The Silver Colloidal Solutions and Films for Efficient SERS

The silver colloids and silver films are known for their signal enhancing properties in Raman spectroscopy. Surface enhanced raman spectroscopy is a very useful tool to detect molecules at low concentration or even single molecules in examined samples. Here we present a study on the preparation of silver colloidal solution and deposition of silver films on mica. The colloidal solutions were examined by two methods: the UV-VIS spectroscopy to determine their optical properties and atomic force microscopy to determine the size of the particles and structure of the deposited films. The crystal violet (tris(4-(dimethylamino)phenyl)methylium chloride) solution was used as a test sample for evaluation of enhancing properties of silver colloidal solutions and films. These experiments have shown that both colloidal solutions and films, are efficient surface enhanced raman spectroscopy substrates, therefore they can be used in further studies for enhancement of the Raman signal of biopolymers, f.e. poly-saccharides and DNA.