The present disclosure relates drilling fluids and methods of producing and using drilling fluids. The drilling fluid includes an aqueous base fluid; a clay-based component; and a shale inhibitor comprising silica grafted with glutamate-glycol. The method of producing the drilling fluid includes reacting silica with glutamate and glycol thereby forming a shale inhibitor comprising silica grafted with glutamate-glycol; and mixing an aqueous base fluid, a clay-based component, and the shale inhibitor to produce a drilling fluid. The method of using the drilling fluid in drilling operations includes mixing an aqueous base fluid, a clay-based component, and a shale inhibitor comprising silica grafted with glutamate-glycol to produce a drilling fluid; and introducing the drilling fluid to a subsurface formation.