These transport processes are highly dependent on ordering effects at different scales, 3 whereby the direction and degree of intermolecular organization of π-conjugated assemblies are key factors that determine the efficiency of energy transport. 4– 7 This generally occurs via diffusion of excitons, which are electronically excited states of molecules that are created by light absorption or other electron transfer processes.

1– 3 In both photosynthetic complexes and in most optoelectronic devices, excitation energy transfer process plays a central role. Supramolecular assembly is a recurring theme in nature that plays a significant role in the function of biological assemblies and is a widely used strategy to organize molecular components in organic electronic devices. This unique material design incorporates two different semiconducting units coassembled within peptide nanostructures and offers a new platform for the engineering of energy migration through bioelectronic materials in aqueous environments. The reversibility of nanostructure formation and the associated photophysical responses under different conditions (pH, temperature) were also studied. These spectral changes were observed even at minute amounts of the acceptor (starting at 1 mol%), suggesting that exciton migration is involved in energy transport and supporting a funnel-like energy transduction mechanism. These peptide-based assemblies encourage energy migration along the stacking axis, thus resulting in the quenching of donor emission peaks along with the development of new spectral features reminiscent of acceptor emission. Steady-state and time-resolved photophysical measurements demonstrate energy transfer within π-conjugated peptide nanostructures composed of oligo-( p-phenylenevinylene)-based donor units and quaterthiophene-based acceptor units in completely aqueous environments.

Purebasic 4.41