SERS fluctuations of NAD molecules adsorbed on arrays of Au nanocylinders

Abstract

Detection of a single molecule is a highly fluctuating event in surface-enhanced Raman scattering (SERS) measurements. Explaining these dynamic blinking events remains a challenge. To investigate this fluctuating behavior, we manufactured Au nanocylinder arrays. A monolayer of nicotinamide adenine dinucleotide (NAD) on the nanocylinder array exhibited intense and fluctuating Raman lines. Persistent Raman lines were not observed over time. These fluctuations were discussed within the dynamic back-action parametric interaction between the plasmon mode and vibrational modes. The results suggest that the highly efficient SERS structure promotes the formation and destruction of protuberances smaller than 2 nm at random on the nanocylinder surface.