Screen printed graphene electrodes for voltammetric dopamine determination

In this work, new graphene-based screen-printed electrodes are proposed as a new, cheaper alternative to more common electrodes for determination of dopamine. Electrodes were designed, manufactured and tested to look for correlations between different graphene weight percentages used in electrodes and oxidation peaks and sensitivity in dopamine determination. All electrodes were tested using cyclic voltammetry. For a reference, graphite electrodes were tested. With sensitivity of 0.0161 µA/µM and detection limit of 5.549 µM those electrodes showed potential promise in use of graphene for electrode material. In electrodes manufacturing, Laroflex® and PMMA based vehicles were mixed in with graphene platelets with diameters ranging over 2 µm and thickness between 8-15 nm. Initial tests with electrodes screen printed with graphene layers of 150 µM showed very low response. 0.0077 µA/µM sensitivity and 11.970 µM detection limit were achieved with Laroflex® based electrodes. Further testing with thicker layers gave more impressive results with detection limit going as low as 1.349 µM and 0.1343 µA/µM sensitivity. Such results bring those electrodes to comparable level with other electrodes available.