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Proceedings Paper

Modulation of quantum dot photoemission based on fluorescence resonance energy transfer to a photochromic dye acceptor
Author(s): Igor L. Medintz; Aaron R. Clapp; Scott A. Trammel; Hedi M. Mattoussi
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Paper Abstract

We demonstrate the use of a photochromic dye to achieve fluorescence resonance energy transfer (FRET) modulation between a QD donor and the dye acceptor brought in close proximity in a selfassembled QD-protein-dye conjugate. The E. coli maltose binding protein (MBP) appended on its C-terminal with an oligohistidine attachment domain, immobilized onto CdSe-ZnS core-shell QDs was labeled with a sulfo-N-hydroxysuccinimide activated photochromic BIPS molecule (1',3-dihydro-1'-(2-carboxyethyl)-3,3-dimethyl-6-nitrospiro[2H-1-benzopyran-2,2'-(2H)-indoline]). Two different dye-to-MBP-protein ratios of 1:1 and 5:1 were used. The ability of MBP-BIPS to modulate QD photoluminescence was tested by switching BIPS from the colorless spiropyran (SP) to the colored merocyanine (MC) using irradiation with white light (>500 nm) or with UV light (~365 nm), respectively. QDs surrounded by ~20 MBP-BIPS with a dye to protein ratio of 1 showed ~25% loss in their photoemission with consecutive repeated switches, while QDs surrounded by ~20 MBP-BIPS with BIPS to MBP ratio of 5 produced a substantially more pronounced rate of FRET where the QD emission was quenched by ~60%. This result suggests the possibility of using QD-protein conjugates to assemble reversible FRET nanoassemblies where the QD emission can be controlled by changing the properties of the acceptors dyes bound to the protein.

Paper Details

Date Published: 29 December 2004
PDF: 8 pages
Proc. SPIE 5593, Nanosensing: Materials and Devices, (29 December 2004); doi: 10.1117/12.570681
Show Author Affiliations
Igor L. Medintz, Naval Research Lab. (United States)
Aaron R. Clapp, Naval Research Lab. (United States)
Scott A. Trammel, Naval Research Lab. (United States)
Hedi M. Mattoussi, Naval Research Lab. (United States)


Published in SPIE Proceedings Vol. 5593:
Nanosensing: Materials and Devices
M. Saif Islam; Achyut K. Dutta, Editor(s)

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