Dresden 2009 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 9: Nanoparticles II
CPP 9.9: Vortrag
Montag, 23. März 2009, 16:15–16:30, ZEU 114
Spectroscopic study of the complex formation of DNA and a sequence specific minor-groove binding dye: towards molecular metallization — •Markus Schuster1, Glenn Burley2, and Ulrich Rant1 — 1Technische Universität München, Germany — 2University of Leicester, UK
The complex formation of small molecules and DNA represents a promising concept to prepare self-assembled nanostructures. We investigate the interaction of DNA with 3,3*-Diethylthiadicarbocyanine iodide (DiSC2(5)), which has been reported to selectively bind to the minor groove along ATATA sequences. Using extinction and fluorescence spectroscopy, we characterize the binding affinity of DiSC2(5) to different DNA sequences. Binding stoichiometries are determined using the method of continuous variation. The thermodynamic stability of the DNA/ DiSC2(5) complex is investigated and melting temperatures are analyzed. DISC is found to associate with DNA as a dimer with increased, albeit not exclusive, affinity for the ATATA binding cassette.
Aiming to create metal nanoparticles on specific sites along DNA templates, we carried out metallization experiments using DiSC2(5)-dimers as site-selective seeds for metal growth. The development of silver nanoparticles is evidenced by the appearance of plasmon peaks in the absorption spectrum. Dynamic light scattering experiments reveal that the particle diameters range between 10 and 20 nm.