Fluorescence Energy Transfer Characteristics in Binary Acriflavine-Red Nut Lasing Dye Mixtures

Abstract

In this work, the energy transfer characteristics in binary lasing dye mixtures were studied by the measurements of fluorescence spectra using two different techniques at room and low temperatures. The binary lasing dye mixtures were made from acriflavine (donor) and red nut (accepter) dyes dissolved in two different solvents at different concentrations. These characteristics were determined throughout the variation of some related parameters, such as the fluorescence intensities of donor in the absence and the presence of acceptor (ID/IDA), the half quenching concentration (A1/2) and the critical transfer distance (R0), with accepter (red nut) concentration at different concentrations of prepared solutions. Results showed that both ID/IDA and R0 increased with acceptor concentration while A1/2 decreased with increasing acceptor concentration. Also, the monomer sample in ethanol exhibited higher values of all three parameters (ID/IDA, R0 and A1/2) with respect to those obtained from monomer in methanol at certain concentration. The minimum value of R0 was measured in 10-5 M/L monomer sample in methanol at accepter concentration of 10-5 ml.