Quantum Dots (QD-Dye Conjugate) are Ideal Candidates for FRET Investigations Using TIRMicroscopy

Abstract

Total Internal Reflection Microscopy has been employed to investigate Förster resonance energy transfer FRET for QD-dye conjugate system. QDs based donor systems are ideal for FRET for many reasons, one of them is that their broad excitation cross section which means that the direct excitation of the acceptor can be minimised via QD excitation at much shorter wavelengths, where little absorbance occurs in the acceptor. Förster resonance energy transfer (FRET) is a mechanism at which energy transfer between two fluorophores that occurs over a much shorter distance. A donor fluorophore in its excited state can transfer energy by a non- radiative, a long range dipole-dipole coupling mechanism to an acceptor fluorophore in close proximity (typically <10 nm). This is exactly the regime relevant to many biochemical processes and so significant effort has gone into developing FRET in recent years as a new tool for probing dynamics in condensed phase systems.