Controlled Amplification of DNA Brownian Motion Using Electrokinetic Noise

The application of voltage noise with the same statistical properties as fundamental thermal noise controllably amplified the Brownian motion of λ DNA molecules suspended in solution inside a nanoslit. We analyze the trajectories of single molecules and find that their self-diffusivity in the direction of the applied electric field increases in proportion with the variance of the voltage noise. The highest effective diffusivity achieved corresponds to an effective temperature of 5300 K. However, unlike thermal noise, the voltage noise causes correlated fluctuations of different molecules and their segments. This technique unlocks a previously inaccessible effective temperature regime for studies and applications of noise-dependent phenomena.