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Effects of metallic silver island films on resonance energy transfer between N , N ′‐(dipropyl)‐tetramethyl‐ indocarbocyanine (Cy3)‐ and N , N ′‐(dipropyl)‐tetramethyl‐ indodicarbocyanine (Cy5)‐labeled DNA
Author(s) -
Malicka Joanna,
Gryczynski Ignacy,
Kusba Jozef,
Lakowicz Joseph R.
Publication year - 2003
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.10507
Subject(s) - acceptor , förster resonance energy transfer , metal , chemistry , covalent bond , energy transfer , resonance (particle physics) , crystallography , analytical chemistry (journal) , chemical physics , atomic physics , chromatography , physics , optics , condensed matter physics , organic chemistry , fluorescence
Resonance energy transfer (RET) is typically limited to distances below 60 Å, which can be too short for some biomedical assays. We examined a new method for increasing the RET distances by placing donor‐ and acceptor‐labeled DNA oligomers between two slides coated with metallic silver particles. A N , N ′‐(dipropyl)‐tetramethylindocarbocyanine donor and a N , N ′‐(dipropyl)‐tetramethylindodicarbocyanine acceptor were covalently bound to opposite 5′ ends of complementary 23 base pair DNA oligomers. The transfer efficiency was 25% in the absence of silver particles or if only one slide was silvered, and it increased to an average value near 64% between two silvered slides. The average value of the Forster distance increased from 58 to 77 Å. The energy transfer data were analyzed with a model assuming two populations of donor–acceptor pairs: unaffected and affected by silver island films. In an affected fraction of about 28%, the apparent energy transfer efficiency is near 87% and the Forster distance increases to 119 Å. These results suggest the use of metallic silver particles to increase the distances over which RET occurs in biomedical and biotechnology assays. © 2003 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 70: 595–603, 2003