Turning up the noise in nanofluidic channels

We report an experimental technique to increase and control the diffusivity of individual DNA polymers in a nanofluidic environment. We applied white electrical noise with a Gaussian distribution of voltage fluctuations across nanofluidic slits containing fluorescently labeled DNA molecules. The effective diffusivity of the molecules in the direction parallel to the applied fields increased linearly with the noise power, reaching 19 times the thermal diffusivity with an applied noise amplitude of 36 V. This technique, which can subject DNA molecules to noise levels equivalent to 5300 K, enables us to experimentally investigate noise-driven dynamical phenomena in a previously inaccessible regime.