Novel amperometric assay for drug-DNA interaction based on an inhibitory effect on an electrocatalytic activity of DNA-Cu(II) complex

► A novel strategy of amperometric assay of drug-DNA interactions was developed. ► This method was based on an inhibitory effect of drug on a catalytic activity of DNA-Cu(II) complex. ► Copper ion was incorporated in the DNA/polyallylamine membrane. ► The change of steady-state catalytic current was proportional to drug concentration. ► Kinetic analysis of the interaction was similar with the manner of enzyme inhibition.