Abstract
Surface-enhanced Raman spectroscopy (SERS) has been identified as a suitable technique for the analysis of colorants in works of art. Herein, the application of SERS to the identification of dye compositions in historical felt-tip pens is reported, which is of paramount importance for the development of appropriate conservation protocols for historical drawings. In this study, three pens (pink, green, and blue colors) belonging to the film director Federico Fellini were analyzed. SERS measurements were performed directly on the pen lines drawn on a commercial paper by the deposition of Ag colloidal pastes, which allowed fast in situ dye identification without the need for extraction or hydrolysis treatments. Eosin Y was identified as the only dye present in the pink pen ink, whereas erioglaucine was found to be the main dye component in green and blue pen inks. SERS also resulted in highly efficient identification of the individual dyes erioglaucine, crystal violet, and rhodamine present as a mixture in the blue pen ink. The high SERS sensitivity was ascribed to the plasmonic effects and efficient quenching of the fluorescence interference of dyes. A comparison with contemporary pen inks highlighted minor differences in the chemical composition. These results prove that SERS can be used as a fast and sensitive analytical tool for ink analysis that provides invaluable support for the general assessment of the date, provenance, and originality of the historical drawings as well as for the development of preventive conservation protocols.
Highlights
Felt-tip pens were introduced in the market in 1953 by Rosenthal and became commonly used by many in uential artists who le a large heritage of artistic productions today hosted by museums all over the world
The plasmonic paste was synthesized according to a method developed by Polavarapu et al.[35] that consisted of reduction of the volume of Ag nanoparticles obtained by the Scheme 1 Schematic of sample preparation for in situ SERS measurements of historical drawings: (a) analytical sample constituted by ink coloured paper; (b) formation of nanopaste by centrifugation of Ag nanoparticle solutions; (c) loading of Ag nanopaste into a microsyringe; (d) droplet deposition of Ag nanopaste on the analytical surface; (e) formation of SERS-active areas on the analytical surface; and (f) SERS measurement
Compared to the standard colloidal solutions used for the analysis of historical dyes and pigments, the high nanoparticle concentration of the developed pastes enabled efficient in situ analysis of water-soluble pen inks
Summary
Felt-tip pens were introduced in the market in 1953 by Rosenthal and became commonly used by many in uential artists who le a large heritage of artistic productions today hosted by museums all over the world. Because of the well-known sensitivity of the inks to light, especially in the UV part of the spectrum, it is currently not known how these artworks will withstand the passage of time.[1,2] In this context, identi cation of dyes constituting felt-tip pen ink mixtures is highly important for the (i) precise assessment of vulnerability, (ii) design of intervention protocols, and (iii) creation of ideal housing and storage conditions for historical drawings and writing materials. Very few studies on the chemical composition of felt-tip pen have been carried out to date. Sodo et al.[3] used
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
