Application of a europium complex, Eu(AA)3phen (AA = acrylic acid, phen = 1,10-phenanthroline) as a spectroscopic probe and cleaving reagent of DNA

A complex Eu(AA)3phen was synthesized and characterized by elemental analysis, IR spectroscopy and 1H NMR. Interaction between Eu(AA)3phen and DNA was studied by UV/visible absorption spectroscopy, fluorescence spectrophotometer, circular-dichroism (CD) spectra and gel-electrophoresis measurements. Absorption spectral indicated that Eu(AA)3phen binding to DNA was an electrostatic mode, which was authenticated by the effect of ionic strength, thermal denaturation and fluorescence quenching experiments. The intrinsic binding constant Kb of Eu(AA)3phen was calculated to be 1.6 × 104 L mol− 1.