A new family of tryptophan based mixed-ligand complexes has been synthesized and characterized. DNA (Calf thymus) binding properties of the complexes have been explored by UV–vis, viscosity measurements and cyclic voltammetry. All the experimental evidence suggest that the ancillary ligand 2,2′-bipyridine influences the intercalative binding of these complexes to CT DNA. The DNA cleavage efficiencies of these complexes with pBR322 DNA were investigated by gel electrophoresis. The complexes were found to promote the cleavage of pBR322 DNA from the supercoiled form I to the open circular form II in the presence of an oxidizing agent (H 2 O 2 ). Microbial property of these complexes as antibacterial agents has been investigated against Gram-negative and Gram-positive bacteria.