DNA-Organized Light-Harvesting Antennae: Energy Transfer in Polyaromatic Stacks Proceeds through Interposed Nucleobase Pairs

Abstract

DNA-based light-harvesting antennae with varying arrangements of light-absorbing phenanthrene donor units and a pyrene acceptor dye were synthesized and tested for their light-harvesting properties. Excitation of phenanthrene is followed by rapid transfer of the excitation energy to the pyrene chromophore. A block of six light-absorbing phenanthrenes was separated from the site of the acceptor in a stepwise manner by an increasing number of intervening AT base pairs. Energy transfer occurs through interposed AT base pairs and is still detected when the phenanthrene antenna is separated by 5 AT base pairs.