Optical absorption bandshapes of Acridine Orange, Thionine, and Methylene Blue in monomeric and dimeric states

Abstract

The optical absorption bandshapes of the monomeric and dimeric states in aqueous solution of Acridine Orange, Thionine, and Methylene Blue are presented. They differ significantly from those previously reported. By making use of local field theory the positions and bandshapes of the dimer spectra can be well reproduced but the presence of an isosbestic point at low frequency is anomalous.