Switchable DNA layers as novel scheme in silicon nanowire based bio-sensing
Final Report Abstract
Within the project, important fundamental knowledge could be gained about certain organophosphonate monolayer systems on aluminum oxide and silicon oxide surfaces. These monolayers are versatile interface systems to be further bio-functionalized for sensing applications. Alkyl mono- and bisphosphonates (monoPAs and bisPAs, respectively) of different carbon chain length were deposited on aluminum oxide surfaces and their film properties were determined using ellipsometry, AFM, contact angle, infrared absorption and xray photoelectron spectroscopy. All monolayers were found to be surface conforming, however, complementary measurements indicated a significant change in conformational order within the bisPA films, in particular for longer chain lengths. As major step for the project target to identify and investigate novel strategies for reduced electrolyte screening in semiconductor field effect sensor devices, the controlled immobilization of a horizontally anchored PNA derivative was studied, using surface analytical tools and impedance spectroscopy measurements. Further investigations will focus on PNA-DNA hybridization detection using this approach, and eventually the transfer of the results to a silicon nanowire platform.
Publications
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Biomolecules in Electric Fields, in “Encyclopedia of Applied Electrochemistry”, Eds.: G. Kreysa, K. Ota, R. F. Savinell, Springer, 2014
M. Tornow
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Disorder-derived, strong tunneling attenuation in bis-phosphonate monolayers, Journal of Physics: Condensed Matter, special issue on “Molecular functionalization of surfaces for device applications”, Journal of Physics: Condensed Matter, Volume 28, Number 9
Anshuma Pathak, Achyut Bora, Kung-Ching Liao, Hannah Schmolke, Antje Jung, Claus-Peter Klages, Jeffrey Schwartz, Marc Tornow
