title: Quantitative evaluation of blinking in surface enhanced resonance Raman scattering and fluorescence by electromagnetic mechanism.
abstract: We analyze blinking in surface enhanced resonance Raman scattering (SERRS) and surface enhanced fluorescence (SEF) of rhodamine 6G molecules as intensity and spectral instability by electromagnetic (EM) mechanism. We find that irradiation of intense NIR laser pulses induces blinking in SERRS and SEF. Thanks to the finding, we systematically analyze SERRS and SEF from stable to unstable using single Ag nanoparticle (NP) dimers. The analysis reveals two physical insights into blinking as follows. (1) The intensity instability is inversely proportional to the enhancement factors of decay rate of molecules. The estimation using the proportionality suggests that separation of the molecules from Ag NP surfaces is several angstroms. (2) The spectral instability is induced by blueshifts in EM enhancement factors, which have spectral shapes similar to the plasmon resonance. This analysis provides us with a quantitative picture for intensity and spectral instability in SERRS and SEF within the framework of EM mechanism.
authors.affiliation: Nano-bioanalysis Research Group, Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu, Kagawa 761-0395, Japan. tamitake-itou@aist.go.jp
authors.forename: Tamitake
authors.initials: T
authors.lastname: Itoh
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Iga
authors.forename: Hiroharu
authors.initials: H
authors.lastname: Tamaru
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Yoshida
authors.forename: Vasudevanpillai
authors.initials: V
authors.lastname: Biju
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Ishikawa
mesh_terms: D004574:Electromagnetic Fields; D005453:Fluorescence; D012235:Rhodamines / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D013499:Surface Properties
chemical_list: D012235:Rhodamines; C026188:rhodamine 6G