The characteristics of the binding reaction of surfactant-cobalt(III) complex, cis-[Co(phen)(2)(C14H29NH2)]Cl-2 center dot 3H(2)O (phen =1,10-phenanthroline, C14H29NH2 = tetradecylamine) with human serum albumin (HSA) were studied by fluorescence and UV-vis absorption spectroscopy. In addition, the effect of the surfactant-cobalt(III) complex on the conformation of HSA was analysed using synchronous fluorescence spectroscopy. The experimental results showed that surfactant-cobalt( Ill) complex caused the fluorescence quenching of HSA through a combination of static and dynamic quenching. The number of binding sites (n) and apparent binding constant (K-a) of surfactant-cobalt(III) complex (above and below the critical micelle concentration (cmc) were determined at various temperatures. According to the thermodynamic parameters, it is likely that hydrophobic interactions are involved in the binding process. The cancer chemotherapeutic potential of surfactant-cobalt(III) complex on ME-180 cervical cancer cell was determined using MTT assay and specific staining techniques. The complex affected the viability of the cells significantly and the cells succumbed through an apoptosis process as seen in the nuclear morphology and cytoplasmic features. In addition, single-cell electrophoresis indicated DNA damage. (C) 2011 Elsevier B.V. All rights reserved.