Plasma-wall interaction in magnetic fusion devices is responsible for wall changes and plasma pollution with major safety issues. It is investigated both in situ and ex situ, especially by realizing large scale dedicated post-mortem campaigns. Selected parts of the walls are extracted and characterized by several techniques. It is important to extract hydrogen isotopes, oxygen or other element content. This is classically done by ion beam analysis and thermal desorption spectroscopy. Raman microscopy is an alternative and complementary technique. The aim of this work is to demonstrate that Raman microscopy is a very sensitive tool. Moreover, if coupled to other techniques and tested on wellcontrolled reference samples, Raman microscopy can be used efficiently for characterization of wall samples. Present work reviews long experience gained on carbon-based materials demonstrating how Raman microscopy can be related to structural disorder and hydrogen retention, as it is a direct probe of chemical bonds and atomic structure. In particular, we highlight the fact that Raman microscopy can be used to estimate the hydrogen content and bonds to other elements as well as how it evolves under heating. We also present state-of-the-art Raman analyses of beryllium- and tungsten-based materials, and finally, we draw some perspectives regarding boron-based deposits.

The identification of colorants in historic plastics is a methodological and analytical challenge. Although deformulation is performed by the plastics industry, in the case of historical objects, sampling is often impossible, and in situ protocols are needed. The accurate identification of colorants provides insights into historical plastic formulations, supports planning of conservation studies, and critical data for objects that already exhibit color change (e.g. fading). Indeed, colorants may degrade following exposure to light, and color changes have been reported for plastic objects. The analysis of colorants remains a challenge, and microsampling is usually required. Successful identification of red pigments from thirty historical plastics is reported following a new in situ analytical protocol based on Raman microscopy. Information about other pigments, fillers and plastic polymers are reported. Fading has been observed in the historical plastic objects containing Pigment Red 53.

Colorants are present in trace concentration in objects made of plastic and their identification is a methodological and analytical challenge. In conservation, the identification of colorants may allow a better understanding of colorant degradation (such as color change and fading) and provide information about the historical development, production and processing of plastics(.) Although micro-destructive analytical protocols are well established for the analysis of colorants, in cultural heritage, where in situ methodologies are preferred and, in some cases, mandatory, new approaches are greatly needed. In this work, an in situ multi-analytical approach is used to specifically study inorganic cadmium-based pigments that were commonly used for coloring plastics during the 20th c. First introduced as vivid artists' pigments, cadmium-based additives were used for coloring plastics because of their exceptional performance properties. Eighteen colored polymethyl methacrylate (PMMA) samples, produced in the second half of the 20th c. by the company Plasticos do Sado (Portugal), were studied with a combination of optical microscopy, colorimetry, UV-Vis-NIR diffuse reflectance, laser-induced photo-luminescence, vibrational (t-Raman) and elemental (t-EDXRF) spectroscopies. On the basis of complementary data, the chemical composition of most of the coloring agents employed in the acrylic samples were identified without any micro-sampling.

Tissue morpho-mechanics is gaining an increasing relevance in various fields, including biology, medicine, pathology, tissue engineering, and regenerative medicine, since it targets the relationship between morphological features and mechanical properties in biological tissues, which plays an important role in various biological processes including metastasis, wound healing and tissue regeneration. In particular, in every biological tissue, morphological, biochemical and mechanical properties are tightly connected and they influence each other in a correlative manner. For this reason, a correlative approach employing multiple techniques is ideal for targeting tissue morpho-mechanics with an optical approach. Here we report a correlative study performed by optical microscopies, disclosing the supramolecular collagen morphology correlated with its biomechanical and biochemical analyses. In particular, using human corneal tissue as a benchmark, we correlate Second-Harmonic Generation maps with mechanical and biochemical imaging obtained by Brillouin and Raman micro-spectroscopy, demonstrating that the peculiar mechanical functionality of so-called sutural lamellae originates from their distinctive supramolecular organization. A theoretical model based on the ultrastructural symmetry of corneal lamellar domains provides the interpretation of the experimental data at the molecular scale. The proposed methodology opens the way to the non-invasive assessment of tissue morpho-mechanics and holds the potential to be applicable to a broad range of biological and synthetic materials.

The analysis of red particles in paint cross-sections from Leonardo da Vinci's Last Supper, Masolino da Panicale's wall painting Beheading of St. John the Baptist in Castiglione Olona, Tintoretto's The Discovery of the Body of Saint Mark and Paolo Veronese's Supper in the House of Simon has been carried out with micro-Raman measurements. Subtracted shifted Raman spectroscopy methods have been employed to resolve the signals in the presence of fluorescence. Taking advantage of the vibrational assignments based on recent ab initio calculations of aluminum-complexes of anthraquinones, the approach allowed the discriminate between anthraquinone dyes and lakes based on kermesic and carminic acids present in the studied samples for the first time without heavy sample treatment.

