In this work the interaction of DNA and the flavonoid-transition metal complex (Cu(II)-naringin complex) is characterized. The interaction was evaluated by using electrochemical ssDNA- and dsDNA-based biosensors and the results were supported by UV, CD and (1)H NMR data. In the electrochemical method, changes in the oxidation peak of the guanine and adenine bases obtained by square wave voltammetry (SWV) showed evidence of the interaction. The variations of the spectroscopic characteristics of DNA and Cu(II)-naringin complex in aqueous medium demonstrated that the predominant interaction mode may be by intercalation. Cu(II)-naringin complex interacts to dsDNA probably via N(7) of guanine site.