Gold nanoparticles quench fluorescence by phase induced radiative rate suppression.
The fluorescence quantum yield of Cy5 molecules attached to gold nanoparticles via ssDNA spacers is measured for Cy5-nanoparticle distances between 2 and 16 nm. Different numbers of ssDNA per nanoparticle allow to fine-tune the distance. The change of the radiative and nonradiative molecular decay rates with distance is determined using time-resolved photoluminescence spectroscopy. Remarkably, the distance dependent quantum efficiency is almost exclusively governed by the radiative rate.
Dulkeith
E
E
Photonics and Optoelectronics Group, Physics Department and CeNS, Ludwig-Maximilians-Universität München, Germany.
Ringler
M
M
Klar
T A
TA
Feldmann
J
J
Muñoz Javier
A
A
Parak
W J
WJ
D002232:Carbocyanines / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*
D002232:Carbocyanines; D004277:DNA, Single-Stranded; D005456:Fluorescent Dyes; C085321:cyanine dye 5; D006046:Gold