conventional Raman spectroscopy or surface-enhanced Raman spectroscopy (SERS) together with advanced vibrational spectroscopy techniques such as coherent Raman scattering (CRS), i.e. broadband coherent anti-Stokes Raman scattering (CARS) or stimulated Raman scattering (SRS), as well as optical photothermal infrared (OPTIR) spectroscopy. Through the integration of these vibrational spectroscopic methods, lipids and proteins can be identified as the main components of cerumen; however, they contribute to the final spectral information to various extents depending on the vibrational detection scheme applied. The inherently weak Raman signal could be enhanced by linear (SERS) and non-linear (CRS) processes, resulting in efficient acquisition of fingerprint information and allowing for the detection of marker modes, which cannot be addressed by conventional Raman spectroscopy. OPTIR spectroscopy provides complementary information to Raman spectroscopy, however, without the contribution of a fluorescence background. Our findings underscore the utility of these cutting-edge techniques in unveiling the intricate molecular landscape of cerumen, paving the way for novel point-of-care diagnostic methodologies and therapeutic interventions.

Application of Advanced Vibrational Spectroscopy in Revealing Critical Chemical Processes and Phenomena of Electrochemical Energy Storage and Conversion.

The future of the energy industry and green transportation critically relies on exploration of high-performance, reliable, low-cost, and environmentally friendly energy storage and conversion materials. Understanding the chemical processes and phenomena involved in electrochemical energy storage and conversion is the premise of a revolutionary materials discovery. In this article, we review the recent advancements of application of state-of-the-art vibrational spectroscopic techniques in unraveling the nature of electrochemical energy, including bulk energy storage, dynamics of liquid electrolytes, interfacial processes, etc. Technique-wise, the review covers a wide range of spectroscopic methods, including classic vibrational spectroscopy (direct infrared absorption and Raman scattering), external field enhanced spectroscopy (surface enhanced Raman and IR, tip enhanced Raman, and near-field IR), and two-photon techniques (2D infrared absorption, stimulated Raman, and vibrational sum frequency generation). Finally, we provide perspectives on future directions in refining vibrational spectroscopy to contribute to the research frontier of electrochemical energy storage and conversion.

Applications of Vibrational Spectroscopy for Analysis of Connective Tissues.

Advances in vibrational spectroscopy have propelled new insights into the molecular composition and structure of biological tissues. In this review, we discuss common modalities and techniques of vibrational spectroscopy, and present key examples to illustrate how they have been applied to enrich the assessment of connective tissues. In particular, we focus on applications of Fourier transform infrared (FTIR), near infrared (NIR) and Raman spectroscopy to assess cartilage and bone properties. We present strengths and limitations of each approach and discuss how the combination of spectrometers with microscopes (hyperspectral imaging) and fiber optic probes have greatly advanced their biomedical applications. We show how these modalities may be used to evaluate virtually any type of sample (ex vivo, in situ or in vivo) and how “spectral fingerprints” can be interpreted to quantify outcomes related to tissue composition and quality. We highlight the unparalleled advantage of vibrational spectroscopy as a label-free and often nondestructive approach to assess properties of the extracellular matrix (ECM) associated with normal, developing, aging, pathological and treated tissues. We believe this review will assist readers not only in better understanding applications of FTIR, NIR and Raman spectroscopy, but also in implementing these approaches for their own research projects.

Recent advances in linear and nonlinear Raman spectroscopy. Part XIII

AbstractThis article is an overview of advances in Raman spectroscopy published in 2018 in the Journal of Raman Spectroscopy (JRS) and, in addition, trends over the past decade across journals that have published papers important to the field of Raman spectroscopy. The trends are based on statistical data of article counts obtained from Clarivate Analytic's Web of Science Core Collection by year and by subfield of Raman spectroscopy. Coverage is provided for presentations involving Raman spectroscopy at four international conferences this year: the Tenth International Conference on Advanced Vibrational Spectroscopy (ICAVS‐10) in Aukland, New Zealand in July; SCIX 2019 organized by the Federation of Analytical Chemistry and Spectroscopy Societies (FACSS) in Palm Springs, California USA in October; the European Conference on Nonlinear Optical Spectroscopy (ECONOS 2019) in Rouen, France in April; and the Tenth International Congress on the Application of Raman Spectroscopy in Art and Archaeology (RAA 2019) in Potsdam, Germany in September. Finally, papers published in JRS in 2018 are highlighted and arragned by topics at the frontier of Raman spectroscopy. Based on these data, presentations, and publications, it is clear that Raman spectroscopy continues as an expanding field of research across a wide range of novel disciplines and applications that provide sensitive photonic information at the molecular level.

