Polymer complexes [Cu(dpq)2BPEI](ClO4)2·2H2O (dpq-dipyrido[3,2-d;2′,3′-f]quinoxaline; BPEI-branched polyethyleneimine] with different degrees of copper complex content in the polymer chain (x) were synthesized and characterized by UV-Vis, IR, EPR and elemental analysis methods. Absorption spectroscopy, emission spectroscopy, cyclic voltammetry and circular dichroism techniques were used to investigate the binding nature of these polymer–copper(II) complexes with both CT-DNA and yeast tRNA. These experiments revealed that these the polymer–copper(II) complexes bind to both DNA and RNA by an intercalation mode via ligand dpq into the base pairs of DNA/RNA. The binding constant of the polymer–copper(II) complex increases with the degree of coordination. Furthermore, the anti-microbial effects and in vitro cytotoxicity of one of the polymer copper(II) complexes (x = 0.326) were investigated using the disk diffusion method and MTT assay and AO/EB staining. These results suggests that the polymer–copper(II) complex can be used as an effective therapeutic agent.
