Room-temperature 1/3 suppression of diffusive shot noise

Abstract: Diffusive conductors share a universal shot noise reduction of 1/3. This result can be obtained from quantum scattering, Boltzmann-Langevin kinetics, or by symmetric simple exclusion process, but experiments have been limited to cryogenic conditions and the understanding of this universality remains incomplete. Here we show that ferrocene redox cycling in a microfluidic gap is room temperature realization of this universality. An analytical model of the current and its noise is derived and confirmed experimentally. The universal 1/3 shot noise suppression is recovered in the diffusion-limited regime, providing a bridge between mesoscopic physics and electrochemistry, opening a new route for probing molecular dynamics through room-temperature noise measurements.