A Spectroscopic Study of the Interaction Between the Bismarck Brown R–Eu(III) Complex and DNA

The interaction of the Eu(III)–BBR complex with herring sperm DNA is investigated using an acridine orange (AO) probe for UV-vis absorption spectroscopy and fluorescence spectroscopy. The results indicate that both the AO probe and the Eu(III)–BBR complex can intercalate into the base pairs of DNA. The binding constants of the Eu(III)–BBR complex with DNA are $$ {K}_{298.15K}^{\theta } $$ = 1.58·104 L/mol and $$ {K}_{308.15K}^{\theta } $$ = 9.35·104 L/mol, and the binding process is entropydriven. It is shown that the interaction modes between the Eu(III)–BBR complex and DNA include groove binding and intercalative binding. The mechanism of the interaction between the Eu(III)–BBR complex and DNA will provide an important theoretical basis for the synthesis of new drugs.