Study of energy transfer mechanism from CdS quantum dots to Rhodamine 101 in reverse micelle medium

In this study, fluorescence resonance energy transfer (FRET) between CdS quantum dots (QDs) and Rhodamine 101 was investigated in reverse micelles. CdS QDs as donor were synthesized by using reverse micelle method. The particle sizes of CdS QDs were found as 1.18 +/- 0.05 for QD1 and 2.11 +/- 0.25 nm for QD2 with TEM measurements. It was determined that the fluorescence intensity of the QDs quenched as the concentration of Fth101 increased. The effect of the concentration of dye on the quenching of the fluorescence intensity of QDs was evaluated by the Stern-Volmer approach and K-SV and k(q) values were calculated. It was observed that the quenching was not diffusion controlled. The FRET parameters were also calculated by using fluorescence spectroscopy. The distances between donor-acceptor (r) were also calculated as 4.74 nm for QD1 and 2.26 nm for QD2. The steady-state transfer efficiencies were calculated as 0.24 and 0.53 for QD1 and QD2, respectively. The time-resolved transfer efficiencies were also determined as 0.11 for QD1 and 0.48 for QD2. The results demonstrated that the novel donor-acceptor pairs may play an important role in the applications of many research areas such as FRET-based nanosensors and light harvesting devices.