Advances in vibrational spectroscopy provide new ways for characterizing semiconductor impurities

Improvements in computing push the boundaries of vibrational spectroscopy, allowing for observation of new electronic properties of semiconductors with light-mass element impurities.

Recent advances in linear and non‐linear Raman spectroscopy. Part XI

AbstractThis review, published annually, provides an overview of advances in the field of Raman spectroscopy as found in papers published in the preceding calendar year in the Journal of Raman Spectroscopy (JRS), as well as in trends over the past decade across journals that have published papers important to the field of Raman spectroscopy. This information is obtained from statistical data on article counts obtained from Clarivate Analytics' Web of Science Core Collection by year and by subfield of Raman spectroscopy. Additional information is gleaned from presentations at the IX International Conference on Advanced Vibrational Spectroscopy (ICAVS‐9) in Victoria, British Columbia, Canada, in June 2017 and those featuring Raman scattering at SCIX 2017 organized by the Federation of Analytical Chemistry and Spectroscopy Societies (FACSS) in Reno, Nevada, USA, in October 2017. Coverage is also provided for topics from the European Conference on Non‐linear Optical Spectroscopy (ECONOS 2017) held in April 2017 in Jena, Germany, and the Ninth Congress on the Application of Raman in Art and Archaeology (RAA 2017) in October 2017 in Evora, Portugal. Finally, papers published in JRS in 2016 are highlighted and arranged by topics at the frontier of Raman spectroscopy. Based on this survey information, it is clear that Raman spectroscopy maintains a rapidly expanding influence across a wide range of novel disciplines and applications that provide sensitive photonic information of matter at the molecular level.

C-Terminal Truncated α-Synuclein Fibrils Contain Strongly Twisted β-Sheets.

C-terminal truncations of monomeric wild-type alpha-synuclein (henceforth WT-αS) have been shown to enhance the formation of amyloid aggregates both in vivo and in vitro and have been associated with accelerated progression of Parkinson’s disease (PD). The correlation with PD may not solely be a result of faster aggregation, but also of which fibril polymorphs are preferentially formed when the C-terminal residues are deleted. Considering that different polymorphs are known to result in distinct pathologies, it is important to understand how these truncations affect the organization of αS into fibrils. Here we present high-resolution microscopy and advanced vibrational spectroscopy studies that indicate that the C-terminal truncation variant of αS, lacking residues 109–140 (henceforth referred to as 1–108-αS), forms amyloid fibrils with a distinct structure and morphology. The 1–108-αS fibrils have a unique negative circular dichroism band at ∼230 nm, a feature that differs from the canonical ∼218 nm band usually observed for amyloid fibrils. We show evidence that 1–108-αS fibrils consist of strongly twisted β-sheets with an increased inter-β-sheet distance and a higher solvent exposure than WT-αS fibrils, which is also indicated by the pronounced differences in the 1D-IR (FTIR), 2D-IR, and vibrational circular dichroism spectra. As a result of their distinct β-sheet structure, 1–108-αS fibrils resist incorporation of WT-αS monomers.

Translating vibrational spectroscopy into clinical applications - vision or reality?

The Faraday Discussion meeting "Advanced Vibrational Spectroscopy for Biomedical Applications" provided an excellent opportunity to share and discuss recent research and applications on a highly interdisciplinary level. Spectral pathology, single cell analysis, data handling, clinical spectroscopy, and the spectral analysis of biofluids were among the topics covered during the meeting. The focus on discussion rather than "merely" presentation was highly appreciated and fruitful discussions evolved around the interpretation of the amide-bands, optical resolution, the role of diffraction and data analysis procedure, to name a few. The meeting made clear that the spectroscopy of molecular vibrations in biomolecules has evolved from a purely academic research tool to a technology used in clinical practice in some cases. In this sense, biomedical vibrational spectroscopy has reached a pivotal point at which questions like diagnostic value, therapeutic consequence and financial viability are gaining more and more importance.

