Laboratoire d’Electronique Moléculaire, DRECAM/SPEC
Dielectrophoresis (DEP) of different length DNA fragments (27 bp – 8 kbp) was studied using in situ confocal microscopy. The experimental results combined with the FEM-simulation reveal information about the polarizability of DNA . Confocal microscopy was also applied to study the thiol-based DNA immobilization to gold electrodes  and use of carbon nanotube (CNT) for more efficient dielectrophoretic trapping  of DNA.
Utilizing the previously developed trapping and immobilization technique, the electrical conductivity of 414 bp long double-stranded DNA was studied on the single molecule level. Increase of the ambient humidity accomplished a remarkable increase in the electrical (DC) conductivity, which was explained by the conformational recovery of the double-helix .
 S. Tuukkanen, A. Kuzyk, J.J. Toppari, H. Häkkinen, V.P. Hytönen, E. Niskanen, M. Rinkiö, and P. Törmä, Nanotechnology 18, 295204 (2007).
 S. Tuukkanen, J.J. Toppari, A. Kuzyk, L. Hirviniemi, V.P. Hytönen, T. Ihalainen, and P. Törmä, Nano Lett. 6, 1339 (2006).
 S. Tuukkanen, A. Kuzyk, J.J. Toppari, V.P. Hytönen, T. Ihalainen, and P. Törmä, Appl. Phys. Lett. 87, 183102 (2005).