In the last time various new modified electrodes were developed and used as DNA biosensors. One of the general knowledge is focused on new types of screen-printed electrodes (SPE). Due to their specific behavior and ultimate applications as biosensors, the characterization of surfaces of SPE and the electrochemical processes speak on these electrodes need to be conceived. Besides common electrochemical methods the elimination voltammetry with linear scan (EVLS) is able to contribute to the electrochemical study of SPE features. The EVLS can be considered as a mathematical model utilizing linear sweep or cyclic voltammetry results to eliminate some selected particular currents from total voltammetric current and therefore it is capable to discover the rate determining step process or to characterize the influence of modified electrode surface on electrode processes. The elimination of selected particular currents and conservation the other ones is achieved by an elimination function formed from the total currents measured at different scan rates. The EVLS procedure eliminating kinetic and capacitive currents and conserving the diffusion current is very sensitive to the changes of electrode surfaces. In recently published papers it has been shown that this EVLS function is widely disposal in many electrochemical systems. In this work we attempt to apply the EVLS in the study of the novel screen-printed sensor modified not only by polysaccharide - chitosan (CHIT), but also by chitosan-multiwalled carbon nanotubes (MWNT) matrix