A Single Molecule View of Conformational Switching of DNA Tethered to a Gold Electrode

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Eric Josephs, Assistant Professor (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/

Abstract: Surfaces that can actively regulate binding affinities or catalytic properties in response to external stimuli are a powerful means to probe and control the dynamic interactions between the cell and its microenvironment. Active surfaces also enable novel functionalities in biosensors and biomolecular separation technologies. Although electrical stimuli are often appealing due to their speed and localization, the operation of these electrically activated surfaces has mostly been characterized with techniques averaging over many molecules. Without a molecular-scale understanding of how biomolecules respond to electric fields, achieving the ultimate detection sensitivity or localized biological perturbation with the ultimate resolution would be difficult. Using electrochemical atomic force microscopy, we are able to follow the conformational changes of individual, short DNA molecules tethered to a gold electrode in response to an applied potential. Our study reveals conformations and dynamics that are difficult to infer from ensemble measurements: defects in the self-assembled monolayer (SAM) significantly perturb conformations and adsorption/desorption kinetics of surface-tethered DNA; on the other hand, the SAM may be actively molded by the DNA at different potentials. These results underscore the importance of characterizing the systems at the relevant length scale in the development of electrically switchable biofunctional surfaces. [The original abstract for this article contains (characters/images) that cannot be displayed here. Please click on the link below to read the full abstract and article.]

Additional Information

Journal of the American Chemical Society, 2012, 134 (24), 10021– 10030
Language: English
Date: 2012
DNA, self-assembled monolayer, atomic force microscopy, particle-counting voltammogram, biofunctional surfaces

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