Dark State-Modulated Fluorescence Correlation Spectroscopy for Quantitative Signal Recovery.

ABSTRACT: Excitation of few-atom Ag cluster fluorescence produces significant steady-state dark state populations that can be dynamically optically depopulated with long wavelength coillumination. Modulating this secondary illumination dynamically repopulates the ground state, thereby directly modulating nanodot fluorescence without modulating background. Both fast and slow modulation enable unmodulated background to be quantitatively removed in fluorescence correlation spectroscopy (FCS) through simple correlation-based averaging. Such modulated dual-laser FCS enables recovery of pure Ag nanodot fluorescence correlations even in the presence of strong, spectrally overlapping background emission. Fluorescence recovery is linear with Fourier amplitude of the modulated fluorescence, providing a comple

SUBMITTER: Hsiang JC 

PROVIDER: S-EPMC5218585 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature