How Graphene Oxide Quenches Fluorescence of Rhodamine 6G

We investigate the fluorescence quenching of Rhodamine 6G (R6G), a well known laser dye with a high fluorescence quantum yield, by as-synthesized graphene oxide (GO) in aqueous solution, which is found to be rather efficient. By means of steady-state and time-resolved fluorescence spectroscopy combined with detailed analysis about the linear absorption variation for this R6G-GO system, the pertinent quenching mechanism has been elucidated to be a combination of dynamic and static quenching. Possible ground-state complexes between R6G and GO during the static quenching have also been suggested. Furthermore, the direction of photoinduced electron transfer between R6G and GO has been discussed.