Single-Particle Spectroscopic Study on Fluorescence Enhancement by Plasmon Coupled Gold Nanorod Dimers Assembled on DNA Origami.
Metal-enhanced fluorescence has attracted much attention due to its scientific importance and lots of potential applications. Plasmon coupled metal nanoparticles have been demonstrated to further improve the enhancement effects. Conventional studies of metal-enhanced fluorescence on the bulk systems are complicated by the ensemble average effects over many critical factors with large variations. Here, fluorescence enhancement of ATTO-655 by a plasmon coupled gold nanorod dimer fixed on a DNA origami nanobreadboard was studied on the single-particle level. A series of gold nanorod dimers with linear orientation and different gap distances ranging from 6.1 to 26.0 nm were investigated to explore the plasmon coupling effect on fluorescence enhancement. The results show that the dimer with the smallest gap (6.1 nm) gives the highest enhancement (470-fold), and the enhancement gradually decreases as the gap distance increases and eventually approaches that from a monomer (120-fold). This trend is consistent with the numerical calculation results. This study indicates that plasmon coupling in gold nanorod dimers offers further increased excitation efficiency to achieve large fluorescence enhancement.
‡BioSyM IRG, Singapore-MIT Alliance for Research and Technology, Singapore 138602.
Taishi
T
Zhang
§Department of Chemistry, National University of Singapore, Singapore 117543.
Nengyue
N
Gao
§Department of Chemistry, National University of Singapore, Singapore 117543.
Shuang
S
Li
‡BioSyM IRG, Singapore-MIT Alliance for Research and Technology, Singapore 138602.|⊥Department of Chemical and Biomolecular Engineering and Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37235, United States.
Matthew J
MJ
Lang
‡BioSyM IRG, Singapore-MIT Alliance for Research and Technology, Singapore 138602.|§Department of Chemistry, National University of Singapore, Singapore 117543.
Qing-Hua
QH
Xu
D004247:DNA / Q000737:chemistry*; D005453:Fluorescence; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology; D043942:Nanotubes / Q000737:chemistry*; D013057:Spectrum Analysis; D020349:Surface Plasmon Resonance
D006046:Gold; D004247:DNA
DNA origami; gold nanorod; metal-enhanced fluorescence; plasmon coupling; plasmon resonance; single-molecule spectroscopy