Electromechanical switching of DNA
We manipulate monolayers of short DNA oligonucleotides that are tethered to gold surfaces in aqueous electrolyte solutions by the electrical potential at the electrode. The electrostatic interaction between the charged metal substrate and the negatively charged DNA allows the controlled dynamic orientation change of the molecular film, reversibly switching between a "lying" and a "standing" state. This electromechanical switching is monitored directly by using a contactless - mode fluorescence measurement technique. The electromodulation of biomolecule layers allows fundamental investigations of the molecular dynamics of polyelectrolytes at solid/liquid interfaces. Moreover, this technique which has been developed in collaboration with the Fujitsu Laboratories opens novel prospects for applications in the field of biosensing (DNA arrays). The work is financed by the Fujitsu Laboratories of Europe.
