Identification of anthocyanins in plant sources and textiles by surface‐enhanced Raman spectroscopy (SERS). (11th September 2015)

• Record Type: Journal Article
• Authors: Zaffino, Chiara; Bruni, Silvia; Russo, Bianca; Pilu, Roberto; Lago, Chiara; Colonna, Gian Maria
• Is Part Of: Journal of Raman spectroscopy. Volume 47:Number 3(2016)
• Page Start: 269
• Page End: 276
• Publication Date: 2015-09-11
• Subjects: SERS -- anthocyanins -- art -- textiles -- fading; Raman spectroscopy -- Periodicals; 535.846
• DOI: 10.1002/jrs.4786
• Languages: English
• ISSNs: 0377-0486

Abstract

Abstract : The aim of the present study was to provide experimental procedures for the identification of anthocyanin‐based dyes used in antiquity. In particular, we assessed the possibility to identify anthocyanins, both in plant extracts and in dyed textiles, by means of surface‐enhanced Raman spectroscopy (SERS), a very chemically specific technique that is moreover sensitive to the changes in structures of molecules, phenomena that occur extensively in the chemistry of anthocyanins. The choice of the plant sources (bilberry, elderberry, sumac, purple corn and hollyhock) was based on their attested use in history as dyeing matters. Suitable extraction and pre‐treatment procedures were optimized both for plant sources (berries, cob glumes and flowers) and textiles dyed with such sources in the laboratory, followed by SERS analyses at different pH values. Finally, special attention was paid to the well‐known instability of anthocyanins: dyed wool samples were exposed to artificial aging in order to verify the possibility to identify such molecules also in faded textiles. The achievement of reliable surface‐enhanced Raman spectra from these samples encourages us to suggest the protocol for the analysis of historical objects. Copyright © 2015 John Wiley & Sons, Ltd. Abstract : Surface‐enhanced Raman spectroscopy is exploited to identify anthocyanin‐based dyes used in antiquity both in plant extracts and in dyed textiles. The possibility to identify such molecules, unstable to light, in faded textile samples is also assessed.