Design Strategies and Sensing Protocols Based on Luminescent Ensembles of Conjugated Polyelectrolytes and Square-Planar Metal Complexes Via Electrostatic Assembly and Non-Covalent Interactions

Abstract

Recent work by our group has demonstrated the self-assembly of cationic alkynylplatinum(II) terpyridine complexes onto anionic polyelectrolytes through electrostatic interactions, resulting in remarkable UV-vis absorption and emission spectral changes. Inspired by the rich chromophoric and luminescence properties of conjugated polyelectrolytes, our group has explored the study of the interactions between cationic square-planar metal complexes and anionic conjugated polyelectolytes. Förster resonance energy transfer (FRET) from the conjugated polyelectolytes to the metal complexes has been revealed from steady-state and time-resolved emission studies, and the FRET efficiency has been found to depend on the extent of aggregation of the metal complexes. Through modulation of the aggregation processes via specific interactions with various biomolecules, changes in the FRET efficiency have been found to result in emission spectral changes in the visible to near-infrared region, allowing the exploitation of “proof-of-principle” concepts for the development of sensing protocols for label-free detection of biomolecules.