Trapping nanoscopic objects to observe their dynamic behaviour for extended periods of time is an ongoing quest. Particularly, sub-100nm transparent objects are hard to catch and most techniques rely on immobilisation or transient diffusion through a confocal laser focus. We present an Anti-Brownian ELectrokinetic trap (pioneered by A. E. Cohen and W. E. Moerner) to hold nanoparticles and individual FoF1-ATP synthase proteins in solution. We are interested in the conformational dynamics of this membrane-bound rotary motor protein that we monitor using single-molecule FRET. The ABELtrap is an active feedback system cancelling the nano-object's Brownian motion by applying an electric field. We show how the induced electrokinetic forces confine the motion of nanoparticles and proteoliposomes to the centre of the trap.
@article{arxiv.1701.03422,
title = {Confining Brownian motion of single nanoparticles in an ABELtrap},
author = {Maria Dienerowitz and Thomas Heitkamp and Thomas Gottschall and Jens Limpert and Michael Borsch},
journal= {arXiv preprint arXiv:1701.03422},
year = {2017}
}