Regensburg 2007 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
DS: Fachverband Dünne Schichten
DS 4: Nanoengineered Thin Films
DS 4.5: Talk
Monday, March 26, 2007, 12:15–12:30, H34
Organophosphonate Functionalized Silicon Nanowires for DNA Hybridization Studies — •Daniel Pedone1, Anna Cattani Scholz1, Stefan Birner1, Manish Dubey2, Jeffrey Schwartz2, Marc Tornow3, and Gerhard Abstreiter1 — 1WSI, TU München — 2Princeton University, USA — 3IHT, TU Braunschweig
Semiconductor nanowire field effect devices have great appeal for label-free sensing applications due to their sensitivity to surface potential changes that may originate from charged adsorbates. In addition to requiring high sensitivity, suitable passivation and functionalization of the semiconductor surface is obligatory. We have fabricated both freely suspended and oxide-supported silicon nanowires from Silicon-on-Insulator substrates using standard nanopatterning methods (EBL, RIE) and sacrificial oxide layer etching. Subsequent to nanofabrication, the devices were first coated with an hydroxyalkylphosphonate monolayer and then bound via bifunctional linker groups to single stranded DNA or PNA oligonucleotides, respectively. We investigated DNA hybridization on such functionalized nanowires using a difference resistance setup, where subtracting the reference signal from a second wire could be used to exclude most non-specific effects. A net change in surface potential on the order of a few mV could be detected upon addition of the complementary DNA strand. This surface potential change corresponds to the hybridization of about 1010cm−2 probe strands according to our model calculations that takes into account the entire hybrid system in electrolyte solution.