Fluorescence resonance energy transfer between a quantum dot donor and a dye acceptor attached to DNA

We show that direct coupling of a dye-labelled DNA ( acceptor) to a quantum dot (QD) donor significantly reduces the donor acceptor distance and improves the FRET efficiency: a highly efficient FRET (similar to 88%) at a low acceptor-to-donor ratio of 2 has been achieved at the single-molecule level.