The syntheses of a number of azo and azine dyes with various surface attachment groups is described. The dyes use different methods of achieving surface complexing and are evaluated for their suitability as multiple labels for SERRS. The surface complexing agents, 8-hydroxyquinoline, benzotriazole, and pyridine are both shown to form robust layers on the silver surface. The relative intensities of the SERRS signals from each dye were shown to be predictive by considering the molar absorption coefficient at the laser excitation frequency.
McHugh, C. J., Docherty, F. T., Graham, D., & Smith, W. E. (2004). SERRS Dyes: part 2. synthesis and evaluation of dyes for multiple labelling for SERRS. Analyst, 129(1), 69-72. https://doi.org/10.1039/B311321C