Simulação computacional da interação glifosato-C60 em meio aquoso.

Abstract

Glyphosate (N-(phosphonomethyl)glycine) is a widely used herbicide whose mechanism of action is the inhibition the EPSPs enzyme present in plants. However, its indiscriminate application has led to several environmental problems, in particular the contamination of various water reservoirs throughout the planet. In this sense, this work has the main objective to verify theoretically if it is possible glyphosate molecules to be adsorbed in vacuum and in aqueous media through its intermolecular interactions with C60 fullerene, which would make possible, in practice, the removal of these pollutants with nanotechnology techniques. Thus, we used computational simulations based on Molecular Dynamics (with the Universal Force Field) and Density Functional Theory (with LDA-PWC, GGA-PBE and B3LYP exchange-correlation functionals) to calculate the physical characteristics of the systems. Initially, the structural and optoelectronic characterization of the isolated glyphosate molecule was performed, showing the bond lengths, bond angles, torsion angles, frontier molecular orbitals, density of states plus their vibrational and thermodynamic properties. Accordingly, properties of the adsorption of glyphosate with C60 fullerene in vacuum and water were made by performing simulated annealing processes and calculating the potential energies of interaction in function of the distance between the respective centroids, quantum and classically.