Single molecule spectral dynamics at room temperature

Abstract

Sequences of single-molecule fluorescence spectra are presented with integration times per spectrum as short as 25 ms. By reducing averaging effects in the time domain, the vibronic bands appear better resolved, often they show distinct bands instead of a shoulder in time-averaged spectra. Furthermore, we note that the fluctuation of the intensity ratio of the vibronic bands can considerably contribute to room-temperature spectral diffusion. This is in contrast to spectral diffusion of narrow homogenous Lorentzian absorption line profiles at cryogenic temperatures.