Cytochrome c immobilization into mesoporous molecular sieves

The immobilization of cytochrome c into the mesoporous moleclar sieves MCM-48 (Mobil Composition of Matter) and SBA-15 (Santa Barbara Amorphous), as well as the layered niobium oxide Nb-TMS4 (Niobium Transition Metal Oxide Molecular Sieve) is described. The cytochrome c loading was influenced by the molecular sieve structure, i.e., one-dimensional vs. three-dimensional. Cytochrome c immobilization was accomplished by absorption into the molecular sieves followed by silylation of the pore openings. The molecular sieves containing cytochrome c were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV/Vis, and FT-IR spectroscopy. The protein was found to be stable in the molecular sieve under conditions that would denature the protein in solution. The immobilized cytochrome c retained its redox activity following immobilization for several months as demonstrated by cyclic voltammetry (CV).