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Title: Multiplexed measurements by time resolved spectroscopy using colloidal CdSe/ZnS quantum dots

Multiplexed measurements of analytes in parallel is a topical demand in bioanalysis and bioimaging. An interesting alternative to commonly performed spectral multiplexing is lifetime multiplexing. In this Letter, we present a proof of principle of single-color lifetime multiplexing by coupling the same fluorophore to different nanoparticles. The effective lifetime of the fluorophores can be tuned by more than one order of magnitude due to resonance energy transfer from donor states. Measurements have been done on a model systems consisting of ATTO-590 dye molecules linked to either gold particles or to CdSe/ZnS core shell quantum dots. Both systems show the same luminescence spectrum of ATTO-590 dye emission in continuous wave excitation, but can be distinguished by means of time resolved measurements. The dye molecules bound to gold particles exhibit a mono-exponential decay with a lifetime of 4.5 ns, whereas the dye molecules bound to CdSe/ZnS dots show a nonexponential decay with a slow component of about 135 ns due to the energy transfer from the quantum dots. We demonstrate the fundamental possibility to determine the mixing ratio for dyes with equal luminescence spectra but very different transients. This opens up a pathway independent of the standard optical multiplexing with many differentmore » fluorophores emitting from the near ultraviolet to the near infrared spectral region.« less
Authors:
; ; ; ; ;  [1]
  1. Department of Physics and Materials Sciences Center, Philipps-University of Marburg, Renthof 5, D-35032 Marburg (Germany)
Publication Date:
OSTI Identifier:
22280571
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CADMIUM SELENIDES; COUPLING; EMISSION SPECTRA; EMISSION SPECTROSCOPY; ENERGY TRANSFER; EXCITATION; GOLD; HETEROJUNCTIONS; LIFETIME; LUMINESCENCE; QUANTUM DOTS; TIME RESOLUTION; ULTRAVIOLET RADIATION; ZINC SULFIDES