THE INFLUENCE OF PRINTING PROPERTIES OF SCREEN PRINTED ELECTRODES ON SENSITIVITY MEASURED WITH CYCLIC VOLTAMMETRY

Disposable screen printed electrodes are widely used for environmental monitoring such as water quality test, heavy metals detection and gas pollutants. (Hayat et al, 2014; Li et al, 2012) Screen printed electrodes used for electrochemical detection consist of three electrodes: auxiliary, working and reference electrode. The working electrode is the principal electrode on which electrochemical reactions are performed, while the reference and auxiliary electrodes are used to complete the electronic circuit. (Hayat et al, 2014) To produce efficient screen printed electrodes the modification of the electrode surface or altering of the geometry of electrode can be done. Researchers mostly modify the surface of the electrode, but on the other hand, there are many properties that can be changed and optimized at the beginning, in the process of screen printing. In the presented research the influence of the modification of the working electrode area and conductive ink thickness on the final electrochemical activity was evaluated. Besides that, a modification of conductive printing ink was done using carbon nanotubes. Finally, electrochemical activity of all samples was analyzed with potassium ferricyanide K3[Fe(CN)6]. It was found that the highest impact on electrochemical activity has conductive ink thickness. Working electrode area also affects the electrochemical activity, but less, while modification of conductive ink with the addition of carbon nanotubes does not have significant influence. The main reason for that was immersing of nanotubes into the ink and consequently, the specific surface of the modified working electrode remains comparable to non-modified one.