We have designed and synthesized 1,8-naphthalimide-based ligand N-(4-pyridyl)-1,8-naphthalimide (L) and its mixed ligand complex 1 [Cu(phen)2(L)](ClO4)2, where L = N-(4-pyridyl)-1,8-naphthalimide; phen=,10-phenanthroline. The synthesized copper complex has been structurally characterized with a single crystal X-ray determination study. The coordination geometry around the complex 1 is found to be distorted square pyramidal with N5 donor sites. The CT-DNA (calf thymus DNA) binding ability of the complex has been studied with various spectroscopic techniques such as UV–Vis and fluorescence spectroscopy. The viscosity measurements and circular dichroism (CD) spectral studies were also been studied to determine the CT-DNA binding mode. All the above studies indicate the groove binding mode of complex 1 to the CT-DNA. The interaction of bovine serum albumin (BSA) to the copper complex was investigated using fluorescence spectral studies and it is found to follow a dynamic quenching mechanism.