Unusually Large Exponent for the Inverse Power-Law Blinking of Single Chromophores

In this study of single-particle fluorescence intermittency, we investigate some interesting blinking phenomena of chromophores by Yeow et al. (J. Phys. Chem. A 2006, 110, 1726), showing behavior very different from the usual quantum dots. Using Monte Carlo simulations we demonstrate that the short-time blinking statistics are generally nonexponential but could be characterized by an inverse power law with an effective exponent m far exceeding 2, as observed in some single-chromophores experiments. We show that m for the on-events decreases with the effective diffusion correlation time which increases with light intensity. This work offers an explanation to why m could change from 2.8 to 2.0 in their experiments as the light intensity is quadrupled. 1