Detection of collapsed and ordered polymer structures by fluorescence resonance energy transfer in stiff homopolymers: bimodality in the reaction efficiency distribution

Abstract

Distribution of fluorescence resonance energy transfer (FRET) efficiency between the two ends of a stiff homopolymer chain is calculated by Brownian dynamics simulations. We show that the various collapsed and/or ordered conformations (spherical, rod, and toroidal) of a stiff polymer chain can be effectively distinguished by using the fluorescence resonance energy transfer technique. In particular, FRET efficiency distribution is unimodal at low chain stiffness (where collapsed structure is disordered) but becomes bimodal with increasing chain stiffness, when ordered structures are formed. We have also presented a simple theoretical analysis for the evaluation of the structural parameters.