Recent advances in linear and non‐linear Raman spectroscopy. Part IX

This annual review is published to provide an overview of advances in the field of Raman spectroscopy as reflected in papers published each year in the Journal of Raman Spectroscopy (JRS) as well as in trends across related journals that have published papers in the broad field of Raman spectroscopy. The content is obtained from statistical data on article counts obtained from Thomson Reuters ISI Web of Science Core Collection by year and by subfield of Raman spectroscopy. Additional information is gleaned from presentations at the VIII International Conference on Advanced Vibrational Spectroscopy (ICAVS‐8) in Vienna, Austria in July 2015 and those featuring Raman scattering at SCIX 2015 organized by the Federation of Analytical Chemistry and Spectroscopy Societies (FACSS) in Providence, Rhode Island, USA, in September/October 2015. Coverage is also provided for topics from the conference ECONOS 2015 held in April in Leuven, Belgium. Finally, papers published in JRS in 2014 are highlighted and arranged by topics at the frontier of Raman spectroscopy. Taken from these various viewpoints, it is clear that Raman spectroscopy continues to be a rapidly expanding field that provides sensitive photonic information of matter at the molecular level in an ever‐widening arena of novel applications. Copyright © 2015 John Wiley & Sons, Ltd.

Molecular spectroscopy from near-infrared to terahertz wavelengths—more than just good vibrations: Seventh International Conference on Advanced Vibrational Spectroscopy (ICVAS 7)

Aims and topics Vibrational spectroscopy is often the first and last method of an analytical chain. Recent developments in optics, lasers, detectors, and nanotechnology have led to a substantial broadening of the spectrum of methods available for many applications in fields ranging from chemistry to materials science to medicine. These developments were recently highlighted at the Seventh International Conference on Advanced Vibrational Spectroscopy (ICVAS 7), which was held from August 25th to 30th in Kobe, Japan (Fig. 1). The aims of this conference were to address current directions of research into vibrational spectroscopy, to report recent developments in this field, and to discuss practical applications of vibrational spectroscopy.

Biochemical and molecular aspects of spectral diagnosis in calcinosis cutis

Calcinosis cutis (CC) is a type of calcinosis wherein insoluble compounds or salts deposited on the skin. Clinical diagnosis of CC is usually achieved through time consuming histopathological or immunohistochemical procedures, but it can only be empirically identified by experienced practitioners. The use of advanced vibrational spectroscopy has been recently shown to have great potential as a diagnostic technique for various diseased tissues because it analyses the chemical composition of diseased tissue rather than its anatomy and predicts disease progression. This review article includes a summary of the application of Fourier transform infrared (FT-IR) and Raman spectroscopic or microspectroscopic analysis for the rapid diagnosis and identification of the chemical composition of skin calcified deposits in patients with various CC symptoms. Both advanced techniques not only can detect the types of insoluble salts such as calcium phosphate, calcium carbonate, and monosodium urate, and β-carotene in the calcified deposits of human skin tissue but also can directly differentiate the carbonate substitution in the apatite structure of the skin calcified deposits. In particular, the combination of both vibrational techniques may provide complementary information to simultaneously assess the intact components of the calcified deposits. In the future, both FT-IR and Raman vibrational microspectroscopic techniques will become available tools to support the standard test techniques currently used in some clinical diagnoses. Molecular spectroscopy technique is rapidly changing disease diagnosis and management.

