SERS substrates based on silver nanoparticles and graphene oxide

Abstract

Simple work methods for preparing active coatings for surface-enhanced Raman scattering (SERS) are demonstrated in the article. SERS active films of colloidal silver nanoparticles and composites based on graphene oxide and silver nanoparticles were obtained. The prepared disperse solutions of silver nanoparticles and graphene oxide/Ag nanoparticles composites have different stability. Using a scanning electron microscope, the structure of the prepared films was studied. A comparative characteristic of the obtained SERS active substrates is given. The dye Rhodamine 6G was used as the test substance. It was shown that the smallest enhancement of the Raman signal is produced by a coating of colloidal silver nanoparticles, while the graphene oxide/Ag nanoparticles composite obtained by the 2-stage method provides the greatest gain. The different ability to amplify the Raman signal is explained by the difference in the structure and composition of the obtained SERS active films. All prepared coatings make it easy to detect low dye concentrations (from a 10–6 M solution) both with resonance (532 nm) and nonresonance (632.8 nm) excitation.