Enhancement of photoisomerization of polymethine dyes in complexes with biomacromolecules

► Photoprocesses in some polymethine dyes complexed with biopolymers are studied. ► The flash photolysis technique is applied. ► The study is concerned with meso-substituted thiacarbocyanine dyes. ► DNA and chondroitin-4-sulfate are used as the biopolymers. ► Formation of the dye (trans) photoisomer is detected in the dye-biopolymer complex.