Self-assembly of π-conjugated structures - DNA: A supramolecular engineering approach

Hybrid self-assembled structures combining biomolecules with synthetic (macro)molecules constitute an emerging class of materials, with applications in biosensors and drug delivery systems for instance. Recently, studies have been carried out on -conjugated polyelectrolytes binding to DNA, and fluorescence properties of the complexes have been exploited to detect complementary single-stranded DNA sequences.1 This concept has also been remarkably used to accurately determine DNA concentration down to nanomolar range, and to probe conformational changes of aptamer upon binding to human -thrombin.2

In this frame, we study the self-assembly of -conjugated oligomers or polymers with specific DNA structures (oligonucleotides), in order to elaborate novel hybrid materials possessing specific optical and (bio)recognition properties. With this aim, we develop a supramolecular engineering approach, which combine theoretical molecular modelling, (chir)optical spectroscopy, and scanning probe microscopy. This allows us to develop models of self-assembly and to establish a deep understanding of the structure-properties relationships in these supramolecular objects. In this talk, we will particularly highlight two approaches: i) the DNA base template approach, which deals with the base recognition properties to scaffold assemblies of -conjugated oligomers with specific 2D or 3D supramolecular organization, which is exploited to develop supramolecular wires on surfaces for organic electronics or to direct energy-transfer processes along DNA templates;3 ii) the polymer-DNA approach, which deals with the self-assembly of cationic polymers and functional nucleic acids, with the intention to construct highly selective chemo- and bio-sensors. For both approaches, we particularly highlight the role guanine scaffolds and G-quadruplexes structures in the self-assembly processes.