A simple heterogeneous synthesis of pure modified porous polysiloxane SiO2 by condensing a functionalized C,C-pyridylpyrazole with a 3-glycidoxy-propyltrimethoxy-silane silylant agent, previously anchored on a silica surface is reported. The epoxide group was opened yielding a receptor pendant group bonded to the inorganic surface. The surface modification (MS) was characterized by elemental analysis, infrared spectra, nitrogen adsorption-desorption isotherm, BET surface area and B.J.H. Pore sizes. The new material exhibits good chemical and thermal stability determined by thermogravimetry curves. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 3345-3349, 2010