"Interaction of dopamine with graphene"

A.C. ROSSI FERNÁNDEZ; N.J. CASTELLANI

Sierra de la Ventana

Congreso; XLIII Reunión de la Sociedad Argentina de Biofísica; 2014

Sociedad Argentina de Biofísica

Dopamine (DA) is an important neurotransmitter that plays a significant role in the function of the central nervous, renal and hormonal systems. Ascorbic acid (AA) usually coexists with DA in biological systems with concentrations that are much higher than those of DA. Development of an efficient method for the determination of DA with high selectivity and sensitivity is a desirable objective for diagnostic uses. Because DA and AA are electroactive compounds electrochemical techniques for their detection have received large attention. Unfortunately, they shear a similar oxidation potential in electrochemical detection. Recently, various carbon materials have been proposed as electrodes to obtain a better response to DA molecules, including carbon nanotubes, carbon nanofibers, graphite and graphene (G). The latter in particular showed excellent performance, attributed to the pi-pi stacking interaction between DA and G surface. In this communication the interaction of DA with G was theoretically studied within the formalism of Density Functional Theory. The G system was represented by using a slab model where the G layer is replicated in the perpendicular direction with a gap of 10 Å between layers. The 2D supercell has 50 carbon atoms. Kohn-Sham eigenstates were obtained with the VASP code. Dispersive interactions were included according to the scheme of Grimme. Several DA/G geometrical configurations were considered, analyzing in each case the presence of non-covalent interactions. CONICET, ANCyT and UNS are acknowledged.