Docking of congo red to the surface of crystalline cellulose using molecular mechanics.

A method for the docking of ligands to crystalline surfaces using molecular mechanics was developed and applied to study the molecular features of the adsorption of Congo Red to cellulose crystals. The docking procedure was based on a grid search exploring the surface repeat unit of the cellulose crystals using several orientations of Congo Red at each grid point. Results suggest a preferential adsorption of Congo Red onto certain faces of the cellulose crystals and that the lower energy conformers have a similar positioning and orientation with respect to the cellulose chains at the surface repeat unit.