SERS of cytosine and its methylated derivatives on metal colloids

SERS spectra of cytosine, 1‐methylcytosine, 5‐methylcytosine and 1,5‐dimethylcytosine on silver and on copper colloids are reported. A study of the influence of pH on the normal Raman spectra of these compounds was made in order to understand better the behaviour of these molecules on metal surfaces. The results obtained indicate remarkable changes in the type of adsorbate—metal interactions depending on the metal used as the SERS support. These interactions are also influenced by the presence of methyl groups in the cytosine molecule.