title: Experimental evidence of plasmophores: plasmon-directed polarized emission from gold nanorod-fluorophore hybrid nanostructures.
abstract: We show that the fluorescence emission from individual hybrid nanostructures composed of Au nanorod cores and oxazine 725-embedded mesostructured silica shells is strongly polarized, with the degree of polarization being equal to that of the light scattered by the nanorod and varying from 0 to 1 as the longitudinal plasmon resonance wavelength is increased. Our analyses indicate that the interactions of the plasmon resonance of the nanorod with the excitation and emission processes of the fluorophores are temporally separated under unsaturated excitation conditions. The emission polarization is found through electrodynamic calculations to arise from the plasmon-coupled emission instead of the plasmon-enhanced excitation polarization. The emission carries the direction and polarization properties that are essentially determined by the dipolar plasmon of the nanorod antenna. Our results therefore provide direct and concrete evidence for the plasmophore that has been proposed recently for plasmon-enhanced fluorescence.
authors.affiliation: Department of Physics, The Chinese University of Hong Kong , Shatin, Hong Kong SAR.
authors.forename: Tian
authors.initials: T
authors.lastname: Ming
authors.forename: Lei
authors.initials: L
authors.lastname: Zhao
authors.forename: Huanjun
authors.initials: H
authors.lastname: Chen
authors.forename: Kat Choi
authors.initials: KC
authors.lastname: Woo
authors.forename: Jianfang
authors.initials: J
authors.lastname: Wang
authors.forename: Hai-Qing
authors.initials: HQ
authors.lastname: Lin
mesh_terms: D005453:Fluorescence; D006046:Gold / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D011789:Quantum Theory; D012822:Silicon Dioxide / Q000737:chemistry; D020349:Surface Plasmon Resonance; D013499:Surface Properties
chemical_list: D006046:Gold; D012822:Silicon Dioxide