In this work, we report a new hybrid nanomaterial based on the immobilization of 4-formyl benzo-9-crown-3 ether (FB9C3) onto the mesopores of MCM-41. First, the mesoporous molecular sieve MCM-41 was covalently grafted with 3-aminopropyl triethoxysilane to give aminopropyl modified MCM-41 (AmpMCM-41). Reaction of this material with FB9C3 afforded the B9C3-AmpMCM-41 hybrid nanomaterial. The prepared B9C3-AmpMCM-41 was characterized with different physicochemical methods such as Fourier transform infrared spectroscopy, X-ray diffraction (XRD), scanning and transmission electron microscopy, thermogravimetric analysis (TGA-DTA), and BET nitrogen adsorption-desorption analysis. The XRD analysis revealed that textural properties of the support were preserved during the immobilization process. However, nitrogen adsorption-desorption analysis showed sequential reduction in surface area, pore volume, and pore size during the grafting experiments. Elemental analysis showed the presence of 0.11 mmol FB9C3 per gram of the hybrid nanomaterial.