There is a requirement for a noninvasive technique to monitor stem cell differentiation. Several candidates based on optical spectroscopy are discussed in this review: Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and coherent anti-Stokes Raman scattering (CARS) microscopy. These techniques are briefly described, and the ability of each to distinguish undifferentiated from...

Over last 25 years, lignin applications of Raman spectroscopy have come a long way. This article provides a brief overview of the advances in the field of lignin. The paper heavily draws on author’s own research although where appropriate examples are included from published work of other researchers. It is emphasized that the developments in Raman instrumentation along with applications of var...

Quantitative characterization of atherosclerotic plaque composition with standard histopathological methods remains limited to sectioned plaques. Raman spectroscopy enables nondestructive quantification of atherosclerotic plaque composition. We used Raman spectroscopy to study the effects of diet and lipid-lowering therapy on plaque development in apolipoprotein (APO) E*3-Leiden transgenic mice...

Identifying the mechanism of action of new potential antibiotics is a necessary but time-consuming and costly process. Phenotypic profiling has been utilized effectively to facilitate the discovery of the mechanism of action and molecular targets of uncharacterized drugs. In this research, Raman spectroscopy was used to profile the phenotypic response of Escherichia coli to applied antibiotics....

Investigating carbonaceous microstructures and material in Earth's oldest sedimentary rocks is an essential part of tracing the origins of life on our planet; furthermore, it is important for developing techniques to search for traces of life on other planets, for example, Mars. NASA and ESA are considering the adoption of miniaturized Raman spectrometers for inclusion in suites of analytical i...

Unlike other CARS-based (coherent anti-Stokes Raman scattering) spectroscopy techniques, nonlinear interferometric vibrational spectroscopy (NIVS) is linear in analyte concentration and has a Raman line shape free of nonresonant background distortions. We use spontaneous Raman scattering as a high accuracy benchmark for NIVS. As a challenging comparison, we examine spectra in the CH stretching ...

Potentiostatic, galvanostatic and cyclic potentiodynamic depositions of polyaniline were studied by cyclic voltammetry and in-situ Raman spectroscopy. Multivariate analysis of the spectroelectrochemical data including evolving factor analysis, multivariate curve resolution and 2Dcorrelation spectroscopy was applied to resolve overlapped bands in Raman spectra and to assign them reliably. Oxidiz...

Melanins are the most prevalent pigments in animals and are involved in visual communication by producing colored traits that often evolve as intraspecific signals of quality. Identifying and quantifying melanins are therefore essential to understand the function and evolution of melanin-based signals. However, the analysis of melanins is difficult due to their insolubility and the lack of simp...

We demonstrate coherent Raman spectroscopy (CRS) using a tunable excitation source based on a single femtosecond fiber laser. The frequency difference between the pump and the Stokes pulses was generated by soliton self-frequency shifting in a nonlinear optical fiber. Spectra of C─H stretches of cyclohexane were measured simultaneously by stimulated Raman gain (SRG) and coherent anti-Stokes Ram...

Recent results of Raman spectroscopy studies of lattice dynamics and phase transitions in ferroelectric thin films and superlattices are reviewed. Raman studies of SrTiO3, BaTiO3, and BaxSr1−xTiO3 thin films in comparison to corresponding single crystals are presented; essential differences in the lattice dynamics behavior of thin films and single crystals are discussed. Application of ultravio...