Berlin 2005 – wissenschaftliches Programm
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AKB: Biologische Physik
AKB 200: Poster Session II
AKB 200.9: Poster
Dienstag, 8. März 2005, 17:00–19:00, Poster TU C
Force Spectroscopy with a Novel Small Focus AFM — •Volker Walhorn1, Joerg Martini1, Rainer Eckel1, Jeroen Steen2, Tobias Kramer2, Bjoern Decker3, Robert Ros1, Dario Anselmetti1, Juergen Brugger2, and Juergen Mattay3 — 1Department of Biophysics and Applied Nanosciences, University of Bielefeld, Germany — 2Inst. de Microsystèmes, EPFL, Lausanne, Switzerland — 3Department of Organic Chemistry, University of Bielefeld, Germany
Atomic force microscopy has become potent tool for investigating inter- and intramolecular interactions. Single molecule force spectroscopy on supramolecular guest-host-complexes reveal information about the depth of the binding pocket and thermal off-rates.
Sensitivity and resolution are immanently conntected to the cantilever’s mechanical properties. The cantilever’s thermal noise induced by Brownian Motion of the surrounding medium is a fundamental limit of resolution. As the Nyquist Theorem is valid for the thermal white noise of a cantilever, reduction of the viscous damping by downsizing the cantilever’s dimensions is compulsory. Furthermore, the resonant frequency is increased which extends experimental bandwidth and thus enables high speed measurements. Unfortunately small cantilevers cannot be used with commercially available AFM, since the laserfocus is too large.
We present results of single molecule force spectroscopy measurements on Calixarene-Ammonium-Complexes acquired with our home-built small focus AFM. As predicted, small cantilevers show favourable properties as increased resonant frequency and lower viscous damping.