Electrochemical and Theoretical Study of π–π Stacking Interactions between Graphitic Surfaces and Pyrene Derivatives

In this study, the reversibility of π–π stacking interactions at graphite electrodes (GE) of pyrene, 1-aminopyrene, 1-pyrenecarboxylic acid, and doxorubicin hydrochloride (DOX) have been studied. The adsorption and desorption of these π-orbital-rich molecules was characterized using X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV). The experimental investigations were complemented with a density functional theory study of the interaction between these π-orbital-rich molecules and graphite. It was demonstrated that the charged pyrene derivatives could be electrochemically desorbed from the graphitic surfaces, when a sufficiently high potential of the same charge as the pyrene derivative, was applied to the electrode. The duration of the applied potential, the pH and the magnitude of the applied potential during potential pulsing were found to be important with regards to the desorption efficiency. Up to 90% of charged pyrene derivatives could be removed from the electrode surface within 6...