Electroanalytical applications of screen printed microelectrode arrays

We report the fabrication of screen printed microelectrode arrays which are comprised of six working electrodes (50 μm radii) which are separated from their nearest neighbour by an average distance of 2272 (±0.3) μm and arranged in a circular configuration around a common counter and reference electrode. Due to their facile fabrication, different inks can be used to give rise to both graphite- and gold-based screen printed microelectrode arrays. Additionally due to their fabrication design, the microelectrodes comprising the array are sufficiently separated to ensure no diffusional overlap which is commonly encountered by microelectrode arrays reported within the literature.The electrochemical sensing characteristics of the graphite screen printed microelectrode arrays are evaluated using acetaminophen, dopamine and nitrite giving rise to limits of detection (3σ) of 4.29, 3.24 and 5.24 μM respectively. Further to this, the gold-based screen printed microelectrode arrays are explored towards the electroanalytical sensing of chromium (VI) yielding a limit of detection (3σ) of 8.28 μM. Proof-of-concept is further demonstrated through the determination of chromium (VI) within an environmental (canal water) sample.Due to the analytically useful responses observed at the graphite and gold screen printed microelectrode arrays, these disposable and economical electrodes hold promise for in-the-field sensing applications. Additionally the working electrode composition can be readily changed through the use of the desired screen printing ink (i.e. Pd, Pt, Cu, etc.) allowing the tailoring of the electrode surface enabling electrocatalytic microelectrode arrays to be readily derived.