Individual molecules of dye-labeled DNA act as a reversible two-color switch upon application of an electric field

Abstract

Reversible switching of the fluorescence of an individual dye-labeled DNA molecule is possible by utilizing an electric field applied in the tip of a nanopipette (see picture; FRET = fluorescence resonance energy transfer). The electric field appears to alter the conformation of the acceptor dye only, resulting in a significant change in its quantum yield.