title: Self-assembly and hybridization mechanisms of DNA with cationic polythiophene.
abstract: The combination of DNA and π-conjugated polyelectrolytes (CPEs) represents a promising approach to develop DNA hybridization biosensors, with potential applications for instance in the detection of DNA lesions and single-nucleotide polymorphisms. Here we exploit the remarkable optical properties of a cationic poly[3-(6'-(trimethylphosphonium)hexyl)thiophene-2,5-diyl] (CPT) to decipher the self-assembly of DNA and CPT. The ssDNA/CPT complexes have chiroptical signatures in the CPT absorption region that are strongly dependent on the DNA sequence, which we relate to differences in supramolecular interactions between the thiophene monomers and the various nucleobases. By studying DNA-DNA hybridization and melting processes on preformed ssDNA/CPT complexes, we observe sequence-dependent mechanisms that can yield DNA-condensed aggregates. Heating-cooling cycles show that non-equilibrium mixtures can form, noticeably depending on the working sequence of the hybridization experiment. These results are of high importance for the use of π-conjugated polyelectrolytes in DNA hybridization biosensors and in polyplexes.
authors.affiliation: Laboratory for Chemistry of Novel Materials, Center for Innovation in Materials and Polymers, University of Mons - UMONS, 20 Place du Parc, B-7000 Mons, Belgium. mathieu.surin@umons.ac.be.
authors.forename: Jenifer
authors.initials: J
authors.lastname: Rubio-Magnieto
authors.forename: Elias Gebremedhn
authors.initials: EG
authors.lastname: Azene
authors.forename: Jérémie
authors.initials: J
authors.lastname: Knoops
authors.forename: Stefan
authors.initials: S
authors.lastname: Knippenberg
authors.forename: Cécile
authors.initials: C
authors.lastname: Delcourt
authors.forename: Amandine
authors.initials: A
authors.lastname: Thomas
authors.forename: Sébastien
authors.initials: S
authors.lastname: Richeter
authors.forename: Ahmad
authors.initials: A
authors.lastname: Mehdi
authors.forename: Philippe
authors.initials: P
authors.lastname: Dubois
authors.forename: Roberto
authors.initials: R
authors.lastname: Lazzaroni
authors.forename: David
authors.initials: D
authors.lastname: Beljonne
authors.forename: Sébastien
authors.initials: S
authors.lastname: Clément
authors.forename: Mathieu
authors.initials: M
authors.lastname: Surin
mesh_terms: D015374:Biosensing Techniques; D004247:DNA / Q000737:chemistry*; D004573:Electrolytes / Q000737:chemistry; D009691:Nucleic Acid Denaturation; D009943:Organophosphorus Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D013876:Thiophenes / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D004573:Electrolytes; D009943:Organophosphorus Compounds; D011108:Polymers; D013876:Thiophenes; C066730:polythiophene; D004247:DNA