The interaction of mitomycin C (MC) with fish sperm or calf thymus DNA immobilized onto carbon screen-printed electrodes (CSPE) and carbon paste electrode (CPE) have been studied by using electrochemical techniques as square wave voltammetry (SWV) and differential pulse voltammetry (DPV). After the interaction was occurred between DNA and MC on electrode surface. it was observed that the guanine signal was higher with bare electrode than DNA-modified one. The changes in the experimental parameters such as the concentration of MC, and the accumulation time of MC were studied by using SWV and DPV. In addition, reproducibility, and detection limit parameters were determined using both electrodes. The partition coefficient of MC was also calculated before and after interaction of MC with dsDNA at CPE surface. These results showed that these two different DNA biosensors could be used for the sensitive, rapid and cost effective detection of MC-DNA interaction. (C) 2004 Elsevier B.V. All rights reserved.