Controlled aggregation of DNA functionalized poly(phenylene-vinylene)

Abstract

The morphology of conjugated polymers strongly influences their optical and electronic properties and affects their performance in polymer devices. Using optical spectroscopy and atomic force microscopy, we investigate the fluorescence properties and the aggregation state of DNA-functionalized poly(phenylene-vinylene). We show that polymer aggregation can be controlled in solution through ion and DNA interactions; aggregation is induced in the presence of divalent cations and can be reversed by adding sequence specific DNA. These interactions provide ways to tune polymer aggregation on the timescale of minutes and allows tuning of the polymer's optical properties.

A Single Molecule Polyphenylene-Vinylene Photonic Wire

“…These effects were later ascribed to polymer aggregation due to the presence of even minute amounts of Mg 2+ ions in solution, whereas high concentrations of Na + ions caused minimal aggregation. 37 It was therefore crucial for us to develop a protocol that allowed efficient immobilization of poly(APPV-DNA) on DNA origami in the absence of Mg 2+ . The DNA nanostructures were therefore assembled in 1 M NaCl with 1xTAE, and the polymer immobilization was performed at a NaCl concentration of 100 mM.…”

“…Initial studies with poly­(APPV-DNA) as a photonic wire were hampered by dramatic changes in fluorescence quantum yield combined with a bathochromic shift observed for the polymer over time. These effects were later ascribed to polymer aggregation due to the presence of even minute amounts of Mg 2+ ions in solution, whereas high concentrations of Na + ions caused minimal aggregation . It was therefore crucial for us to develop a protocol that allowed efficient immobilization of poly­(APPV-DNA) on DNA origami in the absence of Mg 2+ .…”

“…We previously reported on the synthesis of phenylene-vinylene and fluorene-based brush polymers containing DNA strands extending from the repeat units. , The phenylene-vinylene-based polymer DNA conjugate, poly­(APPV-DNA), was routed on DNA origami by hybridization of the DNA on the polymer to tracks of extended staple strands on the surface of the origami structure. It was also shown that excitation energy could be transferred between small molecule dyes and poly­(APPV-DNA). − We and others have further shown that the fluorescence properties of conjugated polymers and oligomers in DNA nanostructures can be tuned through interaction with salts, detergents, or other reagents. − With the ability to immobilize conjugated polymers on DNA origami, we here move on to study the capability of poly­(APPV-DNA) as a polymer photonic wire.…”

DNA-Programmed Chemical Synthesis of Polymers and Inorganic Nanomaterials

“…7b) [60]. The controlled aggregation of poly(APPV-DNA) polymers in solution through varying the ionic environment and sequence-specific DNA interactions was demonstrated in their recent work [61].…”

Single molecule fluorescence investigations of DNA-based self-assembledstructures

“…The method allows resolving the different conformations of these structurally heterogeneous systems and studying the properties of fluorescent molecules arranged onto DNA templates. I will present our single molecule fluorescence data analysis platform [3] and investigations of the structural heterogeneity and dynamics of different DNA structures [4,5] and of fluorescent DNA modified conjugated polymers [6,7]. Our results give insights into DNA folding and local structure as well as guidelines to achieve nanoscale spatial control of fluorescent molecules.…”