Pharmaceutical applications of a nanospectroscopic technique: Surface-enhanced Raman spectroscopy

•Surface-enhanced Raman spectroscopy (SERS) is a widely applicable mode of Raman Spectroscopic technique in the pharmaceutical field.•SERS is a vibrational nanospectroscopic technique to determine the even smallest amount of the drug and their metabolites in the complex biological matrix using metal nanoparticles as SERS substrate.•The technique is used for not only determination of drug and its metabolites but also the whole drug applications from drug discovery to in vitro and in vivo imaging.•The technique with high sensitivity can be couple with separation technique such as microfluidics, LC, and CE using either a nanostructured surface or colloidal nanoparticles to detect molecular structures down to single molecule from complex mixtures.