Investigation of the blinking phenomenon in SERS

Noble metal thin films have been used for surface enhanced Raman scattering (SERS) nearly since its inception, but only recently has single molecule detection (indicated by blinking of the Raman signal) been demonstrated on these types of films. It has been widely accepted that thin metal films provide an average enhancement of the Raman signal of only 10(6). However, with the combination of the use of high magnification objectives and sensitive detection a new view of thin metal films as a SERS substrate is emerging. Bolstered by these results, our lab has endeavored to further study the optical properties of vapor deposited Ag films. A Stokes-shifted blinking optical response has been observed in our lab in the absence of any specific adsorbate on a silver thin metal film surface. The origin of blinking behavior on Ag this films in the presence and absence of adsorbate was investigated under various environmental conditions. It is anticipated that this system will help elucidate the mechanistic relationship between blinking and in SERS.