Dresden 2006 – scientific programme
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AKB: Biologische Physik
AKB 40: Poster Session II
AKB 40.27: Poster
Wednesday, March 29, 2006, 16:30–19:30, P3
Control of Single Nanocrystal Fluorescence Emission in a combined TIRFM/AFM Setup — •Rainer Eckel1, Volker Walhorn1, Christoph Pelargus1, Thomas Nann2, Dario Anselmetti1, and Robert Ros1 — 1Experimental Biophysics and Applied Nanosciences, Faculty of Physics, Bielefeld University, Universitaetsstr. 25, 33615 Bielefeld, Germany — 2Freiburg Materials Research Center (FMF), Stefan-Meier-Str. 21, 79104 Freiburg, Germany
Optomechanical switching and local energy transfer between individual nanoobjects are concepts of growing importance for investigating and manipulating matter at the nanoscale. We report on a new possibility to switch the fluorescence emission of a single semiconductor nanocrystal (quantum dot) by external, optomechanical intervention of an AFM tip. The experimental setup combines atomic force microscopy (AFM) and total internal reflection fluorescence microscopy (TIRFM) in a way that enables laser induced fluorescence imaging of single fluorophores and their simultaneous mechanical addressing with an AFM probe. The fluorescence quenching of an individual semiconductor quantum dot could be controlled mechanically, using an AFM tip functionalized with gold nanoparticles as the quenching agent. It was possible to repeatedly switch the fluorescence emission from the bright (blinking) state to the dark (quenched) state. This opens fascinating possibilities for future simultaneous force spectroscopy and fluorescence resonant energy transfer measurements on single biomolecular complexes.