In situ detection of flavonoids in weld-dyed wool and silk textiles by surface-enhanced Raman scattering

Abstract

Luteolin and apigenin flavonoid have been detected in silk and wool fibres dyed with weld (Reseda luteola L.) through surface-enhanced Raman scattering (SERS) measurements carried out on the fibre. For such purpose, Ag nanoparticles were produced and immobilised in situ via the laser photoreduction of a silver nitrate water solution in contact with the fibre. Control SERS spectra of pure luteolin and apigenin, as well as of mixtures of them, on analogous Ag nanoparticles were also obtained. In this work flavonoids with a similar molecular structure were identified on dyed fibres for the first time without previously hydrolysing the mordant-dye complex.