7 research outputs found
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 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)