Fig. 1.

Fluorescence spectra of Acf (1), RhB (2), and Acf + RhB (3) (1:1 volume ratio) in water solution. Excitation wavelength was 420 nm (Acf absorption maximum) and concentration of individual dye (pure Acf and RhB) 10^− 6 M. Inset (1) shows the normalized absorption spectrum of rhodamine B and fluorescence spectrum of acriflavine in water solution and inset (2) shows the excitation spectra for Acf+RhB mixture with emission wavelengths at 500 nm (a) and 578 nm (b)