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

Abstract

In this study, the reversibility of π−π stacking interactions at graphite electrodes (GE) of pyrene, 1aminopyrene, 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 60 s via potential pulsing. However, these parameters produced insignificant effects on neutral pyrene bound to the graphite. A potential application of this electrochemically induced desorption of π-rich species in drug delivery was demonstrated via the release of adsorbed doxorubicin (DOX).

Self-assembled CeO2 on carbon nanotubes supported Au nanoclusters as superior electrocatalysts for glycerol oxidation reaction of fuel cells

“…Thus, the weight loss of PC-MWNT in this region is caused by the decomposition of PC, and the weight percentage of PC wrapped on MWNT was calculated to be 1.49%. This result further confirms that PC has been self-assembled on MWNT, most likely via the π-π stacking between the pyrene structure in PC and graphitic surface of CNTs [43,44]. crystal structure, respectively [27,45,46].…”

Biohydrogen for a New Generation of H2/O2 Biofuel Cells: A Sustainable Energy Perspective

“…[178][179][180][181][182] Following the same idea, graphite electrodes, either bare or modified by CNTs, were modified with aryl diazonium salts, [66] pyrene derivatives, [57,[183][184][185] or benzoic acid derivatives. [186] Accurate observations revealed a decrease in the hysteresis of the onset of O 2 reduction [57] related to the enzyme orientation of Sreptomyces coelicolor (Sc) LAC, which helps in the efficient bioelectrocatalysis in neutral media and in the presence of chloride.…”

Effects of Substituents on the Electrocatalytic Activity of Cobalt Phthalocyanines when Conjugated to Graphene Quantum Dots

“…Geometric and substituent effects on π‐π interactions may be explained by Hunter‐Sanders model , which argues that even though dispersion effects are important to the total binding energy, changes due to geometry or substitution are governed by electrostatic forces. The model describes an aromatic ring as a positively charged σ‐framework and a negatively charged π‐cloud.…”