Probing the heterogeneous fluorescence-lifetime behavior of single rhodamine-6G molecules on fused silica

摘要

Heterogeneity in the environments of molecules affects their photophysical parameters. Changes in the local environments or changes within the molecules themselves produces fluctuations in the photophysical parameters. We have explored the fluorescence lifetime and intensity fluctuations of Rhodamine 6G on silica using time correlated single photon counting combined with near-field and far- field scanning optical microscopies, and fluorescence photon-pair correlation measurements in far-field microscopy. In the most recent work, we find complex behavior in the fluorescence lifetime and emission intensity in the millisecond to minute time range that must be associated with changes in both the non-radiative and the radiative decay rates.