Single Molecules Trapped by Dynamic Inhomogeneous Temperature Fields

Synopsis

Single Molecules Trapped by Dynamic Inhomogeneous Temperature Fields
Marco Braun, Andreas P. Bregulla, Katrin Günther, Michael Mertig, and Frank Cichos
Nano Letters 15, 5499-5505 (2015) (Issue of August 12 2015)

We demonstrate a single molecule trapping concept that modulates the actual driving force of Brownian motion—the temperature. By spatially and temporally varying the temperature at a plasmonic nanostructure, thermodiffusive drifts are induced that are used to trap single nano-objects. A feedback controlled switching of local temperature fields allows us to confine the motion of a single DNA molecule for minutes and tailoring complex effective trapping potentials. This new type of thermophoretic microbeaker even provides control over a well-defined number of single molecules and is scalable to large arrays of trapping structures.