Regensburg 2013 – scientific programme
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O: Fachverband Oberflächenphysik
O 88: Molecular Films
O 88.5: Talk
Friday, March 15, 2013, 11:30–11:45, H38
Orientation and ordering in surface-bound DNA hybrids — Caitlin Howell1, Yekkoni Lakshmanan Jeyachandran2, Patrick Koelsch1, and •Michael Zharnikov2 — 1Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany — 2Applied Physical Chemistry, University of Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
Films of surface-bound homo-oligonucleotides on gold were hybridized and characterized using x-ray photoelectron spectroscopy, near-edge x-ray absorption fine structure spectroscopy, and infrared reflection-absorption spectroscopy. First, the effect of rinsing after the hybridization step was studied. Further, the effects of target sequence mismatches and target length mismatches were investigated. The overall orientation of the probe and target strands was found to remaine upright and relatively unchanged despite the presence of up to four sequence mismatches in the target strands, although the total number of hybrids decreased with higher numbers of mismatches. Upright probes were also observed in hybrids formed with targets of shorter length, with a greater number of hybrids present in these films as compared to those formed with longer targets. These results suggest that in DNA films of relatively high densities, such as those tested here, the presence of sequence or length mismatches in target strands does not result in a large disruption of orientation and ordering in surface-bound hybrids. This finding may be useful for nanotechnological applications or utilization of DNA microarrays for biosensing purposes.