Surface functionalization is a key step in biosensing since it is the basis of an effective analyte recognition. Among all the bioreceptors, antibodies (Abs) play a key role thanks to their superior specificity, although the available immobilization strategies suffer from several drawbacks. When gold is the interacting surface, the recently introduced Photochemical Immobilization Technique (PIT) has been shown to be a quick, easy-to-use and very effective method to tether Abs oriented upright by means of thiols produced via tryptophan mediated disulphide bridge reduction. Although the molecular mechanism of this process is quite well identified, the detailed morphology of the immobilized antibodies is still elusive due to inherent difficulties related to the microscopy imaging of Abs. The combination of Mass Spectrometry, Surface-Enhanced Raman Spectroscopy and Ellman's assay demonstrates that Abs irradiated under the conditions in which PIT is realized show only two effective disulphide bridges available for binding. They are located in the constant region of the immunoglobulin light chain so that the most likely position Ab assumes is side-on, i.e. with one Fab (i.e. the antigen binding portion of the antibody) exposed to the solution. This is not a limitation of the recognition efficiency in view of the intrinsic flexibility of the Ab structure, which makes the free Fab able to sway in the solution, a feature of great importance in many biosensing applications.

In this work, GdSr2RuCu2O8-delta (Gd1212) superconductor-based melt-textured pellets in the normal state were analyzed by means of the Raman Microscopy. The Raman spectroscopy and microscopy provided a structuralmapping of our Gd1212 samples, allowing us to distinguish superconducting matrix from nonsuperconducting phases inclusions (precipitates) and providing an instrument to discriminate among optical responses of the different compounds. Specifically, the Raman characterization revealed the presence of two different precipitates instead of the expected one, suggesting that more phases may be involved in the melting-resolidification process than what was presumed.

Raman spectroscopy and digital holography as multimodal approach to cells discrimination and imaging

Extra virgin (EV) olive oil has been characterized by means of micro-Raman spectroscopy. In order to overcome the natural fluorescence of oil a seed layer of Au nanoparticles (GNP) has been used on the top of microscope glass substrates that hosts the liquid sample during the measurement. This method enhances the Raman signal with respect to fluorescence and allows to obtain a deep insight on the chemical and structural state of the sample.

In this work polymorphs of alpha-aminobenzylpenicillin (ampicillin), a beta-lactamic antibiotic, were prepared and investigated by several experimental and theoretical methods. Amorphous monohydrate and three crystalline forms, the trihydrate, the crystal form I and the crystal form II, were investigated by FT-IR and micro-Raman. Also data obtained by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray powder diffraction (XRPD) and hot-stage Raman spectroscopy are reported. Finally, quantum mechanical calculations were performed by density functional theory (DFT) to assist the assignment of spectroscopic experimental bands. For the first time, the ampicillin molecule in its zwitterionic form was studied at the B3LYP/aug-cc-pVDZ level and the corresponding theoretical vibrational spectra were computed. In fact, ampicillin in the crystal is in zwitterionic form and concentrations of this same form are quite relevant in solutions at physiological pH. Experimental and theoretical results allowed identification of specific features for polymorph characterization. Bands typical of the different polymorphs are identified both in IR and Raman spectra: in particular in the NH stretching region (IR), in the amide I + delta NH region (both techniques), in the 1520-1490 cm(-1) region (IR), in the 1320-1300 cm(-1) and 1280-1220 cm(-1) (IR), in the 1200-1170 cm(-1) (Raman), in the amide V region (IR), and, finally, in the 715-640 cm(-1) and 220-200 cm(-1) (Raman). Interconversion among different polymorphs was investigated by hot-stage Raman spectroscopy and thermal analysis, clarifying the complex pattern of transformations undergone as a function of temperature and heating rate. In particular, DSC scans show how the trihydrate crystals transform into anhydrous forms on heating. Finally, stability tests demonstrated, after a two years period, that no transformation or degradation of the polymorphs occurred. (C) 2014 Elsevier B.V. All rights reserved.

The results of the quantitative Raman analysis, performed on multi-walled carbon nanotubes produced by iron-catalysed chemical vapour deposition, are utilised for deriving a scaling law for the growth parameters. A semi-empirical approach, already successfully applied to different materials and growth techniques, is utilised and demonstration is given that the reaction outcome, in terms of yield to C deposits and crystalline perfection of nanotubes attained, analytically depends on the growth parameters through a single dimensionless combination of them.