Synthesis, CMC determination and nucleic acid-binding interaction of a surfactant copper(II) complex containing amino acid–Schiff base ligand:[Cu(sal-ala)(bpy)(DA)

Abstract

The surfactant copper(II) complex, [Cu(sal-ala)(bpy)(DA)] (sal-ala = amino acid Schiff base, bpy = 2,2′-bipyridyl, DA = dodecylamine) has been synthesized and characterized by elemental analysis, UV–Vis, IR and EPR spectra. The critical micelle concentration (CMC) values of this surfactant copper(II) complex in aqueous solution was obtained from conductance measurements. Specific conductivity data (at 303, 308, 313. 318 and 323 K) served for the evaluation of the temperature-dependent CMC and the thermodynamics of micellization (Δ $$G_{\text{m}}^0$$ , Δ $$H_{\text{m}}^0$$ and Δ $$S_{\text{m}}^0$$ ). Absorption, fluorescence, cyclic voltammetry, circular dichroism spectroscopy and viscosity experiments have been carried to study the interaction of this surfactant complex with nucleic acids. The results suggest that the complex could bind to nucleic acids by intercalation via salicylidene aromatic chromophore into the base pairs of CT DNA. The long aliphatic chain of the surfactant complex increases the hydrophobic interaction between the complex and nucleic acid. The surfactant copper(II) complex was screened for their antibacterial and antifungal activities against various microorganisms. The results were compared with the standard drugs, amikacin (antibacterial) and ketokonazole (antifungal).