Surface enhanced Raman scattering studies of 1,4-diaminoanthraquinone dye in Ag colloid

Surface enhanced Raman scattering studies are carried out for 1,4-diaminoan thraquinone dye [1,4-DAAQ] in Ag colloid in order to understand the enhance ment effect and the nature of interaction between the dye molecule and Ag s urface. Detailed analysis of the enhanced vibrational bands in the SERS spe ctrum shows that the 1,4-DAAQ molecule is not adsorbed through its coordina ting sites, because of intramolecular hydrogen bond formation. The 1,4-DAAQ molecule is seen having 'flat on' orientation. Laser induced fluorescence measurements in different solvents and in different pH confirm the intramol ecular hydrogen bond formation.