title: Re-examining the origins of spectral blinking in single-molecule and single-nanoparticle SERS.
abstract: Single metal nanoparticles and nanoaggregates are known to emit intense bursts of surface-enhanced Raman scattering (SERS) in an intermittent on and off fashion. The characteristic "blinking" timescales range from milliseconds to seconds. Here we report detailed temperature dependence (both heating and cooling) and light-intensity studies to further examine the origins of this intriguing phenomenon. The results indicate that blinking SERS contains both a thermo-activated component and a light-induced component. Several lines of evidence suggest that the observed fluctuations are caused by thermally activated diffusion of individual molecules on the particle surface, coupled with photo-induced electron transfer and structural relaxation of surface active sites or atomic-scale roughness features.
authors.affiliation: Department of Chemistry, Western Washington University, Bellingham WA 98225, USA. semory@chem.wwu.edu
authors.forename: Steven R
authors.initials: SR
authors.lastname: Emory
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Jensen
authors.forename: Teresa
authors.initials: T
authors.lastname: Wenda
authors.forename: Mingyong
authors.initials: M
authors.lastname: Han
authors.forename: Shuming
authors.initials: S
authors.lastname: Nie
mesh_terms: D053758:Nanoparticles; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties; D013696:Temperature