Publications by authors named "Iacopo Osticioli"

7 Publications

  • Page 1 of 1

Red lakes from Leonardo's Last Supper and other Old Master Paintings: Micro-Raman spectroscopy of anthraquinone pigments in paint cross-sections.

Spectrochim Acta A Mol Biomol Spectrosc 2019 Nov 13;222:117273. Epub 2019 Jun 13.

Istituto di Nanotecnologie e Fotonica National Research Council (IFN-CNR), Piazza Leonardo da Vinci 32, Milano 20133, Italy; Department of Conservation, University of Gothenburg, Box 130, 40530 Gothenburg, Sweden. Electronic address:

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.
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http://dx.doi.org/10.1016/j.saa.2019.117273DOI Listing
November 2019

Raman spectrometer for the automated scan of large painted surfaces.

Rev Sci Instrum 2019 May;90(5):053101

Institute of Applied Physics "Nello Carrara" (IFAC-CNR), Florence, Italy.

In this work, a novel Raman scanner capable of performing point-to-point mapping of relatively large surface of paintings is presented. This device employs an excitation wavelength of 1064 nm, and it is equipped with a high efficiency probe in order to collect the back-scattered light from each point of analysis. The use of long depth-of-field optics as well as an autofocus system allowed maintaining the best conditions for the Raman signal acquisition during the scanning, regardless of the surface irregularities. The small dimension of the optical components and the reasonable size of mechanical parts made this instrumentation particularly suitable for on-site measurements. Finally, the Raman scanner was also equipped with an online temperature control using a thermal sensor, which allows modulating automatically the output power of the laser source in order to prevent overheating and alteration effects during the scanning process. The capabilities of the Raman scanner were evaluated scanning two valuable paintings one attributed to Ambrogio Lorenzetti and the other to Duccio da Buoninsegna of the fourteenth century.
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http://dx.doi.org/10.1063/1.5088039DOI Listing
May 2019

A remote scanning Raman spectrometer for in situ measurements of works of art.

Rev Sci Instrum 2011 Jun;82(6):063109

Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy.

In conservation science, one of the main concerns is to extract information from an artistic surface without damaging it. Raman spectroscopy has emerged in recent years as a reliable tool for the non-destructive analysis of a wide range of inorganic and organic materials in works of art and archaeological objects. Nevertheless, the technique is still mainly limited to the analysis of micro-samples taken from artistic surfaces. The development of an instrument able to perform non-contact analysis of an area of a few square centimeters aims to further increase the employment of this technique. This paper describes the development of a prototype Raman scanning spectrometer based on a diode laser, a 2D scanning mirror stage and a custom optical system, which can map a surface of 6 cm in diameter at a working distance of 20 cm. The device exhibits collecting optics with a depth of field close to 6 cm, which makes the Raman system suitable for the analysis of non-flat surfaces and three-dimensional objects. In addition, the overall dimensions and weight of the instrument have been limited in order to make the device transportable and, in principle, usable for in situ measurements. Details on the design of the device, with particular emphasis on the collecting optical system, and on results of the characterization tests carried out to assess its performances are reported. Finally, an example of an application involving the identification of pigments from a model painting is presented.
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http://dx.doi.org/10.1063/1.3600565DOI Listing
June 2011

Assessment of the ageing of triterpenoid paint varnishes using fluorescence, Raman and FTIR spectroscopy.

Anal Bioanal Chem 2009 Dec;395(7):2139-49

Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan, Italy.

The assessment of the influence of natural and artificial ageing on the spectrofluorescence of triterpenoid varnishes dammar and mastic is the focus of this work. Both Fourier transform infrared (FTIR) microscopy using attenuated total reflectance and Raman spectroscopy have been employed for complementary molecular analysis of samples. Synchronous fluorescence spectroscopy, excitation emission spectroscopy, and statistical analysis of data have been used to monitor changes in the optical properties of varnish samples. Assessment of naturally and artificially aged samples using excitation emission spectroscopy suggests that extensive exposure to visible light does not lead to easily appreciable differences in the fluorescence of mastic and dammar; cluster analysis has been used to assess changes, which occur with artificial ageing under visible light, indicating that differences in the fluorescence spectra of aged triterpenoids may be insufficient for their discrimination. The results highlight significant differences between the initial fluorescence of films of dammar and mastic and the fluorescence, which develops with ageing and oxidation, and specific markers, which change with ageing in FTIR and Raman spectra, have been identified.
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http://dx.doi.org/10.1007/s00216-009-3005-4DOI Listing
December 2009

An optimization of parameters for application of a laser-induced breakdown spectroscopy microprobe for the analysis of works of art.

