Electrochemical Seeded Growth of Multiple Shapes of Gold Nanostructures and Their Application as SERS Substrates

Surface-enhanced Raman scattering (SERS) is an optical detection method which has the advantages of high specificity and sensitivity. Gold nanostructures are always used to trace detection of chemical molecules because they can produce SERS effect and they are Biocompatible. Our researches used electrochemical and seeded methods to control the growth of nanostructures in two steps. The first step was the nucleation and seed formation of gold on the indium tin oxide (ITO) surface. The second step is the situ growth of gold nanostructures based on seeds. Regulating related parameters of two steps respectively, gold nanostructures with multiple shapes could be synthesized controllably. We used Nile blue A (NBA) as signal molecules to detect the SERS-activity of these gold nanostructures with multiple shapes respectively. The results showed that the gold nanostructures were stable during six months, well reproducible and the SERS-activity of nanostructures depended on the intensity and density of “hot spots”. The gold nanoparticles array containing high intensity and density of hot spots has the strongest SERS-activity. This method is simple, easily controlled, inexpensive, environment friendly and does not need any templates, surfactants or coating agent. It has great potential to be used for large scale synthesis and application of electrochemical and SERS detection in biomedical field.