The powders of unmodified silica, as well as silicas modified with poly(ethyleneimine) and 3-aminopropyltriethoxysilane are synthesized by the sol-gel method. The obtained powders and their suspensions in water are characterized by IR spectroscopy, atomic force microscopy, and spectroturbidimetry. The adsorption ability of D-glucose on the surface of the aforementioned powders is studied. It is shown that this monosaccharide is not adsorbed on the surface of unmodified silica, but is adsorbed on the surface of aminated silicas. The differences in the interaction of D-glucose with the studied particles are discussed from the viewpoint of the nature of surface chemical groups.