In this study, the interaction between the phosphodiesterase-3 enzyme inhibitor drug milrinone and biomolecules was investigated by electrochemical, fluorescence spectroscopy, and molecular docking studies for the first time. The interaction between milrinone and biomolecules was investigated according to the decrease in deoxyguanosine oxidation signals of milrinone and calf thymus double-stranded deoxyribonucleic acid (ct-dsDNA) by cyclic voltammetry and differential pulse voltammetry. In fluorescence spectroscopy studies, a competitive study was conducted on ct-dsDNA by adding a well-known fluorescent methylene blue and ct-dsDNA solution. The fluorescent results showed that milrinone had a higher affinity for ct-dsDNA binding compared to methylene blue. Interaction studies show that milr...