The Seventh International Conference of Advanced Vibrational Spectroscopy (ICAVS-7)

The Seventh International Conference of Advanced Vibrational Spectroscopy (ICAVS-7)

Recent advances in linear and nonlinear Raman spectroscopy. Part VII

The aim of this paper is to provide an overview of advances in the field of Raman spectroscopy as reflected in articles published each year in the Journal of Raman Spectroscopy as well as in trends across related journals publishing in this research area. The context for this review is derived from statistical data on article counts obtained from Thomson Reuters ISI Web of Knowledge by year and by subfield of Raman spectroscopy. Additional information is gleaned from presentations featuring Raman spectroscopy presented at the International Conference on Advanced Vibrational Spectroscopy in Kobe Japan in August 2013 and at SCIX 2013 sponsored by the Federation of Analytical Chemistry and Spectroscopy Societies in Milwaukee, Wisconsin, USA, October 2013. Papers published in the Journal of Raman Spectroscopy in 2012 are highlighted in this review and reflect topics and advances at the frontier of Raman spectroscopy, a field that is expanding rapidly as a sensitive photonic probe of matter at the molecular level in an ever widening sphere of novel applications. Copyright © 2013 John Wiley & Sons, Ltd.

146 Amyloid fibril polymorphism probed by advanced vibrational spectroscopy

Amyloid fibrils are associated with many neurodegenerative diseases. All known amyloids including pathogenic and nonpathogenic forms display functional and structural heterogeneity (polymorphism) which determines the level of their toxicity. Despite a significant biological and biomedical importance, the nature of the amyloid fibril polymorphism remains elusive. We utilized for the first time three most advanced vibrational techniques to probe the core, the surface, and supramolecular chirality of fibril polymorphs. A new type of folding, aggregation phenomenon, spontaneous refolding from one polymorph to another, was discovered (Kurouski, Lauro et al., 2010). Hydrogen–deuterium exchange deep UV resonance Raman spectroscopy (Oladepo, Xiong et al., 2012) combined with advanced statistical analysis (Shashilov & Lednev, 2010) allowed for structural characterization of the highly ordered cross-β core of amyloid fibrils. We reported several examples showing significant variations in the core structure for fibril polymorphs. Amyloid fibrils are generally composed of several protofibrils and may adopt variable morphologies, such as twisted ribbons or flat-like sheets. We discovered the existence of another level of amyloid polymorphism, namely, that associated with fibril supramolecular chirality. Two chiral polymorphs of insulin, which can be controllably grown by means of small pH variations, exhibit opposite signs of vibrational circular dichroism (VCD) spectra (Kurouski, Dukor et al. 2012). VCD supramolecular chirality is correlated not only by the apparent fibril handedness but also by the sense of supramolecular chirality from a deeper level of chiral organization at the protofilament level of fibril structure. A small pH change initiates spontaneous transformation of insulin fibrils from one polymorph to another. As a result, fibril supramolecular chirality overturns both accompanying morphological and structural changes (Kurouski, Dukor et al. 2012). No conventional methods could probe the fibril surface despite its significant role in the biological activity. We utilized tip-enhanced Raman spectroscopy (TERS) to characterize the surface structure of an individual fibril due to a high depth and lateral spatial resolution of the method in the nanometer range (Kurouski, Deckert-Gaudig et al. 2012). It was found that the surface is strongly heterogeneous and consists of clusters with various protein conformations and amino acid composition.

Organic Constituents on the Surfaces of Aerosol Particles from Southern Finland, Amazonia, and California Studied by Vibrational Sum Frequency Generation

This article summarizes and compares the analysis of the surfaces of natural aerosol particles from three different forest environments by vibrational sum frequency generation. The experiments were carried out directly on filter and impactor substrates, without the need for sample preconcentration, manipulation, or destruction. We discuss the important first steps leading to secondary organic aerosol (SOA) particle nucleation and growth from terpene oxidation by showing that, as viewed by coherent vibrational spectroscopy, the chemical composition of the surface region of aerosol particles having sizes of 1 μm and lower appears to be close to size-invariant. We also discuss the concept of molecular chirality as a chemical marker that could be useful for quantifying how chemical constituents in the SOA gas phase and the SOA particle phase are related in time. Finally, we describe how the combination of multiple disciplines, such as aerosol science, advanced vibrational spectroscopy, meteorology, and chemistry can be highly informative when studying particles collected during atmospheric chemistry field campaigns, such as those carried out during HUMPPA-COPEC-2010, AMAZE-08, or BEARPEX-2009, and when they are compared to results from synthetic model systems such as particles from the Harvard Environmental Chamber (HEC). Discussions regarding the future of SOA chemical analysis approaches are given in the context of providing a path toward detailed spectroscopic assignments of SOA particle precursors and constituents and to fast-forward, in terms of mechanistic studies, through the SOA particle formation process.

