• Home
  • Search Results
  • Plasmonic molecular nanohybrids-spectral dependence of fluorescence quenching.

Plasmonic molecular nanohybrids-spectral dependence of fluorescence quenching.

International journal of molecular sciences (2012-02-09)
Maria Olejnik, Lukasz Bujak, Sebastian Mackowski
ABSTRACT

We demonstrate strong spectral dependence of the efficiency of fluorescence quenching in molecular systems composed of organic dyes and gold nanoparticles. In order to probe the coupling with metallic nanoparticles we use dyes with varied spectral overlap between the plasmon resonance and their absorption. Hybrid molecular structures were obtained via conjugation of metallic nanoparticles with the dyes using biotin-streptavidin linkage. For dyes featuring absorption above the plasmon excitation in gold nanoparticles, laser excitation induces minute changes in the fluorescence intensity and its lifetime for both conjugated and non-conjugated mixtures, which are the reference. In contrast, when the absorption of the dye overlaps with the plasmon resonance, the effect is quite dramatic, reaching 85% and 95% fluorescence quenching for non-conjugated and conjugated mixtures, respectively. The degree of fluorescence quenching strongly depends upon the concentration of metallic nanoparticles. Importantly, the origin of the fluorescence quenching is different in the case of the conjugated mixture, as evidenced by time-resolved fluorescence. For conjugated mixtures of dyes resonant with plasmon, excitation features two-exponential decay. This is in contrast to the single exponential decay measured for the off-resonant configuration. The results provide valuable insight into spectral dependence of the fluorescence quenching in molecular assemblies involving organic dyes and metallic nanoparticles.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Atto 488 NHS ester, BioReagent, suitable for fluorescence, ≥80% (coupling to amines)
Sigma-Aldrich
Atto 488, suitable for fluorescence, ≥90% (HPCE)
Sigma-Aldrich
Atto 488-Biotin, BioReagent, suitable for fluorescence, ~75% (HPCE)
Sigma-Aldrich
Atto 488 maleimide, BioReagent, suitable for fluorescence, ≥90% (coupling to thiols)
Sigma-Aldrich
Atto 488 amine
Sigma-Aldrich
Atto 488 azide
Sigma-Aldrich
Atto 488 iodoacetamide

Social Media

LinkedIn icon
Twitter icon
Facebook Icon
Instagram Icon

MilliporeSigma

Research. Development. Production.

We are a leading supplier to the global Life Science industry with solutions and services for research, biotechnology development and production, and pharmaceutical drug therapy development and production.

© 2021 Merck KGaA, Darmstadt, Germany and/or its affiliates. All Rights Reserved.

Reproduction of any materials from the site is strictly forbidden without permission.