Preanodized screen-printed carbon electrodes (SPCEs*) lower the oxidation overpotential and improve the peak current of phenols because of the presence of hydroxyl groups on the surface of SPCEs*. These hydroxyl groups can form hydrogen bonds with the OH groups of the phenols. The oxidation peak potential (E-pa) is linearly related to the number of hydroxyl groups on the surface of SPCEs*. Moreover, the E-pa of phenols at SPCEs* was found to systematically shift depending on the substituents on the phenols. The shifts in the E-pa are strongly associated with Hammett's constant. (C) 2012 Elsevier B.V. All rights reserved.