FT‐Raman and NIR‐SERS characterization of the antimalarial drugs chloroquine and mefloquine and their interaction with hematin

Raman and surface‐enhanced Raman scattering (SERS) spectroscopies were employed to probe the interaction of the antimalarial drugs chloroquine (CQ) and mefloquine (MQ) with hematin. NIR‐SERS spectra of both quinoline derivatives were obtained from a colloidal gold surface. Strong chemical interactions of each drug with the Au particles are observed and the similarities of the two NIR‐SERS spectra allowed to predict a similar orientation geometry for both of the drugs on the colloidal surface, namely through the quinoline skeletal part of each molecular structure. Separately, the adsorption behavior of hematin on the Au colloid was studied under nonresonant conditions. In addition, both hematin–antimalarial drug systems (CQ and MQ) were prepared and investigated by NIR‐SERS.