Appl Spectrosc 2008 Nov;62(11):1242-9

Department of Chemistry, University of Florence, Polo Scientifico e Tecnologico, via della Lastruccia 3, I-50019, Firenze, Italy.

Laser-induced breakdown spectroscopy (LIBS) provides many advantages for analysis of works of art. Both qualitative and semi-quantitative information about the elemental composition of an object can be rapidly obtained using LIBS. The time of response is on the order of a few seconds and no sample preparation is required. The possibility of performing analysis in museums and archeological sites makes LIBS particularly important; the combination of laser ablation and analysis as encountered in LIBS provides means to effectively carry out depth profiling of samples. By combining the use of a microscope, the dimension of the spot of the laser used to carry out analysis can be reduced and the spatial resolution highly improved; in this way, a very small area of the sample (on the order of 10 miccrom) can be analyzed. The aim of this work is to investigate the best working conditions in order to obtain the least amount of material removal during analysis, and, at the same time, the best quality in the spectral response for rapid and reliable identification of the elemental composition of an object. First, investigations were undertaken using metal alloys; second, the optimized LIBS conditions were used for analysis of models of painting layers prepared in the laboratory. Finally, a painting cross-section and a 19th century painted icon were analyzed using the micro-LIBS setup.
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http://dx.doi.org/10.1366/000370208786401572DOI Listing
November 2008

Shift-excitation Raman difference spectroscopy-difference deconvolution method for the luminescence background rejection from Raman spectra of solid samples.

Appl Spectrosc 2007 Aug;61(8):839-44

University of Florence, Chemistry Department, Polo Scientifico Universitario, Sesto Fiorentino, Italy.

The feasibility of the shift-excitation Raman difference spectroscopy-difference deconvolution (SERDS-DDM) method for fluorescence suppression from Raman spectra of solid samples is discussed. For SERDS measurements a tunable diode laser source with an emission band centered at 684 nm is coupled to a conventional micro-Raman apparatus and a monochromator device is used for checking the excitation frequency stability. The shifted Raman spectra are then mathematically treated and a deconvolution procedure is used to reconstruct the Raman spectrum devoid of fluorescence. Two different cases are presented. In the first one, fluorescence is intrinsic to the sample and the Raman spectrum of cinnabar pigment is finally reconstructed. In the second, the presence of an external luminescence background in the spectrum of a pure sulfur crystal is considered. The SERDS-DDM reconstructed spectra are compared with spectra obtained via multi-point baseline subtraction and a significant improvement in the detection of weak bands is demonstrated. Practical insights for the application of this method are presented as well.
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http://dx.doi.org/10.1366/000370207781540169DOI Listing
August 2007

Raman spectra of proteinaceous materials used in paintings: a multivariate analytical approach for classification and identification.

Anal Chem 2007 Aug 10;79(16):6143-51. Epub 2007 Jul 10.

Department of Chemistry, University of Florence, Polo Scientifico e Tecnologico, via della Lastruccia 3, I-50019, Firenze, Italy.

This work presents Raman spectra obtained from thin films of protein materials which are commonly used as binding media in painted works of art. Spectra were recorded over the spectral range of 3250-250 cm(-1), using an excitation wavelength of 785 nm, and several bands have been identified in the fingerprint region that correspond to the various proteins examined. Differences in the C-H vibrations located between 3200 and 2700 cm(-1) can be accounted for with reference to the amino acid composition of the protein-based binding media as well as the presence of fatty acid esters, in the case of egg yolk. In addition, the discrimination of different proteins on the basis of variations in spectra between 3200 and 2700 cm(-1) can be achieved following multivariate analysis of a large data set of spectra, providing a novel and nondestructive alternative based on Raman spectroscopy to other methods commonly used for the analysis of proteins.
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http://dx.doi.org/10.1021/ac070373jDOI Listing
August 2007