A detachable SERS active cellulose film: a minimally invasive approach to the study of painting lakes

Abstract

The design and synthesis of a tailor-made surface-enhanced Raman scattering (SERS) active film that is fabricated to be removable from the surface of an artwork under study following effective measurements is detailed. It is shown that silver nanoparticles prepared by green chemical reduction with glucose can be effectively doped into a methylcellulose (MC) matrix for the formation of a gel, which can be subsequently applied to a minute area (ca 1-1.5 mm) of an artwork without posing a threat to its integrity. Studies have been aimed at characterizing this film's chemical and physical properties, with regard to the stability of the nanoparticles dispersed within the MC, the ease of application of the viscous gel, its speed of drying and the transparency of the dry film for SERS measurements. Importantly, results have led to reproducible SERS enhancements of the order 10 3 -10 4 for studies carried out on reference laboratory dye components and unvarnished mock-paintings. Techniques including optical and scanning electron microscopy were used to monitor the drying of the film and its resulting morphology, as well as to map the distribution of silver nanoparticles in the film so as to account for any visual modification to the underlying surface upon film removal.

SERS Spectra of Alizarin Anion–Agn (n = 2, 4, 14) Systems: TDDFT Calculation and Comparison with Experiment

“…In recent years many experimental surface enhanced Raman scattering (SERS) spectra of alizarin and its mono-and di-anion species adsorbed on silver nanoparticles have been published [7][8][9][10][11][12][13][14] . DFT theoretical analyses of the vibrational spectroscopic properties of alizarin and its anions were also carried out by limiting the calculation to the bare molecular species [8][9][10]15 .…”

“…Optimized structure of the ionic form of alizarin; hydroxyl in position 1 has been ionizedThe alizarin anion-silver cluster complexes, hereafter AZ anion-Ag n (n=2,4,14), initial geometries have the AZ anion C = O groups in 1, 9 position (seeFig. 1)…”

Tailored micro-extraction method for Raman/SERS detection of indigoids in ancient textiles

“…Moreover, degradation processes or bad state of conservation of the art object may further affect the analyses of the blue dye. In the last decade, the successful application of the high sensitive surface enhanced (resonance) Raman spectroscopy [SE(R)RS] for the detection of organic dyes in works of art has strongly improved the possibility of identifying fluorescent organic dyes according to minimal invasive [10][11][12][13][14] and microdestructive approaches [15][16][17]. Up to the present, the majority of the developed SERS procedures dealt mainly with the detection of red and yellow dyes [15][16][17][18][19][20][21][22][23][24][25][26], whereas only a few works have investigated the characterization of indigoids by means of SERS/SERRS.…”

Raman Spectroscopy of cultural heritage Materials: Overview of Applications and New Frontiers in Instrumentation, Sampling Modalities, and Data Processing

“…To this end, a small but growing number of papers have been published demonstrating the use of flexible substrates based on acrylic gels [182,183], methylcellulose pastes [119], gelatin [120], or agar-agar gel [187,241], optionally loaded with a mild micro-extractant, often based on ethylenediaminetetraacetic acid (EDTA) [240]. The analytical procedure either involves mixing the gel with nanoparticles, or using the gels to extract a minute and nearly invisible amount of dye for later analysis with SERS after deposition of colloidal silver particles on the face that was previously in contact with the artifact.…”