Determination of Antioxidant Content and Antioxidant Activity in Foods using Infrared Spectroscopy and Chemometrics: A Review

Developing rapid analytical methods for bioactive components and predicting both the concentration and biological availability of nutraceutical components in foods is a topic of growing interest. Here, analysis of bioactive components and total antioxidant activity in food matrices using infrared spectroscopy coupled with chemometric predictive models is described. Infrared spectroscopy offers an alternative to wet chemistry, chromatographic determination of antioxidants, and in vitro biochemical assays for assessment of antioxidant activity. Spectroscopic methods provide a technique that can be used with biological tissues without extraction, which can often lead to degradation of the antioxidant components. Sample preparation time greatly decreases and analysis time is very short once a predictive model has been developed. Spectroscopic methods can have a high degree of precision when applied to analysis of nutraceutical compound concentration and antioxidant activity in foods. This article summarizes recent advances in vibrational spectroscopy and chemometrics and applications of these methods for antioxidant detection in foods.

Recent advances in linear and nonlinear Raman spectroscopy. Part V

The purpose of the review is to provide a concise overview of recent advances in the broadly defined field of Raman spectroscopy as reflected in part by the many articles published each year in JRS as well as in trends across all related journals publishing in this research area. Context for this review is derived from statistical data on article counts obtained from Thomson Reuters ISI Web of Knowledge by year and by subfield of Raman spectroscopy. Additional information is gleaned from presentations featuring Raman spectroscopy presented at the meetings of the Federation of Analytical Chemistry and Spectroscopy Societies 2011 and the Sixth International Conference on Advanced Vibrational Spectroscopy 2011. Papers published in JRS in 2010, as reviewed here, reflect trends at the cutting edge of Raman spectroscopy, which is expanding rapidly as a sensitive photonic probe of matter at the molecular level with an ever‐widening sphere of novel applications. Copyright © 2011 John Wiley & Sons, Ltd.

Vibrational Spectroscopy of Water at Interfaces

Understanding liquid water's behavior at the molecular level is essential to progress in fields as disparate as biology and atmospheric sciences. Moreover, the properties of water in bulk and water at interfaces can be very different, making the study of the hydrogen-bonding networks therein very important. With recent experimental advances in vibrational spectroscopy, such as ultrafast pulses and heterodyne detection, it is now possible to probe the structure and dynamics of bulk and interfacial water in unprecedented detail. We consider here three aqueous interfaces: the water liquid-vapor interface, the interface between water and the surfactant headgroups of reverse micelles, and the interface between water and the lipid headgroups of aligned multi-bilayers. In the first case, sum-frequency spectroscopy is used to probe the interface. In the second and third cases, the confined water pools are sufficiently small that techniques of bulk spectroscopy (such as FTIR, pump-probe, two-dimensional IR, and the like) can be used to probe the interfacial water. In this Account, we discuss our attempts to model these three systems and interpret the existing experiments. For the water liquid-vapor interface, we find that three-body interactions are essential for reproducing the experimental sum-frequency spectrum, and presumably for the structure of the interface as well. The observed spectrum is interpreted as arising from overlapping and canceling positive and negative contributions from molecules in different hydrogen-bonding environments. For the reverse micelles, our theoretical models confirm that the experimentally observed blue shift of the water OD stretch (for dilute HOD in H(2)O) arises from weaker hydrogen bonding to sulfonate oxygens. We interpret the observed slow-down in water rotational dynamics as arising from curvature-induced frustration. For the water confined between lipid bilayers, our theoretical models confirm that the experimentally observed red shift of the water OD stretch arises from stronger hydrogen bonding to phosphate oxygens. We develop a model for heterogeneous vibrational lifetime distributions, and we implement the model to calculate isotropic and anisotropic pump-probe decays. We then compare these results with experimental data. Clearly, recent experimental advances in vibrational spectroscopy have led to beautiful new results, providing information about the structure and dynamics of water at interfaces. These experimental and concomitant theoretical advances (particularly the unified theoretical framework of non-linear response functions) have greatly contributed to our understanding of this unique and important substance.