On the identification of folium by SERS: from crude extracts to illuminated codices. (29th December 2016)

• Record Type: Journal Article
• Authors: Aceto, Maurizio; Calà, Elisa; Arrais, Aldo; Clericuzio, Marco; Marsano, Francesco; Idone, Ambra; Davit, Patrizia; Menghini, Luigi; Gulmini, Monica
• Is Part Of: Journal of Raman spectroscopy. Volume 48:Number 4(2017)
• Page Start: 530
• Page End: 537
• Publication Date: 2016-12-29
• Subjects: SERS -- folium -- Chrozophora tinctoria -- illuminated manuscripts; Raman spectroscopy -- Periodicals; 535.846
• DOI: 10.1002/jrs.5072
• Languages: English
• ISSNs: 0377-0486

Abstract

Abstract : The ancient purple dye known as folium is still a mystery for both scientists and art historians. Today, it is commonly assumed that folium was produced from the fruits of Chrozophora tinctoria (L.) A. Juss., a plant belonging to the Euphorbiaceae family, and efforts have been mainly devoted to highlight the analytical features of the dyes extracted from this plant, whereas detection in ancient manuscripts has been mainly based on poorly selective, non‐invasive analytical techniques. As a consequence, the possibility that the actual source for the dye could have been so far misunderstood cannot be excluded. Surface‐enhanced Raman spectroscopy (SERS), a highly selective and sensitive analytical technique, has been used here to characterize both extracts from C. tinctoria and a microsample taken from a medieval manuscript. The behaviour of the dyes as SERS probes has been investigated in order to set up an accurate and selective procedure for the identification of the dye in ancient artworks. By unambiguously detecting the dye by SERS in the microsample of the medieval manuscript, we also demonstrated that the purple dye mentioned in ancient treatises is definitely linked with the aqueous extract from purple fruits of C. tinctoria . Copyright © 2016 John Wiley & Sons, Ltd. Abstract : The ancient purple dye known as folium, produced from fruits of Chrozophora tinctoria (L.) A. Juss., is still a mystery for scientists and art historians. Surface Enhanced Raman Spectroscopy (SERS) has been used to characterize extracts from C. tinctoria and a micro‐sample taken from a 14th century manuscript. The behaviour of the dyes as probes for SERS has been investigated, in order to set up an accurate and selective procedure for the identification of the dye in ancient artworks.