Transfer of energy from thiacyanine to acridine orange and formation of exciplex between the two dyes bound to surfactants

Abstract

Energy transfer from donor thiacyanine and to the acceptor acridine orange and formation of exciplex between the dyes have been probed fluorimatrically in the presence of different concentrations of the surfactants sodium deoxycholate (NaDC), sodium cholate (NaC) and sodium salt of N-lauroyl sarcosine (NLS). All the three surfactants enhance the fluorescence of thiacyanine with efficiency of the order NaDC>NaC≅NLS. Results show that NLS facilitates both energy transfer and exciplex formation, whereas premicellar and micellar concentrations of NaDC favour only exciplex formation, but NaC facilitates neither phenomenon. The difference in behaviour of the surfactants has been thought to be due to difference in size and rigidity of the respective micelles. Premicellar concentrations of NLS favours exciplex formation and micellar and post micellar conditions favour energy transfer.